The synergy between the CsPbBr3nanoparticle surface and the organic ligand becomes manifest in a demanding carbon-carbon coupling reaction

Article abstract of DOI:10.1039/d0cc01339k

We demonstrate here the suitability of CsPbBr₃nanoparticles as photosensitizers for a demanding photoredox catalytic homo- and cross-coupling of alkyl bromides at room temperature by merely using visible light and an electron donor, thanks to the cooperative action between the nanoparticle surface and organic capping.

Full text of DOI:10.1039/d0cc01339k

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The synergy between the CsPbBr nanoparticle
3
surface and the organic ligand becomes manifest
in a demanding carbon–carbon coupling
reaction†
Cite this:DOI: 10.1039/d0cc01339k
Received 20th February 2020,
Accepted 25th March 2020
a
b
a
Ignacio Rosa-Pardo,
Carla Casadevall,
Luciana Schmidt,
‡
DOI: 10.1039/d0cc01339k
b
a
bc
Miguel Claros,
Julia Perez-Prieto
Raquel E. Galian, * Julio Lloret-Fillol
*
and
a
rsc.li/chemcomm
*
´
We demonstrate here the suitability of CsPbBr
photosensitizers for a demanding photoredox catalytic homo- and quantum yield (QYPL) of up to 100%
cross-coupling of alkyl bromides at room temperature by merely any electronic passivation with an inorganic material that has a
using visible light and an electron donor, thanks to the cooperative wider bandgap. The tolerance of APbX perovskites is attributed
action between the nanoparticle surface and organic capping. to the formation of defect states near the band edges.
Moreover, they can present considerable luminescence as bare
3
nanoparticles as perovskite NCs can be synthesized with a photoluminescence
1
6–18
without the need of
3
1
9–21
2
2
3
Lead halide perovskites with the formula APbX , where A is a nanoparticles. On the contrary, in common semiconductors,
+
+
small-sized monocation (such as CH NH , Cs ) and X is a the intrinsic defects are deeply located in the middle of the gap
3
3
À
À
À
halide anion (Cl Br , I ), present a three-dimensional inorganic and, consequently, they can trap the carriers generated after
2
3
framework consisting of corner-sharing PbX6 octahedra and excitation of the NCs, reducing the QYPL
small-sized cations in the voids between them (Fig. S1, ESI†). sensitized reactions, APbX NCs have a higher conduction band
These are promising semiconductors for low-cost solar energy (CB) edge, but also a higher valence band edge
conversion, due to their effectiveness in charge separation as well APbX NCs can be more effective photosensitizers for reduction
as hole and electron transport. These qualities are also essen- of organic substrates, while CdS, CdSe and TiO
tial for their application in photocatalysis, since the photogener- more effective for oxidation of organic substrates.
.
In terms of photo-
3
2
4–26
therefore,
3
1–4
27–30
2
can be
Y. Yan
3
1–35
ated charges are trapped at different surface sites and concerted et al. have recently reported on the potential of the CsPbBr NCs
3
6
,7
interfacial electron transfer reactions with electron acceptor and as photosensitizers for reductive Csp
electron donor substrates can occur if their reduction potentials are strating the capacity of these perovskites to promote a-alkylation
within the bandgap. The performance of APbX in photovoltaics has of aldehydes with a-bromoacetophenones. This process requires
proved to be superior to that of II–VI semiconductors, and this can the presence of an organic co-catalyst (bis(2-chloroethyl)amine
3
–Csp
3
formation, demon-
3
5
6
–10
also apply to light-induced catalytic organic transformations.
APbX
perovskite nanocrystals (NCs) share some similarities of the acetophenone was selectively achieved by using (5S)-(À)-2,2,3-
with CdSe and CdTe quantum dots, in particular, a strong trimethyl-5-benzyl-4-imidazolidinone as the co-catalyst.
absorption and a wide spectrum extending well into the visible Taking into account the CB edge energy of CsPbBr and the
range, a narrow emission peak and electronic properties tune- redox potential of a-bromoacetophenone of about À0.96 V and
hydrochloride) and a base (2,6-lutidine). The C–C homocoupling
3
7
3
11
1
1–15
36,37
able with the composition and size of the NCs.
However, À0.25 V (vs. SHE),
respectively, the photoreduction of a-bromo-
contrary to them and due to their defect tolerance, core APbX
3
acetophenone is thermodynamically exergonic, due to the fact that
the excited state of the perovskite is a potent reductant and would
enable the heterolytic cleavage of the C–Br bond.
A more demanding process is that of the photoredox
a-benzylation of aldehydes with a less activated C–Br bond,
a
Institute of Molecular Science (ICMol), University of Valencia c/Catedr a´ tico Jos ´e
Beltr a´ n 2, Paterna, E46980 Valencia, Spain. E-mail: julia.perez@uv.es
b
Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of
Science and Technology, Avinguda Pa ¨ı sos Catalans 16, 43007 Tarragona, Spain
such as that of benzyl bromide with a reduction potential, E1/2,
c
38
Catalan Institution for Research and Advanced Studies (ICREA) Passeig Llu ¨ı s
of À1.61 V vs. SHE in CH CN. In fact, the strong reductant
3
Companys, 23, 08010, Barcelona, Spain
Ir(ppy) excited state, *Ir(ppy) , (E
1/2
of À1.49 V vs. SHE in
3
3
†
Electronic supplementary information (ESI) available: Further spectra, charac-
terization and data analysis. See DOI: 10.1039/d0cc01339k
Present address: INFIQC (UNC-CONICET), Dpto. Qu ´ı mica Org ´a nica, Facultad
3
9
3
CH CN) fails to promote this process.
These results motivated our study of the reductive C–C coupling
‡
de Ciencias Qu ´ı micas, X5000HUA C o´ rdoba, Argentina.
of benzyl bromides by using CsPbBr
NCs as a photocatalyst and
3
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a tertiary amine as the electron donor (ED), bearing in mind that Table 1 Homo- and cross-coupling of benzyl bromides photocatalyzed
a
3
by colloidal CsPbBr perovskite
the encapsulating effect of a NC lipophilic organic capping could
approach the substrate and the ED to the perovskite surface, thus
assisting the process and improving the photocatalysis.
Here is reported for the first time that the combination of
visible light irradiation, DIPEA (N,N-diisopropylethylamine), and
colloidal CsPbBr enables the photocatalytic single-electron trans-
3
fer to benzyl bromides, eventually leading to the benzyl radical and
finally to the C–C homocoupling products. Turnover numbers
3
(TON, moles of substrate transformed/moles of CsPbBr NCs)
higher than 17 500 were obtained. The formation of cross-
coupling products was also tested by using two different benzyl
bromides in the reaction.
First, colloidal CsPbBr
3
capped with dodecylamine (DDA)
was prepared by the ligand assisted reprecipitation technique
40
with some modifications (Fig. S1, ESI†). The colloid concentration
was estimated as 3.6 mM by using the molar coefficient reported
6
À1
À1
for CsPbBr
3
nanocubes of 11 nm (e = 3.5 Â 10 M cm at
41
l = 510 nm). This material presented a major absorption peak
at 500 nm and PL maximum at 510 nm in toluene (full width at
half maximum, FWHM, of 20 nm, Fig. S2, ESI†), average PL
lifetime (tav) of 34 ns and QYPL of 31%.
The CsPbBr colloid was first evaluated as photocatalyst for
the coupling of benzyl bromide 1a to yield 1b, using an in-house
4
0
a
3
General conditions of the reaction: CsPbBr (1.44 mM), total substrate
3
(
2
34 mM; 17 mM of each substrate in the cross-coupling assays),
0 equiv. of DIPEA, solvent (toluene, total volume: 1 mL), irradiation
developed 48-well parallel photoreactor with the capacity to control at 447 Æ 20 nm during 20 h (48 h when using two different
2
p-substituted benzyl bromides) at 30 1C under N , conversion 100%.
c
the temperature and the radiation of the reactions (Fig. S3, bottom,
ESI†). Two solvents of different polarity (toluene and ethyl acetate)
b
The results are average of at least 2 duplicates. The values reported
1
are GC-FID/ H-NMR yields. Results in parenthesis represent isolated
d
and three EDs (trimethylamine, TEA; tri-phenylphosphine, PPh3; yields from 3 reactions at 30 1C irradiated for 60 h. DIPEA (10 equiv.).
e
f
Two hours soft stirring in the shaker prior irradiation. Cross-
coupling obtained from run 8–10.
DIPEA in 20, 10 and 3 equiv.) were tested. The mixture containing
the perovskite (1.44 mM), 1a (34 mM) and the ED was irradiated
with visible light (LED 447 Æ 20 nm) at 30 1C for 20 h under
nitrogen while soft stirred using a shaker (see details in ESI†). p-substituent of the benzyl bromide and decreased in the
t
Screening of reaction conditions was first carried out; the yields following order: H, Bu, OMe 4 Cl 4 Br. Considering the
were calculated by Gas Chromatography-Flame Ionization detector concentration of NCs in solution, a TON up to 17 500 was
(GC-FID) analysis of the reaction crude using biphenyl as internal estimated, illustrating these NCs are self-sufficient, in the sense
standard (see Table S1 in ESI† for further details). DIPEA was the that they do not require a co-catalyst, and are highly active to
best ED of the tested ones. In the case of using TEA and PPh , the engage the demanding catalytic transformations (see below).
3
formation of some white precipitate was seen with the naked eye.
This is consistent with the formation of the corresponding registered in toluene/CH
The reduction of the benzyl bromides used in this study was
CN (85 : 15, v : v) and they proved to be
3
quaternary salts (see Fig. S4, ESI†), whose precipitation may irreversible (see Fig. S14–S19, ESI†), with an onset potential at
partly justify their lower efficacy as ED. Therefore, DIPEA was À1.50 V vs. SHE. DFT calculations for the one-electron reduction
selected as the ED for the rest of the study. Table 1 shows the of benzyl bromide were in agreement with a found redox potential
results of the photocatalyzed homo- and cross-coupling of of À1.44 vs. SHE (see computational studies and Fig. S20 in ESI†).
benzyl bromides in toluene; the values reported are GC-FID These values are significantly lower than the CsPbBr3 redox
yields and/or isolated yields. Results in parenthesis represent potential considering the CB edge energy (À0.96 V vs. SHE),
isolated yields from 3 reactions irradiated at 447 nm (LED 1 W) and therefore the formation of the benzyl radical is thermo-
for 60 h at 30 1C using an in-house developed 25-well parallel dynamically disfavoured. This is also true for the rest of the
4
2
photoreactor (Fig. S3, top, ESI†). In general, the chromato- benzyl bromide series.
1
gram and H-NMR spectrum analysed after the reaction were
Then, we studied electronic effects by evaluating the reaction
clean, showing only unreacted starting material, coupling pro- between different p-substituted benzyl bromides using the optimized
ducts and internal standard (see Fig. S5–S13, ESI†). The mass conditions: CsPbBr3 (1.44 mM), DIPEA (20 equiv.), toluene as
loss could be attributed to the formation of the dehalogenation solvent, irradiation at 447 nm of the as-prepared mixture at
product, which for 1a is toluene.
30 1C for 48 h under nitrogen. Remarkably, homocoupling
Formation of the homocoupling product 1b was successful; product 2b was produced selectively vs. 1b (run 8, Table 1),
the yield decreased slightly when using 10 instead of 20 equiv. and there was some selectivity in the production of products 1b
of DIPEA. The product yield depended on the nature of the and 3b vs. the cross-coupling product 7 (run 9, Table 1). A nearly
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statistical mixture of products was obtained in the reaction of 2a the ED and the reductive state of the perovskite was able to reduce
and 3a (run 10, Table 1).
the benzyl bromide to give the benzylic radical.
The small selectivity in the cross-coupling products observed
The HOMO energy level of trialkyl amines is reported at
4
3
for all cases together with the thermodynamically disfavoured À5.76 eV, i.e., it is more positive than that of the perovskite
1
1,44
formation of the benzyl radical intermediate is puzzling. How- valence band maximum (between À5.85 eV and À6.4 eV).
ever, it could be rationalized by substrate pre-concentration and, Consequently, there is a driving force for the hole transfer (between
consequently, a high concentration of the generated radical B0.1 and 0.6 eV) and, therefore, for the charge separation. In
anions in the nanoparticle surface (see discussion in ESI,† principle, generation of the benzyl bromide anion radical is not
Section 6), favoured by the van der Waals interactions between thermodynamically favourable, but the interaction between the
the alkyl chains of the capping groups and the substrates.
benzyl bromide, preconcentrated within the organic capping,
4
5,46,47
Therefore, a very high substrate concentration could build and with the NC surface
would facilitate the electron
enough benzyl bromide radical to facilitate the exergonic C–C transfer process, eventually leading to the coupling products
bond formation driving the reaction forward but at expenses of (Fig. 1). The recyclability of the perovskite was also tested using
selectivity (Fig. 1). Control experiments without either perov- 1a as the substrate. After the first catalytic run reported in
skite NCs or light, under otherwise same conditions, corroborated Table 1, the perovskite was recovered by centrifugation and
that C–C products did not form for any of the substrates washed with toluene to remove unreacted organic substrate and
included in Table 1 (experiments performed at least twice, formed products. The recovered perovskite was used in a second
Table S1, ESI†).
run again adding DIPEA (20 equiv.), the substrate and toluene,
To gain some insight into the mechanism, we monitored the and irradiating for 20 h. The yield of 1b significantly dropped to
UV-Vis spectrum of a solution containing CsPbBr under different 3%. Further irradiation up to 60 h only produced an increase to
3
conditions. First, a fresh solution of the perovskite in toluene while 9%. The absorption spectrum of the sample showed a consider-
irradiating with the LED showed the appearance of two negative able increase of the scattering and the appearance of an
bands at 450 nm and at 510 nm assigned to scattered radiation excitonic peak at about 523 nm (compare Fig. S24a and b).
and emission of the perovskite, respectively (Fig. S21, ESI†). The The emission peak of the perovskite shifted from 517 nm to
addition of benzyl bromide to this solution under irradiation did 523 nm and the emission efficiency, as well as the emission
not change significantly the spectrum, thus suggesting that the lifetime, decreased (QYPL 14% and tav 21 ns). The addition of
À1
excited state of the perovskite cannot directly activate the benzyl DDA (up to 70 mL from a stock solution of 5 mg mL ) to this
bromide. Accordingly, blank experiments showed the recovery of sample led to (i) a decrease in the sample scattering and a blue
the benzyl bromide after irradiation. However, the addition of the shift of the excitonic peak to 515 nm and (ii) a high recovery of
ED to this solution led to a partial reduction of the emission of the perovskite emission and a peak shift to 519 nm (Fig. S24 c,
the band at 510 nm after 200 s (Fig. S22, ESI†). Interestingly, ESI†). Moreover, transmission electron microscopy (TEM) images
the reduction of the emission of the band at 510 nm is practically of the recovered perovskite showed it consisted of microsized
3
quantitative if the ED is added to a fresh CsPbBr solution in the perovskites together with an increase of perovskite NCs number
absence of the benzyl bromide (Fig. S23, ESI†). All together (Fig. S24 d, ESI†). Note that the yield of the coupling product
suggested that the CsPbBr perovskite is reductively quenched by decreased significantly when the reaction mixture was softly
3
Fig. 1 Schematic representation of (a) the cooperative action between the NC surface and the capping for the catalysed coupling reaction and (b) the
processes occurring after Vis-excitation of the CsPbBr
within the capping.
3
in the presence of the benzyl halide (electron acceptor) and DIPEA (electron donor) encapsulated
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stirred in the shaker for two hours before irradiation, (run 3, 15 S. Gonzalez-Carrero, R. E. Galian and J. P ´e rez-Prieto, Opt. Express,
2
016, 24, A285–A301.
Table 1); this is consisting with ligand removal from the NC surface
by DIPEA. To determine if the low performance of the isolated
1
6 S. Gonzalez-Carrero, L. Franc ´e s-Soriano, M. Gonz ´a lez-B ´e jar, S. Agouram,
R. E. Galian and J. P ´e rez-Prieto, Small, 2016, 12, 5245–5250.
perovskite was due to the removal of the ligands at the NC surface 17 S. Gonz ´a lez-Carrero, L. Mart ´ı nez-Sarti, M. Sessolo, R. E. Galian and
J. P ´e rez-Prieto, J. Mater. Chem. C, 2018, 6, 6771–6777.
8 F. Zhang, H. Zhong, C. Chen, X.-G. Wu, X. Hu, H. Huang, J. Han,
B. Zou and Y. Dong, ACS Nano, 2015, 9, 4533–4542.
due to the washing treatment, the reaction was repeated under the
same conditions and then, without work-up, we added again
1
substrate (1 equiv.) and the mixture was shaken for additional 19 V. S. Chirvony, S. Gonz ´a lez-Carrero, I. Su ´a rez, R. E. Galian, M. Sessolo,
H. J. Bolink, J. P. Mart ´ı nez-Pastor and J. P ´e rez-Prieto, J. Phys. Chem. C,
2
0 h under the otherwise same conditions. This experiment was
2017, 121, 13381–13390.
repeated twice; the conversion of 1a was about 66% and 1b was
obtained in a 45% yield (average values of two duplicates).
2
2
0 D. Meggiolaro, S. G. Motti, E. Mosconi, A. J. Barker, J. Ball, C. Andrea
Riccardo Perini, F. Deschler, A. Petrozza and F. De Angelis, Energy
Environ. Sci., 2018, 11, 702–713.
To sum up, for the first time it is demonstrated that colloidal
CsPbBr3 perovskite NCs are suitable as photosensitizers for
photoredox catalytic homo-/cross-coupling of benzyl bromides
at room temperature with TON up to 17 500 by merely using Vis
light and an electron donor, such as DIPEA. This is a clear
example of the potentiality of these perovskites in light-induced
catalytic transformations, where the synergy between the ligand
and the NC surface plays a crucial role. These results broaden
the applicability of these materials in photocatalysis.
1 V. Adinolfi, M. Yuan, R. Comin, E. S. Thibau, D. Shi, M. I.
Saidaminov, P. Kanjanaboos, D. Kopilovic, S. Hoogland, Z.-H. Lu,
O. M. Bakr and E. H. Sargent, Adv. Mater., 2016, 28, 3406–3410.
2 S. Gonzalez-Carrero, L. C. Schmidt, I. Rosa-Pardo, L. Mart ´ı nez-Sarti,
M. Sessolo, R. E. Galian and J. P ´e rez-Prieto, ACS Omega, 2018, 3, 1298–1303.
3 R. E. Brandt, J. R. Poindexter, P. Gorai, R. C. Kurchin, R. L. Z. Hoye,
2
2
L. Nienhaus, M. W. B. Wilson, J. A. Polizzotti, R. Sereika, R. Z
ˇaltauskas,
L. C. Lee, J. L. MacManus-Driscoll, M. Bawendi, V. Stevanovi ´c and
T. Buonassisi, Chem. Mater., 2017, 29, 4667–4674.
4 Q. Lu, Y. Yu, Q. Ma, B. Chen and H. Zhang, Adv. Mater., 2016, 28,
1917–1933.
5 J. Chen, C. Dong, H. Idriss, O. F. Mohammed and O. M. Bakr, Adv.
Energy Mater., 2019, 1902433.
2
2
2
2
2
2
3
Thanks to MINECO (CTQ2017-82711-P, CTQ2016-80038-R,
FPU17/05564 (I. R.-P.), FPU14/02550 (C. C.), partially co-financed
with FEDER funds), GV (PROMETEO/2019/080 and IDIFEDER/2018/
3
6 The conduction band edge of CsPbBr nanocrystals (11 nm size) is
À3.35 eV versus vacuum, see ref. 11.
7 G. F. Samu, R. A. Scheidt, P. V. Kamat and C. Jan ´a ky, Chem. Mater.,
064), ICIQ Foundation, ERF for project FP7-PEOPLE-2010-ERG-
2018, 30, 561–569.
268445 (J. L.-F.), and CELLEX Foundation (CELLEX-ICIQ high-
8 C. Liu, M. Hu, X. Zhou, J. Wu, L. Zhang, W. Kong, X. Li, X. Zhao,
S. Dai, B. Xu and C. Cheng, NPG Asia Mater., 2018, 10, 552–561.
9 V. Stevanovi ´c , S. Lany, D. S. Ginley, W. Tumas and A. Zunger, Phys.
Chem. Chem. Phys., 2014, 16, 3706–3714.
0 J. H. Rhee, C.-C. Chung and E. W.-G. Diau, NPG Asia Mater., 2013, 5,
e68–e68.
throughput platform) and Dr F. Ungeheuer for his help in the
photocatalytic reactions.
Conflicts of interest
31 Perovskite oxides have been used for microwave-induced catalytic
oxidation of organic pollutants see ref. 32–35.
3
3
3
2 Y. Wang, Y. Wang, L. Yu, R. Wang and X. Zhang, Chem. Eng. J., 2020,
90, 124550.
3 Y. Wang, L. Yu, R. Wang, Y. Wang and X. Zhang, J. Colloid Interface
Sci., 2020, 564, 392–405.
4 Y. Wang, Y. Wang, L. Yu, J. Wang, B. Du and X. Zhang, Chem. Eng. J.,
2019, 368, 115–128.
There are no conflicts to declare.
3
Notes and references
1
2
3
A. Kojima, K. Teshima, Y. Shirai and T. Miyasaka, J. Am. Chem. Soc.,
009, 131, 6050–6051.
A. K. Jena, A. Kulkarni and T. Miyasaka, Chem. Rev., 2019, 119,
036–3103.
H.-S. Kim, C.-R. Lee, J.-H. Im, K.-B. Lee, T. Moehl, A. Marchioro,
2
35 Y. Wang, J. Wang, B. Du, Y. Wang, Y. Xiong, Y. Yang and X. Zhang,
Appl. Surf. Sci., 2018, 439, 475–487.
36 M. Neumann, S. F u¨ ldner, B. K ¨o nig and K. Zeitler, Angew. Chem., Int.
Ed., 2011, 50, 951–954.
3
S.-J. Moon, R. Humphry-Baker, J.-H. Yum and J. E. Moser, Sci. Rep., 37 M. Neumann, S. F u¨ ldner, B. K ¨o nig and K. Zeitler, Angew. Chem.,
012, 2, 591. 2011, 123, 981–985.
M. M. Lee, J. Teuscher, T. Miyasaka, T. N. Murakami and H. J. 38 D. A. Koch, B. J. Henne and D. E. Bartak, J. Electrochem. Soc., 1987,
Snaith, Science, 2012, 338, 643–647. 134, 3062–3067.
Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell- 39 H.-W. Shih, M. N. Vander Wal, R. L. Grange and D. W. C. MacMillan,
efficiency.html, 2019. J. Am. Chem. Soc., 2010, 132, 13600–13603.
X. Zhu, Y. Lin, J. San Martin, Y. Sun, D. Zhu and Y. Yan, Nat. 40 I. Rosa-Pardo, S. Pocov ´ı -Mart ´ı nez, R. Arenal, R. E. Galian and
Commun., 2019, 10, 2843.
J. P ´e rez-Prieto, Nanoscale, 2019, 11, 18065–18070.
X. Zhu, Y. Lin, Y. Sun, M. C. Beard and Y. Yan, J. Am. Chem. Soc., 41 V. K. Ravi, A. Swarnkar, R. Chakraborty and A. Nag, Nanotechnology,
019, 141, 733–738. 2016, 27, 325708.
J. A. Caputo, L. C. Frenette, N. Zhao, K. L. Sowers, T. D. Krauss and 42 A. Call, C. Casadevall, F. Acu n˜ a-Par ´e s, A. Casitas and J. Lloret-Fillol,
D. J. Weix, J. Am. Chem. Soc., 2017, 139, 4250–4253. Chem. Sci., 2017, 8, 4739–4749.
C. Huang, X.-B. Li, C.-H. Tung and L.-Z. Wu, Chem. – Eur. J., 2018, 43 L. Shi, C. He, D. Zhu, Q. He, Y. Li, Y. Chen, Y. Sun, Y. Fu, D. Wen,
4, 11530–11534. H. Cao and J. Cheng, J. Mater. Chem., 2012, 22, 11629–11635.
0 A. K. Simlandy, B. Bhattacharyya, A. Pandey and S. Mukherjee, ACS 44 D. Cardenas-Morcoso, A. F. Gualdr ´o n-Reyes, A. B. Ferreira Vitoreti,
2
4
5
6
7
8
9
2
2
1
Catal., 2018, 8, 5206–5211.
1 V. K. Ravi, G. B. Markad and A. Nag, ACS Energy Lett., 2016, 1, 665–671.
M. Garc ´ı a-Tecedor, S. J. Yoon, M. Solis de la Fuente, I. Mora-Ser ´o
and S. Gimenez, J. Phys. Chem. Lett., 2019, 10, 630–636.
2 S.-Y. Joo, D.-W. Jeong, C.-G. Lee, B.-S. Kim, H.-S. Park and W.-B. Kim, 45 There are evidences of the occurance of halogen-exchange between
1
1
J. Appl. Phys., 2017, 121, 223102.
3 H. Yu, H. Wang, J. Zhang, J. Lu, Z. Yuan, W. Xu, L. Hultman,
CsPbBr
3
and alkane chlorides; this is consistent with interaction
1
between the halides and the NC surface.
A. A. Bakulin, R. H. Friend, J. Wang, X.-K. Liu and F. Gao, Small, 46 D. Parobek, Y. Dong, T. Qiao, D. Rossi and D. H. Son, J. Am. Chem.
019, 15, 1804947. Soc., 2017, 139, 4358–4361.
4 L. Peng, A. Tang, C. Yang and F. Teng, J. Alloys Compd., 2016, 687, 47 W.-B. Wu, Y.-C. Wong, Z.-K. Tan and J. Wu, Catal. Sci. Technol., 2018,
06–513. 8, 4257–4263.
2
1
5
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