Photocatalytic Solar Light H2 Production by Aqueous Glucose Reforming

Article abstract of DOI:10.1002/ejic.201800663

A series of tungsten and nitrogen doped Pt-TiO₂ samples were prepared with the aim to extend the TiO₂ absorption to the visible light region and to enhance the separation efficiency of the photogenerated electron/hole pairs. The physicochemical features of the powders were characterized by X-ray diffraction (XRD), UV/Vis reflectance spectra, specific surface area (SSA) determinations, and transmission electron microscopy (TEM) analyses. The influence of the presence of different doping agents was evaluated, under anaerobic conditions, in the aqueous photo-reforming of glucose to form H₂ at ambient pressure and temperature under a halogen lamp or natural solar light irradiation. Arabinose, erythrose, and formic acid were the main glucose partial oxidation products observed in the liquid phase, whilst H₂ and CO₂ were measured in the gaseous phase. The highest H₂ production was observed in the presence of the Pt-TiO₂-W0.25 sample.

Full text of DOI:10.1002/ejic.201800663

DOI: 10.1002/ejic.201800663
Full Paper
Aqueous Glucose Reforming
Photocatalytic Solar Light H2 Production by Aqueous Glucose
Reforming
Marianna Bellardita,*[a] Elisa Isabel García-López,[a] Giuseppe Marcì,[a] Giorgio Nasillo,[b] and
Leonardo Palmisano*[a]
Abstract: A series of tungsten and nitrogen doped Pt-TiO2 doping agents was evaluated, under anaerobic conditions, in
samples were prepared with the aim to extend the TiO2 absorp- the aqueous photo-reforming of glucose to form H2 at ambient
tion to the visible light region and to enhance the separation pressure and temperature under a halogen lamp or natural so-
efficiency of the photogenerated electron/hole pairs. The phys- lar light irradiation. Arabinose, erythrose, and formic acid were
icochemical features of the powders were characterized by X- the main glucose partial oxidation products observed in the
ray diffraction (XRD), UV/Vis reflectance spectra, specific surface liquid phase, whilst H2 and CO2 were measured in the gaseous
area (SSA) determinations, and transmission electron micros- phase. The highest H2 production was observed in the presence
copy (TEM) analyses. The influence of the presence of different of the Pt-TiO2-W0.25 sample.
1. Introduction
splitting is a very hard and disadvantageous process by a ther-
modynamic and kinetic point of view. Biomass conversion is
less energy demanding than water splitting. The use of glucose,
glycerol, lignin, etc., as sacrificial agents, can reduce the elec-
tron/hole recombination rate and favour selectively the synthe-
sis of high value-added products.[6,13–22] There are still only a
relative small number of materials that can efficiently photore-
form biomass, and works dedicated to improving the efficiency
of photocatalysts, especially under natural solar light irradiation,
are useful. TiO2 is the most employed photocatalyst for this
process because of its low cost, chemical and photochemical
stabilities, and ease of preparation.[16,23]
TiO2 photoactivation presents some weaknesses due to its
high electron/hole recombination rate and the need of UV
light.[24] Many approaches have been explored to improve the
TiO2 efficiency and to better exploit the solar radiation, as
doping with metal[25–27] and non-metal species,[28–30] co-dop-
ing,[31–33] surface modification by organic species sensitiza-
tion,[34,35] coupling of different semiconductors.[36–39]
Among the nonmetallic elements, since the work of Asahi et
al.,[40] a great attention has been addressed to N doped TiO2
because it is reported that the band gap of TiO2 becomes
smaller, due to formation of a mid-gap energy state above the
valence band[41–43] and presence of oxygen vacancies generat-
ing color centers.[44] N-TiO2 samples have been employed also
for glucose photo-reforming.[45–46] Ilie et al.[45] compared the
photoactivity of a series of Au-TiO2 samples dispersed on SiO2
and doped with metal (Mn, Cr, V) or non-metal (N or S) species
towards the H2 production from aqueous sugar solution. The
best results were obtained in the presence of non-metals and
were attributed to a lower tendency to form recombination
centers with respect to samples doped with metals.
In the last decades, there has been a growing interest in renew-
able energy sources, due to both the almost exhaustion of the
fossil fuels currently used, and the growth of environmental
pollution with damaging effects for the ecosystem and health
of people. The use of renewable sources can efficiently help to
solve these issues and, among them, hydrogen is a clean energy
carrier, because its combustion with oxygen produces only wa-
ter.[1–3]
Nowadays, the dominant industrial processes for hydrogen
production are steam reforming from hydrocarbons,[1] biomass
conversion processes (such as direct combustion, gasification,
pyrolysis)[4–6] and water splitting by means of different technol-
ogies: electrolysis, radiolysis, thermolysis, photobiology and
photocatalysis.[7,8] Most of these methods are not economically
sustainable as they require large equipment, high temperature
and pressure, and significant energy consumption.[9]
To ensure that this new energy carrier is effectively “green”,
hydrogen production has to be as clean as possible. In this
scenario heterogeneous photocatalysis, under ambient condi-
tions and in the presence of green solvents and sunlight irradia-
tion, represents one of the cleanest way to directly split water
into hydrogen and oxygen.[10–12] Unfortunately, the direct water
[a] “Schiavello-Grillone” Photocatalysis Group, Dipartimento di Energia,
Ingegneria dell′informazione, e modelli Matematici (DEIM), Università degli
Studi di Palermo,
Viale delle Scienze Ed. 6, 90128, Palermo, Italy
E-mails: marianna.bellardita@unipa.it, leonardo.palmisano@unipa.it
http://www.unipa.it/photocatalysis
[b] Laboratorio di Microscopia Elettronica a Trasmissione-Advanced
Technologies Network Center (ATeN), University of Palermo,
Viale delle Scienze Ed. 17, 90128, Palermo, Italy
As far as the metallic species are concerned, tungsten has
attracted the attention of many researchers because the pres-
ORCID(s) from the author(s) for this article is/are available on the WWW
under https://doi.org/10.1002/ejic.201800663.
Eur. J. Inorg. Chem. 0000, 0–0
1
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
ence of WO3 in the TiO2 lattice can enhance the separation of nitrogen did not alter the phase composition (Figure 1A),
efficiency of the photogenerated charges, while the presence whilst the appearance of anatase was observed in the presence
of cations (W6+ and/or W4+) substituting Ti4+ ions, can modify of tungsten, and it increased with the amount of the dopant
the TiO2 electronic structure.[47,48] Due to the different behav- (Figure 1B), according to what previously observed.[60] Broad
iour of metals and non-metals, co-doping was used as a strat- peaks were obtained, suggesting a poor crystallinity of the sam-
egy to enhance the photocatalytic activity of TiO2.[33,49–52] It is ples due to the low preparation temperature. The absence of
reported that anions and cations generate shallow localized lev- peaks related to N and W species can be ascribed to the low
els near the valence and conduction band edges, allowing the amount of dopants and to a high degree of dispersion of the
band gap decrease and the shift of the two bands towards less loaded species on the TiO2 surface. The crystallites size ranged
positive and less negative values, respectively.[53] Various N, W between 5.6 and 12.5 nm (Table 1) and the highest values were
co-doped TiO2 systems have been prepared and tested under measured for the samples containing the highest percentages
solar light irradiation for oxidation reactions.[54–57] In those of dopant species. The slight broadening of the peaks after
cases, isolated N 2p states are located above the valence band doping may be due to the formation of structural defects in
edge whilst W 5d states below the conduction band edge.
The obtainment of high value-added chemicals from bio-
mass derived compounds has been the subject of intense re-
search in recent years.[58–59] In this context the use of glucose
appears interesting because it is an abundant and cheap mono-
saccharide.
the presence of foreign ions.
Table 1. Phase composition, crystallite size (Φ), band-gap (Eg), specific surface
areas (SSA) of the prepared samples (in brackets the mid-gap values are re-
ported).
Sample
Phase
Φ
[nm]
Eg
[eV]
SSA
[m2 g–1
]
The aim of the work reported in this paper was to synthesize
Pt-TiO2-rutile based materials doped with N or W species which
were used under ultraviolet (UV), halogen lamp (HL) or natural
solar light (SOL) irradiations to obtain H2 by photo-reforming of
a glucose aqueous solution. Rutile TiO2 polymorph was chosen
because it has been reported to show a photocatalytic H2 pro-
duction efficiency higher than that of the anatase phase, under
similar experimental conditions.[22]
TiO2
Pt-TiO2
R
R
R
R
R
R
R+A
R+A
A+R
R
5.6
7.7
7.9
12.5
12.1
8.8
2.98
21
7
1
≈ 1
≈ 1
66
64
18
28
3.4
2.90 (2.45)
2.86 (2.47)
2.74 (2.41)
2.72 (2.42)
3.26 (2.95)
3.16 (2.96)
2.92 (2.57)
2.86 (2.49)
2.88 (2.48)
Pt-TiO2-N0.5
Pt-TiO2-N1
Pt-TiO2-N2
Pt-TiO2-W0.25
Pt-TiO2-W0.5
Pt-TiO2-W1
Pt-TiO2-W2
Pt-TiO2-N0.5W0.5
7.7
12.4
10.3
7.5
2. Results and Discussion
The bare TiO2 exhibited a specific surface area (SSA) of
21 m2 g–1, that decreased in the presence of Pt and nitrogen,
whilst an increase was observed when W was loaded. The sam-
2.1 Characterization of the Photocatalysts
The XRD patterns of the pristine and doped samples are shown ples containing N showed very low values of SSA (about
in Figure 1. The bare TiO2 consisted of pure rutile; the presence 1 m2 g–1), and when tungsten was present, the increase was
Figure 1. XRD patterns of N-doped (A) and W-doped (B) TiO2 samples. A = Anatase, R = Rutile.
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
2
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
the highest in the presence of the lowest amounts of metal
(0.25 and 0.5 weight %) whilst only small variations occurred
with the highest quantities. The pore volume was 0.018 cm3 g–1
for pristine TiO2, decreased by adding Pt (0.005 cm3 g–1) and
further with nitrogen down to 0.003 cm3 g–1 whilst an increase
occurred in the presence of tungsten, reaching the value of
0.03 cm3 g–1. The increase of the pore volume for the W-doped
samples with respect to the N-doped ones (0.03 vs.
0.003 cm3 g–1) may partly justify the higher surface areas of the
first samples, although the crystallites size for all of the doped
samples is not dramatically different. The surface area and pore
volume decrease observed after addition of Pt can be due to
the pore blockage by the metal. Their variation in the presence
of foreign species, instead, can be ascribed to surface modifica-
tions, as confirmed by TEM analyses.
The nitrogen adsorption-desorption isotherms (Figure 2) cor-
responded to Type IV isotherm[61] and showed a hysteresis loop
of H4 type, with the two branches almost horizontal and paral-
lel over a wide range of p/p° for the samples TiO2, Pt-TiO2 and
Pt-TiO2-N0.5, while for the sample Pt-TiO2-W0.5 the hysteresis
loop is intermediate between the types H3 and H4. These re-
sults suggest that the appearance of the hysteresis loop is more
probably due to agglomeration of the particles, although also
pores smaller than 100 Å have been identified by the size distri-
bution analysis for the samples containing W.
Figure 3. TEM micrographs of the bare TiO2 sample at 10000x (A) and 50000x
(B) magnifications and of Pt-TiO2 sample at 10000x (C) and 50000x (D) magni-
fications.
A situation even more different was observed for the pow-
ders containing N or W. The sample Pt-TiO2-N0.5, for instance,
shows the presence of strange long needle-like particles (Fig-
ure 4A–B) whilst big and thick particles with irregular shape,
whose dimension range from few tens up to hundreds of ma-
nometers, can be noticed for the Pt-TiO2-W0.5 sample (Figure 4
C–D).
These results indicate that the different dopants influenced
also the morphology of the samples.
In Figure 4(E–F) the sample Pt-TiO2-W0.25 before (E) and
after (F) its use in photocatalytic runs is shown. After the photo-
catalytic test no significant differences of shape and dimension
of the particles can be noticed, but the clusters appear slightly
bigger (Figure 4F), due to some aggregation which took place
during the run.
High Resolution TEM (HR-TEM) and selected area electron
diffraction (SAED) analysis of sample Pt-TiO2-W0.25 (Figure 5)
show that the obtained rutile is well crystallized with clear par-
allel lattice fringes. The fringe spacing is approximately 0.32 nm,
which correspond to the (1 1 0) lattice spacing of rutile TiO2.[62]
In the inset of Figure 5 a sharper image (processed through
an Inverse Fast Fourier Transform) of the highlighted area and
the histogram showing the exact calculation of d-space are re-
Figure 2. N2 adsorption-desorption isotherms of some representative sam-
ples.
TEM micrographs of the bare TiO2 sample (Figure 3A–B) ported. Moreover, HR-TEM micrographs confirm that the crystal-
show the typical morphology of rutile nanoparticles: cluster of line structure did not change after the catalytic test.
elongated rod-like particles with sharp borders and length of
some tens of nanometers.
In Figure 6 the reflectance spectra of bare TiO2, Pt-TiO2, Pt-
TiO2-N and Pt-TiO2-W samples are reported. In the presence of
By adding platinum (sample Pt-TiO2 Figure 3C–D) the mor- Pt an increase of the absorption in the visible light region, with
phology becomes quite different: clusters become bigger, respect to the bare TiO2, occurred, whilst a slight decrease was
consisting of more particles. Notably, the shape of the single observed in the presence of nitrogen. The light absorption
particles changes significantly, becoming almost round with above 500 nm of the Pt-TiO2-N and Pt-TiO2-W samples can be
diameter less than 10 nm.
attributed to oxygen vacancies, in accordance with the litera-
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
3
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
(Figure 7). Bare TiO2 exhibited a band gap of 2.98 eV which is
typical of the rutile polymorph, reduced to 2.90 eV after Pt add-
ing. A progressive decrease of the band gap values was ob-
served (Table 1) at increasing nitrogen amount. This is probably
due to a broadening of the valence band following the hybridi-
zation of the O 2p states with the N 2p states, with a conse-
quent upward shift of the valence band maximum. In the pres-
ence of tungsten there was a band-gap increase, with the ex-
ception of the samples with the highest tungsten percentages
and the Pt-TiO2-N0.5W0.5 sample for which a decrease of the
band-gap occurred. The band bap increase in the samples con-
taining W can be attributed to the formation of the anatase
phase (the band gap of anatase is higher than that of rutile)
whose quantity rises with the W amount. For the highest W
percentage two phenomena can take place which contribute
in opposite way to the band gap value: the increase of the
anatase fraction and the shift towards higher potential values
of the CB edge with the W amount.[66] As reported in Table 1,
Figure 4. TEM micrographs of the samples Pt-TiO2-N0.5 (A and B), Pt-TiO2-
W0.5 (C and D) and Pt-TiO2-W0.25 before (E) and after (F) the photocatalytic
runs.
Figure 5. High resolution TEM images of the sample Pt-TiO2-W0.25 before (A)
and after (B) the photocatalytic runs. Inset: processed image of highlighted
area and plot profile of atomic fringe showing the calculations of d-spacing.
ture.[63,64] In Figure 6B it can be noticed that the spectrum of
Pt-TiO2 is red shifted with respect to those of the samples con-
taining W because the sample mainly consists of rutile phase.
Tungsten stabilized the anatase phase,[65] its presence blue
shifted the absorbance of the samples and increased the per-
centage of reflectance. The band gap values (Table 1) were ob-
tained by extrapolating a linear fitting in the Tauc plot diagram
Figure 6. DRS spectra of the various photocatalysts.
4 © 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org

Full Paper
indeed, there is a progressive band gap reduction with increas-
ing tungsten percentage despite the increased quantity of
anatase. The presence of surface oxygen vacancies in the doped
samples could also play a role in determining the band gap
value.
Figure 8. Concentration of: (Violet triangle) glucose, (Black cross) arabinose,
(Red star) erythrose and (Orange ball) formic acid in liquid phase and (Blue
diamond) CO2, (Green square) H2 in gas phase, vs. irradiation time under UV
light irradiation in the presence of some photocatalysts (A–C) and amounts
of H2 and CO2 per gram of catalyst after 6 h of irradiation (D). The error of
analysis is less than 5.
In Table 2 the glucose conversion and the selectivity towards
the different by-products are reported. After 6 h of UV irradia-
tion the substrate conversion was 45.8 % by using the Pt-TiO2
sample, a small increase was obtained by adding 0.5 % of nitro-
gen, and a significant reduction was observed in the presence
of 0.5 % of tungsten. With regard to the selectivity towards
arabinose, no great variation was observed in the presence of
the three samples; the selectivity to formic acid was reduced
by the presence of foreign elements, and a difference was ob-
tained in the distribution of the oxidation products. In particu-
lar, no erythrose was detected in the presence of the Pt-TiO2-
W0.5 sample. The results confirm that glucose oxidation oc-
curred with the C1–C2 break, following the mechanism re-
ported in Figure 9, in accordance with literature.[19,22] The high-
est H2 production (715 μmol g–1 after 6 h of irradiation, Fig-
ure 8D) was measured with the non-doped sample and both
N and W caused a decrease, obtaining the lowest amount with
the addition of W. Similar CO2 amounts were detected in the
presence of the three samples.
Figure 7. Tauc plot diagram of the various photocatalysts.
The spectra of the TiO2 and Pt-TiO2 samples exhibited a sin-
gle sharp edge while those of the doped samples showed two
linear sections, being the second attributable to the existence
of a mid-gap band located above the valence band[42,64] or be-
low the conduction band, due to the additional energy levels
created by the doping agents.
2.2 Photocatalytic Runs
No formation of H2 occurred in the presence of bare TiO2, con-
firming the essential role of Pt. The results of the photocatalytic
runs carried out under UV light irradiation in the presence of
Pt-TiO2, Pt-TiO2-N0.5, and Pt-TiO2-W0.5 samples are reported in
Figure 8. Concentration of glucose and its partial oxidation
products in liquid phase, along with H2 and CO2 in gas phase,
vs. irradiation time are reported in Figure 8A–C whilst the
amounts of H2 and CO2 per gram of catalyst obtained after 6 h
of irradiation are reported in Figure 8D. Notably, no CO and/
or CH4 were detected under the experimental conditions used.
Table 2. Glucose conversion (X) and selectivity (S) to arabinose, erythrose and
formic acid after 6 h of UV irradiation.
Sample
Xglucose
Sarabinose
Serythrose
Sformic acid
Pt-TiO2
Pt-TiO2-N0.5
Pt-TiO2-W0.5
45.8
48.4
23.3
40.7
38.3
36.4
11.4
13.6
–
58.6
41.1
35.5
In Figure 10 the trend of the concentration of all of the spe-
Arabinose, erythrose and formic acid were the main observed cies measured during the photocatalytic runs carried out under
species deriving from the partial glucose oxidation, according a halogen lamp irradiation in the presence of the different sam-
to previous results.[22]
ples is reported. The amount of both CO2 and H2 increased
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
5
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Figure 9. Hypothesized oxidation path of glucose.
Figure 10. Concentration of: (Violet triange) glucose, (Black cross) arabinose, (Red star) erythrose, (Orange ball) formic acid in liquid phase, (Blue diamond)
CO2, (Green square) H2 in gas phase, vs. irradiation time under HL irradiation. The error of analysis is less than 5.
as the glucose concentration decreased. Glucose oxidation can same, regardless of the irradiation source used. In the presence
occur via direct hole transfer to glucose bound to TiO2 surface, of N-doped catalysts, the glucose conversion was very similar
due to the strong adsorption of the substrate, as reported in or slightly lower than that measured by using Pt-TiO2, exhibiting
literature.[67–70] Photooxidation of carbohydrates in water was the different N-doped samples a bell shaped trend of the pho-
reported to involve sequential cleavage of formic acid to form tocatalytic efficiency. A noticeable negative effect, instead, was
the shorter aldose and H2. The most active samples for H2 pro-
duction where those containing the lowest W percentages.
In Table 3 the glucose conversion and the selectivity to arabi-
nose, erythrose and formic acid after 6 h of HL irradiation are
reported. The behaviour of powders for glucose degradation
observed in the presence of W-doped catalyst, being the lowest
value obtained by using the Pt-TiO2-W0.5 catalyst. By adding N,
the selectivity to arabinose and formic acid was higher than
that found in the presence of the Pt-TiO2 samples for all of
the dopant percentages, whilst a bell shaped behaviour was
was similar to that observed under UV light irradiation and the observed by increasing the W dopant amount. The selectivity
same oxidation products were obtained. The results showed to erythrose was low and negligible in the presence of N and
that the photocatalytic glucose degradation mechanism is the W, respectively, with the exception of the sample Pt-TiO2-W2.
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
6
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Table 3. Glucose conversion, selectivity to arabinose, erythrose and formic acid and amounts of CO2 and H2 per grams of catalyst after 6 h of HL irradiation.
Sample
Xglucose
Sarabinose
Serythrose
Sformic acid
CO2 [μmol g–1
]
H2 [μmol g–1
]
Pt-TiO2
Pt-TiO2-N0.5
Pt-TiO2-N1
62.1
43.7
61.3
51.9
37.4
32.5
34.5
48.1
36.1
35.9
44.0
45.9
54.3
33.5
36.7
41.5
28.9
44.5
20.1
16.4
16.0
4.7
–
–
–
15.8
–
49.9
61.4
61.8
58.4
32.3
28.6
41.5
26.8
68.7
33
18
30
31
85
66
49
65
23
578
491
278
385
708
671
45
Pt-TiO2-N2
Pt-TiO2-W0.25
Pt-TiO2-W0.5
Pt-TiO2-W1
Pt-TiO2-W2
Pt-TiO2-N0.5W0.5
–
79
This behaviour indicates the occurrence of a different glucose tion with respect to the Pt-TiO2 sample was noticed in the pres-
reaction mechanism in the presence of the various photocata- ence of nitrogen whilst an increase of the formation of both
lysts,[22] due to different effects of the foreign species (which is products was observed by using low amounts of tungsten, de-
not easy to fully explain) on the surface properties. The glucose spite the lower glucose conversion (Table 3) compared to that
conversion in the presence of the co-doped sample was similar obtained with the N-doped samples. The highest W amounts
to that observed in the presence of the Pt-TiO2-W samples. No- had a detrimental effect on the phototocatalytic H2 production,
tably, no improvement was noticed with respect to the Pt-TiO2 being the latter negligible and equal to 708 μmol g–1 by using
sample.
In Figure 11 the amounts of H2 and CO2 after 6 h of HL
irradiation are reported. A negative effect for H2 and CO2 forma-
the Pt-TiO2-W2 and Pt-TiO2-W0.25 samples, respectively. H2 evo-
lution was low also when the co-doped Pt-TiO2-N0.5W0.5 cata-
lyst was employed. By comparing the amounts of CO2 produced
under UV irradiation with those obtained under HL irradiation,
in the latter a general more significant mineralization was ob-
tained with a maximum in the presence of Pt-TiO2-W0.25 sam-
ple. The finding that the activity of the co-doped sample was
not higher than that of the corresponding single doped sam-
ples, indicates that there was not a synergistic effect between
the two dopant species, and probably the high defects number
favoured the e–/h+ recombination.
In order the reduction of H+ to H2 take place, it is necessary
that the conduction band level of the photocatalyst is more
negative than the potential of the H+/H2 couple (EH+/H2 = 0 V
vs. NHE at pH = 0) (Figure 12). Generally, the TiO2 rutile CB
edge has a slight negative value,[71] and it is reported that the
presence of N in TiO2 causes a VB shift towards less positive
values whilst the incorporation of W induces a CB shift towards
less negative values.[66] These considerations could justify the
drop in H2 production by using the W-doped samples for the
highest metal amounts. It is worth noticing that the value of
Figure 11. CO2 and H2 amount per gram of catalyst after 6 h of HL irradiation.
The error of analysis is less than 5.
Figure 12. Photocatalytic hypothesized mechanism of glucose oxidation and
H2 production.
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
7
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
the edge of the conduction band progressively moves to less
negative values as the amount of tungsten increases, reaching
values very close to the hydrogen reduction potential. In
Table 4 the energy values of the conduction band (ECB) and
valence band (EVB) edges, calculated in accordance with Xu and
Schoonen,[72] are reported. The values were calculated by the
empirical Equation (1) and Equation (2):[73]
ECB = ꢀ – Ee – 0.5 Eg
(1)
EVB = ECB + Eg
(2)
Table 4. Energy values of the conduction band (ECB) and valence band (EVB
)
edges.
Sample
ECB [eV]
EVB [eV]
Pt-TiO2-W0.25
Pt-TiO2-W0.5
Pt-TiO2-W1
–0.29
–0.24
–0.12
–0.09
2.97
2.92
2.80
2.77
Pt-TiO2-W2
where Eg is the band gap, Ee is the energy of free electrons vs.
hydrogen (4.5 eV), and ꢀ is the electronegativity of the semicon-
ductor, calculated as the geometric mean of Mulliken's electro-
negativities of the constituent atoms. For TiO2 ꢀ is 5.84 eV.[72]
Even if absolute values cannot be obtained by means of this
method because the structural factors are not taken into ac-
count, it can provide a rough estimation and a trend of the
relative energy of CB and VB vs. normal hydrogen electrode
(NHE). By increasing the W amount, a progressive decrease of
the CB edge was estimated (Table 4), and for the sample Pt-
TiO2-W2 the value is very close to 0 V. This can justify the inac-
tivity of this sample for H2 production.
Figure 13. Amounts of CO2 and H2 per gram of catalyst under SOL or HL
irradiation in the presence of: Pt-TiO2 (A) and Pt-TiO2-W0.25 (B) samples; (Blue
diamond) CO2 SOL, (Red square) H2 SOL, (Green triangle) CO2 HL, (Violet ball)
H2 HL. The error of analysis is less than 5.
The results found are in accord with those reported in the
literature.[16] Many papers report the H2 production from gluc-
ose photoreforming[16] in the presence of different types of TiO2
doped materials and by using Xe, Hg, UVA, UV LED, and solar
Some of the synthesized samples were also tested under nat- simulating lamps as the light sources. By using a solar light
ural solar light irradiation for 3.5 h. Figure 13 reports the reactiv- simulator, Kondarides et al.[74] observed H2 production rates
ity results obtained by using Pt-TiO2 and Pt-TiO2-W0.25 samples, equal to 2.4 mmol gcat–1 h–1 in the presence of Pt-TiO2 (P25)
chosen as the most representative ones, vs. the cumulative irra- with the complete mineralization of glucose to CO2 and without
diation energy. Both samples were more active under natural the formation of high value-added products. By using a 350 W
solar light irradiation than under HL irradiation, and the in- Xe lamp as the irradiation source, 6.7 mmol gcat–1 h–1 of H2
crease of activity was higher in the presence of the Pt-TiO2- were obtained over Pt/TiO2 nanosheets (Pt 2 %) with exposed
W0.25 sample, being the highest H2 production equal to the {001} facet.[75] Pdshell–Aucore nanoparticles immobilized on
3770 μmol g–1 under natural solar light irradiation (Figure 13B). TiO2 exhibited a high efficiency for H2 production under UV
The above results showed the positive effect of tungsten on irradiation (8.8 mmol gcat–1 h–1).[76] To the best of our knowl-
the H2 formation by using the solar energy.
edge no data about the activity under natural solar light irradia-
tion are reported in literature. In our system the best H2 produc-
tion rates was ca. 1.0 mmol gcat–1 h–1 by using Pt-TiO2-W0.25
under natural solar irradiation.
By comparing the photoactivity of Pt-TiO2 and Pt-TiO2-W0.25
samples under natural solar light irradiation and at the same
cumulative energy value (Table 5), a higher glucose conversion
and H2 and CO2 production can be noticed in the presence of
Some runs were carried out under HL irradiation by using,
tungsten. This finding indicates the beneficial role of W in the instead of glucose, formic acid (initial concentration 1 m
activation of TiO2 for H2 production by using the solar irradia- the sacrificial reagent, due to the simplicity of this molecule
tion. and the direct conversion to CO2 and H2, in accordance with
M) as
Table 5. Glucose conversion (X), selectivity (S) to arabinose, erythrose, formic acid, and amounts of CO2 and H2 per gram of catalyst under natural solar
irradiation at the same cumulative energy value (2500 J).
Sample
Xglucose
Sarabinose
Serytthrose
Sformic acid
CO2 [μmol g–1
]
H2 [μmol g–1
]
Pt-TiO2
Pt-TiO2-W0.25
64.40
81.47
49.96
17.62
25.54
0.00
67.63
13.48
74
135
2218
3734
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
8
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
literature.[77,78] The evaluation of the stoichiometric ratio be- case a decrease of the evolution rate of H2 over time was no-
tween the initial amount of formic acid and formed hydrogen ticed. Nevertheless, it was not possible to rationalize these find-
allowed to indirectly hypothesize the occurrence of water split- ings or to check a mass balance as glucose was not completely
ting. Indeed, the amount of H2 produced was higher than that mineralized, and other valuable products were obtained from
which would have been derived simply from formic acid.
The substrate was completely degraded after 2 h of irradia-
tion; afterwards the CO2 concentration remained constant
whilst the amount of H2 began to decrease. The H2 maximum
production was ca. 1160 μmol (corresponding to 1449 μmol g–1),
almost 1.5 times greater than the formic acid initial molar quan-
tity, whilst the CO2 amount was a little lower than the stoichio-
metric value. This finding can be explained by considering that
a fraction of formed CO2 remained probably dissolved in water
and/or adsorbed on the photocatalyst surface. By considering
the formic acid decomposition (dehydrogenation) reaction[77,78]
according to Equation (3):
its transformation.
3. Conclusions
N and/or W doped Pt-TiO2 samples were used for the anaerobic
glucose photo-conversion in aqueous solution under a halogen
lamp and natural solar light irradiation with the dual purpose
of obtaining high value-added products from the partial oxid-
ation of the substrate and H2 from the photo-reforming process.
Different results were obtained in the presence of the two do-
pant species evidencing a different influence on the properties
of TiO2. The presence of N in the Pt-TiO2 sample generally did
not influence the glucose conversion but increased the selecti-
vity to arabinose and formic acid and decreased the H2 produc-
tion. Tungsten had a negative effect on the substrate conver-
sion and a beneficial role on the H2 evolution, with the excep-
tion of the highest dopant amounts. Moreover, arabinose,
erythrose and formic acid were the main products of the partial
oxidation of glucose when using the N-doped samples, whilst
erythrose was found in the presence of W only for the highest
dopant amount. These findings can be attributed to different
TiO2 surface properties when N and W are present. Moreover,
also a difference in the electronic properties was observed in
the presence of the two different dopants, in particular, N
caused a VB shift towards less positive values whilst W induced
a CB shift towards less negative values. The photocatalysts
showed a good activity for H2 production also under direct so-
lar light irradiation, demonstrating the applicability of this type
of materials under real-life conditions.
HCOOH → CO2 + H2
(3)
The finding that the molar ratio between H2 and CO2 was
higher than 1 and that the H2 amount was higher than that
corresponding to the total mineralization of formic acid, sug-
gests that the produced H2 derived from both formic acid and
water splitting, with the simultaneous formation of O2. More-
over, the decrease of the H2 amount after formic acid disap-
pearance was probably due to the occurrence of the back reac-
tion between H2 and O2 and/or to the Ti4+ reduction by H2.
Probably, the former reaction occurred also during the first
hours of irradiation, but its rate increased by increasing the
quantity of O2 formed and present in the solution. When the
substrate was still present, the amount of H2 that recombined
with oxygen was balanced by that coming from formic acid.
This explains the observed decrease of H2 production reaction
rate by increasing the irradiation time, until an almost constant
value or a decrease of its concentration was reached (Figure 14).
Notably, no production of H2 was observed in the absence of
formic acid, confirming the essential role of the sacrificial
agents in the electron/hole separation. Some of these consider-
ations based on the experimental results could also be ex-
tended to the H2 production from glucose, because also in this
4. Experimental Section
4.1 Photocatalysts Preparation: Bare TiO2 powders were prepared
by adding 10 mL of TiCl4 (Sigma–Aldrich) to 40 mL of distilled water
at room temperature. After ca. 20 min of stirring, the clear solution
was placed in a Teflon-lined stainless steel autoclave at room tem-
perature, and afterwards heated at 100 °C for 48 h. The solid was
recovered by drying at 60 °C, and it was named TiO2. Pt-TiO2 sam-
ples (nominal Pt weight percentage 0.5 %) were obtained by adding
the proper amount of PtCl4 (Sigma–Aldrich) to the TiCl4/H2O solu-
tion prior to the hydrothermal treatment. Pt-Nitrogen, Pt-Tungsten
or Pt-Nitrogen-Tungsten loading were performed under mild condi-
tions: appropriate amounts of NH4Cl and WCl6 were added to the
clear Pt-TiCl4/H2O solution to obtain samples containing different
weight percentages of N and W during the hydrothermal treatment.
The samples were indicated as: Pt-TiO2-N0.5, Pt-TiO2-N1, Pt-TiO2-N2,
Pt-TiO2-W0.25, Pt-TiO2-W0.5, Pt-TiO2-W1, Pt-TiO2-W2, Pt-TiO2-
N0.5W0.5, the figures indicating the weight percentages of N and/
or W.
4.2 Characterization of the Samples: X-ray diffraction (XRD) pat-
terns of the powders were obtained by a PANalytical X′pertPro X-
ray diffractometer with Cu-Kα radiation and 2θ scan rate of 2 °C/
min. The crystalline sizes of the samples were determined by using
the Scherrer equation. The diffuse reflectance spectra (DRS) in the
250–800 nm wavelength range were obtained by using a Shimadzu
Figure 14. Concentration of: (Orange ball) formic acid, (Blue diamond) CO2
and (Green square) H2 vs. time under HL irradiation in the presence Pt-TiO2-
W0.25 sample. The error of analysis is less than 5.
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
9
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
[7] R. Li, Chinese J. Catal. 2017, 38, 5.
UV-2401 PC spectrophotometer with BaSO4 as the reference mate-
rial. Band gap values were determined by plotting the modified
Kubelka–Munk function, [F(R′∞)hν]1/2, vs. the energy of the exciting
light. The specific surface area (SSA) and the pore size distribution
(PSD) of the photocatalysts were determined by nitrogen adsorp-
tion-desorption measurements with a Micromeritics ASAP 2020 ap-
paratus. SSA's were calculated by the BET equation in the p/po
interval 0.05–0.33 while the PSD's were calculated by using the
Barrett Joyner Halenda (BJH) methods.
[8] K. Maeda, K. Domen, J. Phys. Chem. Lett. 2010, 1, 2655.
[9] R. Kothari, D. Buddhi, R. L. Sawhney, Renewable Sustainable Energy Rev.
2008, 12, 553.
[10] J. Zhu, M. Zäch, Curr. Opin. Colloid Interface Sci. 2009, 14, 260.
[11] H. Bahruji, M. Bowker, P. R. Davies, L. S. Al-Mazroai, A. Dickinson, J.
Greaves, D. James, L. Millard, F. Pedrono, J. Photochem. Photobiol. A 2010,
216, 115.
[12] M. Ni, M. K. H. Leung, D. Y. C. Leung, K. Sumathy, Renewable Sustainable
Energy Rev. 2007, 11, 401.
[13] D. I. Kondarides, V. M. Daskalaki, A. Patsoura, X. E. Verykios, Catal. Lett.
2008, 122, 26.
[14] M. de Oliveira Melo, L. Almeida Silva, J. Braz. Chem. Soc. 2011, 22, 1399.
[15] X. Fu, J. Long, X. Wang, D. Y. C. Leung, Z. Ding, L. Wu, Z. Zhang, Z. Li, X.
Fu, Int. J. Hydrogen Energy 2008, 33, 6484.
Transmission electron microscopy (TEM) measurements were car-
ried out by a JEOL (Japan) JEM-2100 electron microscope operating
at 200 KV, while HR-TEM images SAED (Selected Area Electron Dif-
fraction) patterns were obtained by a Gatan (USA) MSC camera.
Samples were prepared by dispersing them in 2 mL of deionized
water and by sonicating them for 5 minutes. A drop of each disper-
sion was spread on a copper holey carbon coated grid and dried
overnight prior TEM analysis. Particles size and atomic layers spac-
ing were measured by Gatan (USA) Digital Micrograph software.
[16] A. Puga, Coord. Chem. Rev. 2016, 315, 1.
[17] M. F. Kuehnel, E. Reisner, Angew. Chem. Int. Ed. 2018, 57, 3290.
[18] J. C. Colmenares, A. Magdziarz, A. Bielejewska, Bioresour. Technol. 2011,
102, 11254.
[19] R. Chong, J. Li, Y. Ma, B. Zhang, H. Han, C. Li, J. Catal. 2014, 314, 101.
[20] M. Bellardita, E. I. García-López, G. Marcì, B. Megna, F. R. Pomilla, L. Palmi-
sano, RSC Adv. 2015, 5, 59037.
[21] W. Deng, Q. Zhang, Y. Wang, Catal. Today 2014, 234, 31.
[22] M. Bellardita, E. García-López, G. Marcì, L. Palmisano, Int. J. Hydrogen En-
ergy 2016, 41, 5934.
[23] T. Montini, M. Monai, A. Beltram, I. Romero-Ocaña, P. Fornasiero, Mater.
Sci. Semicon. Proc. 2016, 42, 122.
[24] H. Dong, G. Zeng, L. Tang, C. Fan, C. Zhang, X. He, Y. He, Water Res. 2015,
79, 128.
[25] D. Dvoranová, V. Brezová, M. Mazúr, M. A. Malati, Appl. Catal. B 2002, 37,
91.
[26] A. Di Paola, E. García-López, S. Ikeda, G. Marcı`, B. Ohtani, L. Palmisano,
Catal. Today 2002, 75, 87.
[27] J. Choi, H. Park, M. R. Hoffmann, J. Phys. Chem. C 2010, 114, 783.
[28] L. Gomathi Devi, R. Kavitha, Appl. Catal. B 2013, 140–141, 559.
[29] R. Asahi, T. Morikawa, H. Irie, T. Ohwaki, Chem. Rev. 2014, 114, 9824.
[30] R. Amadelli, L. Samiolo, M. Borsa, M. Bellardita, L. Palmisano, Catal. Today
2013, 206, 19.
[31] J. Belošević-Cavor, K. Batalović, V. Koteski, J. Radaković, C. M. Rangel, Int.
J. Hydrogen Energy 2015, 40, 9696.
[32] B. Choudhury, B. Borah, A. Choudhury, Mater. Sci. Eng. B 2013, 178, 239.
[33] A. Kubacka, B. Bachiller-Baeza, G. Colón, M. Fernández-García, Appl. Catal.
B 2010, 93, 274.
[34] W. M. Campbell, A. K. Burrell, D. L. Officer, K. W. Jolley, Coord. Chem. Rev.
2004, 248, 1363.
[35] T. Wu, G. Liu, J. Zhao, H. Hidaka, N. Serpone, J. Phys. Chem. B 1998, 102,
5845.
[36] R. Fiorenza, M. Bellardita, S. Scirè, L. Palmisano, Catal. Today https://
doi.org/ttps://doi.org/10.1016/j.cattod.2017.12.011, 2018.
[37] G. Longo, F. Fresno, S. Gross, U. L. Štangar, Environ. Sci. Pollut. Res. 2014,
21, 11189.
[38] D. P. Kumar, M. V. Shankar, M. M. Kumari, G. Sadanandam, B. Srinivas, V.
Durgakumari, Chem. Commun. 2013, 49, 9443.
4.3 Photocatalytic Activity: Some preliminary runs were carried
out under UV light (by using a 125 W medium pressure Hg lamp)
to test the efficiency of the catalysts. The lamp radiant power, meas-
ured by a radiometer Delta Ohm DO9721, was ca. 120 W m–2 in
the range 315–400 nm. Successively, all the prepared samples were
tested in a 1040 mL Pyrex cylindrical reactor illuminated by a 150 W
halogen lamp axially immersed within the photoreactor which was
filled with 800 mL of 1 m
M glucose solution. The lamp radiant
power was ca. 2100 W m–2 in the 450–750 nm range, and
17 W m–2 in the range 315–400 nm. N2 was bubbled into suspen-
sions for ca. 0.5 h under dark to remove O2 from the solution, then
the reactor was sealed and the lamp switched on for 6 h. The best
photocatalysts were tested also under natural solar light irradiation
by using a closed batch Pyrex reactor whose volume was 250 mL,
filled with 100 mL of glucose solution. In all cases, the amount of
catalyst used was 1.0 g L–1 of suspension. The runs under natural
solar light irradiation lasted 3.5 h. Glucose was used both as sacrifi-
cial agent for H2 production and as reagent to obtain high value
chemicals from its partial oxidation. For the sake of comparison
some experiments were performed by using formic acid instead of
glucose. The concentrations of glucose, photo-products and formic
acid were measured by a Thermo Scientific Dionex UltiMate 3000
HPLC equipped with a Diode Array and a refractive index detectors
equipped with a REZEK ROA Organic acid H+ column. An aqueous
2.5 m
M H2SO4 solution was used as the eluent at a flow rate of
0.6 mL min–1. The gaseous H2 and CO2 species were analyzed by
a HP 6890 Series GC System equipped with a Supelco GC 60/80
CarboxenTM-1000 packed column and a thermal conductivity de-
tector (TCD). Helium was used as the carrier gas. The error of analy-
sis was less than 5 %.
[39] L. Chen, X. Zhou, B. Jin, J. Luo, X. Xu, L. Zhang, Y. Hong, Int. J. Hydrogen
Energy 2016, 41, 7292.
[40] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, Y. Taga, Science 2001, 293, 269.
[41] S. A. Ansari, M. M. Khan, M. O. Ansari, M. H. Cho, New J. Chem. 2016, 40,
3000.
[42] M. Bellardita, M. Addamo, A. Di Paola, L. Palmisano, A. M. Venezia, Phys.
Chem. Chem. Phys. 2009, 11, 4084.
Keywords: Photocatalysis · Doping · Titanium dioxide ·
Glucose reforming · Hydrogen evolution · Oxidation
[43] H. Irie, Y. Watanabe, K. Hashimoto, J. Phys. Chem. B 2003, 107, 5483.
[44] N. Serpone, J. Phys. Chem. B 2006, 110, 24287.
[45] M. Ilie, B. Cojocaru, V. I. Parvulescu, H. Garcia, Int. J. Hydrogen Energy
2011, 36, 15509.
[46] Y. Wang, L. Zhu, N. Ba, F. Gao, H. Xie, Mater. Res. Bull. 2017, 86, 268.
[47] Y. He, Z. Wu, L. Fu, C. Li, Y. Miao, L. Cao, H. Fan, B. Zou, Chem. Mater.
2003, 15, 4039.
[48] O. Lorret, D. Francova, G. Waldner, N. Stelzer, Appl. Catal. B 2009, 91, 39.
[49] H. Choi, D. Shin, B. C. Yeo, T. Song, S. S. Han, N. Park, S. Kim, ACS Catal.
2016, 6, 2745.
[1] J. D. Holladay, J. Hu, D. L. King, Y. Wang, Catal. Today 2009, 139, 244.
[2] S. E. Hosseini, M. A. Wahid, Renewable Sustainable Energy Rev. 2016, 57,
850.
[3] K. Mazloomi, C. Gomes, Renewable Sustainable Energy Rev. 2012, 16,
3024.
[4] N. Florin, A. Harris, Environmentalist 2007, 27, 207.
[5] R. M. Navarro, M. C. Sánchez-Sánchez, M. C. Alvarez-Galvan, F. del Valle,
J. L. G. Fierro, Energy Environ. Sci. 2009, 2, 35.
[6] N. Meng, D. Y. C. Leung, M. K. H. Leung, K. Sumathy, Fuel Process. Technol.
2006, 87, 461.
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
10
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
[50]
[51]
[52]
[53]
[54]
[55]
[56]
[57]
[67] G. Kim, S.-H. Lee, W. Choi, Appl. Catal. B 2015, 162, 463.
[68] K. E. Sanwald, T. F. Berto, W. Eisenreich, O. Y. Gutiérrez, J. A. Lercher, J.
Catal. 2016, 344, 806.
[69] I. A. Shkrob, T. W. Marin, S. D. Chemerisov, M. D. Sevilla, J. Phys. Chem. C
2011, 115, 4642.
[70] M.-H. Du, J. Feng, S. B. Zhang, Phys. Rev. Lett. 2007, 98, 066102.
[71] A. Di Paola, M. Bellardita, R. Ceccato, L. Palmisano, F. Parrino, J. Phys.
Chem. C 2009, 113, 15166.
[72] Y. Xu, M. A. A. Schoonen, Am. Mineral. 2000, 85, 543.
[73] F. Tavakoli, A. Badiei, G. Mohammadi Ziarani, S. Tarighi, Int. J. Environ.
Res. 2017, 11, 217.
[74] D. I. Kondarides, A. Patsoura, X. E. Verykios, J. Adv. Oxid. Technol. 2010,
13, 116.
[75] J. Yu, L. Qi, M. Jaroniec, J. Phys. Chem. C 2010, 114, 13118.
[76] R. Su, R. Tiruvalam, A. J. Logsdail, Q. He, C. A. Downing, M. T. Jensen, N.
Dimitratos, L. Kesavan, P. P. Wells, R. Bechstein, H. H. Jensen, S. Wendt,
C. R. A. Catlow, C. J. Kiely, G. J. Hutchings, F. Besenbacher, ACS Nano
2014, 8, 3490.
S. S. Thind, G. Wu, A. Chen, Appl. Catal. B 2012, 111–112, 38.
S. R. Gul, M. Khan, Z. Yi, B. Wu, Materials 2018, 11, 313.
A. Siddiqa, D. Masih, D. Anjum, M. Siddiq, J. Environ. Sci. 2015, 37, 100.
J. J. Brancho, B. M. Bartlett, Chem. Mater. 2015, 27, 7207.
A. Kubacka, G. Colón, M. Fernández-García, Appl. Catal. B 2010, 95, 238.
Y. F. Shen, T. Y. Xiong, T. F. Li, K. Yang, Appl. Catal. B 2008, 83, 177.
J. X. Li, J. H. Xu, W.-L. Dai, H. Li, K. Fan, Appl. Catal. B 2008, 83, 233.
M. Zhang, J. Wu, D. D. Lu, J. Yang, Int. J. Photoenergy 2013, 2013, ID
471674.
[58] A. Corma, S. Iborra, A. Velty, Chem. Rev. 2007, 107, 2411.
[59] J. C. Colmenares, R. Luque, Chem. Soc. Rev. 2014, 43, 765.
[60] M. Bellardita, M. Addamo, A. Di Paola, L. Palmisano, Chem. Phys. 2007,
339, 94.
[61] K. S. W. Sing, D. H. Everett, R. A. W. Haul, L. Moscou, R. A. Pierotti, J.
Rouquerol, T. Siemieniewska, Pure Appl. Chem. 1985, 57, 603. 1685
[62] B. Sun, G. Zhou, Y. Zhang, R. Liu, T. Li, Chem. Eng. J. 2015, 264, 125.
[63] E. M. Samsudin, S. B. A. Hamid, Appl. Surf. Sci. 2017, 391, 326.
[64] T. Tachikawa, Y. Takai, S. Tojo, M. Fujitsuka, H. Irie, K. Hashimoto, T. Ma-
jima, J. Phys. Chem. B 2006, 110, 13158.
[77] M. Wu, M. Zhang, T. Lv, M. Guo, J. Li, C. A. Okonkwo, Q. Liu, L. Jia, Appl.
Catal. A 2017, 547, 96.
[78] S. Cao, Y. Chen, H. Wang, J. Chen, X. Shi, H. Li, P. Cheng, X. Liu, M. Liu, L.
Piao, Joule 2018, 2, 549.
[65] F. Riboni, L. G. Bettini, D. W. Bahnemannd, E. Selli, Catal. Today 2013, 209,
28.
[66] W.-J. Yin, H. Tang, S.-H. Wei, M. M. Al-Jassim, J. Turner, Y. Yan, Phys. Rev.
B 2010, 82, 045106.
Received: May 28, 2018
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
11
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Aqueous Glucose Reforming
H2 was produced with use of natural
solar light irradiation by aqueous gluc-
ose reforming under green conditions
with tungsten and nitrogen doped
Pt-TiO2 samples. Also, high value-
added products were obtained from
the partial oxidation of glucose. The
highest H2 production rate (ca.
1.0 mmol gcat–1 h–1) was observed in
the presence of the Pt-TiO2-W0.25
sample.
M. Bellardita,* E. I. García-López,
G. Marcì, G. Nasillo,
L. Palmisano* ................................... 1–12
Photocatalytic Solar Light H2 Pro-
duction by Aqueous Glucose Re-
forming
DOI: 10.1002/ejic.201800663
Eur. J. Inorg. Chem. 0000, 0–0
www.eurjic.org
12
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim