20338-08-3Relevant articles and documents
Charge carrier dynamics and photocatalytic behavior of TiO2 nanopowders submitted to hydrothermal or conventional heat treatment
Patrocinio,Schneider,Fran?a,Santos,Caixeta,Machado,Bahnemann
, p. 70536 - 70545 (2015)
The sol-gel technique followed by conventional (TiO2-1) and hydrothermal (TiO2-2) thermal treatment was employed to prepare TiO2-based photocatalysts with distinct particle sizes and crystalline structures. The as prepared metal oxides were evaluated as photocatalysts for gaseous HCHO degradation, methanol, and dye oxidation reactions. Additionally, metallic platinum was deposited on the TiO2 surfaces and H2 evolution measurements were performed. The photocatalytic activities were rationalized in terms of morphologic parameters along with the electron/hole dynamics obtained from transient absorption spectroscopy (TAS). TiO2-2 exhibits smaller particle size, poorer crystallinity, and higher surface area than TiO2-1. Moreover the hydrothermal treatment leads to formation of the metastable brookite phase, while TiO2-1 exhibits only the anatase phase. TAS measurements show that the electron/hole recombination of TiO2-2 is faster than that of the latter. Despite that, TiO2-2 exhibits higher photonic efficiencies for photocatalytic oxidation reactions, which is attributed to its larger surface area that compensates for the decrease of the surface charge carrier concentration. For H2 evolution, it was found that the surface area has only a minor effect and the photocatalyst performance is controlled by the efficiency of the electron transfer to the platinum islands. This process is facilitated by the higher crystallinity of TiO2-1, which exhibits higher photonic efficiency for H2 evolution than that observed for TiO2-2. The results found here provide new insights into the correlations between thermal treatment conditions and photocatalytic activity and will be useful for the design of high performance photocatalysts.
Polyol mediated synthesis of tungsten trioxide and Ti doped tungsten trioxide. Part 1: Synthesis and characterisation of the precursor material
Porkodi,Yegnaraman,Jeyakumar
, p. 1476 - 1486 (2006)
Polyol mediated synthesis for the preparation of tungsten trioxide and titanium doped tungsten trioxide has been reported. The reaction was carried out using chlorides of tungsten and titanium in diethylene glycol medium and water as the reagent for hydrolysis at 190 °C. Formation of a blue coloured dimensionally stable suspension of the precursor materials was observed during the course of the reaction. The particle sizes of the precursor materials were observed to be around 100 nm. The precursor materials were annealed to give tungsten trioxide and titanium doped tungsten trioxide. The precursor materials were characterised using TGA/DTA, FT-IR, optical spectra, SEM, TEM and powder XRD methods. It was observed that the doping of titanium could be effected at least up to 10% of Ti in WO3. The TGA/DTA studies indicated that WO3-x·H2O is the dominant material that formed during the polyol mediated synthesis. The XRD data of the annealed samples revealed that the crystalline phase could be manipulated by varying the extent of titanium doping in the tungsten trioxide matrix.
Removal of ciprofloxacin from aqueous solution using long TiO2 nanotubes with a high specific surface area
Zheng, Kai,Zheng, Xingye,Yu, Fei,Ma, Jie
, p. 3625 - 3631 (2016)
Long TiO2 nanotubes (TNs) were successfully prepared by the reaction of TiO2 and NaOH. The raw materials were treated by stirring, ion exchange, centrifugation, and freeze-drying, and then the target TNs was synthesized. Anatase TNs were obtained by calcinating the TNs at 823 K for 4.5 h. The TNs were characterized by Brunauer-Emmett-Teller surface area analysis, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectrometry. The results indicated that the TNs had a larger specific surface area (ca. 160 m2 g-1) and pore volume (ca. 0.6 cm3 g-1) than the commercial product P25. The adsorption of ciprofloxacin onto the TNs was compared with their adsorption onto P25. The adsorption isotherm, kinetics, and regeneration performance were investigated. The experimental results indicated that the maximum adsorption capacity of the TNs and P25 was 26.38 and 5.32 mg g-1, respectively, and their adsorption behavior was better fitted by the Langmuir model than by the Freundlich model. The kinetic regression results showed that the adsorption kinetics were more accurately represented by a pseudo-second-order model than by a pseudo-first-order model; the rate of the pseudo-second-order reactions on P25 and the anatase TNs were 0.0442 and 0.27463 min-1, respectively. After adsorption, the TNs had better regeneration properties than P25 under UV irradiation at 500 W for 3 h in 5 mL of aqueous solution. These results show that long TNs have a better adsorption capacity and regeneration properties than P25. This study provides a green method for the removal of organic pollutants by combining enrichment by adsorption with photocatalytic degradation.
Low-temperature synthesis of anatase TiO2 nanoparticles with tunable surface charges for enhancing photocatalytic activity
Li, Ye,Qin, Zhenping,Guo, Hongxia,Yang, Hanxiao,Zhang, Guojun,Ji, Shulan,Zeng, Tingying
, (2014)
In this work, the positively or negatively charged anatase TiO2 nanoparticles were synthesized via a low temperature precipitation-peptization process (LTPPP) in the presence of poly(ethyleneimine) (PEI) and poly(sodium4- styrenesulfonate) (PSS). X-ray diffraction (XRD) pattern and high-resolution transmission electron microscope (HRTEM) confirmed the anatase crystalline phase. The charges of the prepared TiO2, PEI-TiO2 and PSS-TiO2 nanoparticles were investigated by zeta potentials. The results showed that the zeta potentials of PEI-TiO2 nanoparticles can be tuned from +39.47 mV to +95.46 mV, and that of PSS-TiO2 nanoparticles can be adjusted from -56.63 mV to -119.32 mV. In comparison with TiO2, PSS-TiO2 exhibited dramatic adsorption and degradation of dye molecules, while the PEI modified TiO2 nanoparticles showed lower photocatalytic activity. The photocatalytic performances of these charged nanoparticles were elucidated by the results of UV-vis diffuse reflectance spectra (DRS) and the photoluminescence (PL) spectra, which indicated that the PSS-TiO2 nanoparticles showed a lower recombination rate of electron-hole pairs than TiO2 and PEI-TiO2.
Fabrication and characterization of nano TiO2 thin films at low temperature
Ge, Lei,Xu, Mingxia,Sun, Ming,Fang, Haibo
, p. 1596 - 1603 (2006)
Anatase TiO2 thin films were successfully prepared on glass slide substrates via a sol-gel method from refluxed sol (RS) containing anatase TiO2 crystals at low temperature of 100 °C. The influences of various refluxing time on crystallinity, morphology and size of the RS sol and dried TiO2 films particles were discussed. These samples were characterized by infrared absorption spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission-scanning electron microscopy (FE-SEM) and UV-vis absorption spectroscopy (UV-vis). The photocatalytic activities of the TiO2 thin films were assessed by the degradation of methyl orange in aqueous solution. The results indicated that titania films thus obtained were transparent and their maximal light transmittance exceeded 80% under visible light region. The TiO2 thin films prepared from RS-6 sol showed the highest photocatalytic activity, when the calcination temperature is higher than 300 °C. The degradation of methyl orange of RS-6 thin films reached 99% after irradiated for 120 min, the results suggested that the TiO2 thin films prepared from RS sol exhibited high photoactivities.
Systematic study of TiO2/ZnO mixed metal oxides for CO2 photoreduction
Thompson, Warren A.,Olivo, Alberto,Zanardo, Danny,Cruciani, Giuseppe,Menegazzo, Federica,Signoretto, Michela,Maroto-Valer, M. Mercedes
, p. 21660 - 21666 (2019)
A two component three degree simplex lattice experimental design was employed to evaluate the impact of different mixing fractions of TiO2 and ZnO on an ordered mesoporous SBA-15 support for CO2 photoreduction. It was anticipated that the combined advantages of TiO2 and ZnO: low cost, non-toxicity and combined electronic properties would facilitate CO2 photoreduction. The fraction of ZnO had a statistically dominant impact on maximum CO2 adsorption (β2 = 22.65, p-value = 1.39 × 10-4). The fraction of TiO2 used had a statistically significant positive impact on CO (β1 = 9.71, p-value = 2.93 × 10-4) and CH4 (β1 = 1.43, p-value = 1.35 × 10-3) cumulative production. A negative impact, from the interaction term between the fractions of TiO2 and ZnO, was found for CH4 cumulative production (β3 = -2.64, p-value = 2.30 × 10-2). The systematic study provided evidence for the possible loss in CO2 photoreduction activity from sulphate groups introduced during the synthesis of ZnO. The decrease in activity is attributed to the presence of sulphate species in the ZnO prepared, which may possibly act as charge carrier and/or radical intermediate scavengers.
Layer-by-layer self-assembled hollow titania composite nanospheres containing [60]fullerene
Jiang, Wenfeng,Yu, Ying,Li, Dianqing,Zhao, Yingjie,Xu, Maoyou,Shi, Zhiqiang
, p. 581 - 583 (2008)
Core-shell nanospheres, titania composite nanospheres containing [60]fullerene, were fabricated with sizes of about 100 nm by a layer-by-layer self-assembly procedure, and were characterized by TGA, FT-IR and XPS spectroscopy. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Control of phase and pore structure of titania powders using HCl and NH4OH catalysts
Song, Ki Chang,Pratsinis, Sotiris E.
, p. 92 - 98 (2001)
Porous titania powders were prepared by hydrolysis of titanium tetraisopropoxide (TTIP) and were characterized at various calcination temperatures by nitrogen adsorption, X-ray diffraction, and microscopy. The effect of HCl or NH4OH catalysts a
Sulfate-promoted titania photocatalyst for high efficiency gas phase toluene degradation
Barraud, Elodie,Bosc, Florence,Keller, Nicolas,Keller, Valerie
, p. 336 - 337 (2005)
A regenerable, halide-free, sulfate-promoted titania photocatalyst was developed for the high-efficiency, room temperature gas phase photodegradation of toluene at higher than trace concentrations. Copyright
Supported Au Catalysts Prepared from Au Phosphine Complexes and As-Precipitated Metal Hydroxides: Characterization and Low-Temperature CO Oxidation
Yuan, Youzhu,Kozlova, Anguelina P.,Asakura, Kiyotaka,Wan, Huilin,Tsai, Khirui,Iwasawa, Yasuhiro
, p. 191 - 199 (1997)
Supported Au catalysts were prepared by attaching Au phosphine complexes, Au(PPh3)(NO3) (1) and [Au9(PPh3)8](NO3)3 (2), on as-precipitated metal hydroxides M(OH)*x (*, as-precipitated; M = Mn2+, Co2+, Fe3+, Ni2+, Zn2+, Mg2+, Cu2+, Ti4+, Ce4+, and La3+), followed by temperature-programmed calcination in a flow of dry air. The obtained Au catalysts showed high catalytic activities in low-temperature CO oxidation. Among the obtained Au catalysts 1/Mn(OH)*2 and 1/Co(OH)*2 were most highly active even at 203 K. 1/Fe(OH)*3 and 1/Ti(OH)*4 also catalyzed CO oxidation at low temperatures 203-273 K, whereas 1/Fe2O3 and 1/TiO2 prepared by supporting 1 on conventional Fe2O3 and TiO2 showed negligible activity under the similar reaction conditions. It was estimated by TEM and XRD that the mean diameter of Au particles in 1/Fe(OH)*3 was about 2.9 nm, which was about 10 times smaller than that for 1/Fe2O3. EXAFS for 1/Ti(OH)*4 revealed that the coordination number of Au-Au bond was 8-10, while that for 1/TiO2 was 11.0, which also indicates that Au particle size for 1/Ti(OH)*4 is smaller than that for 1/TiO2. The catalysts obtained by attaching the Au complexes on commercially available metal hydroxides also showed negligible activity for the low-temperature CO oxidation under identical conditions. These results demonstrate that supported Au catalysts with small Au particles, tremendously active for the low-temperature CO oxidation, can be prepared by attaching the Au phosphine complexes on the as-precipitated metal hydroxides. Sodium cations exhibited positive effect on the Au catalysis, whereas chloride anions drastically decreased the CO oxidation activity.
TAP study on carbon monoxide oxidation over supported gold catalysts Au/Ti(OH)*4 and Au/Fe(OH)*3: Moisture effect
Olea, Maria,Tada, Mizuki,Iwasawa, Yasuhiro
, p. 60 - 67 (2007)
The effect of moisture on the behavior of the active supported gold catalysts developed by us, Au/Ti(OH)*4 (I) and Au/Fe(OH)*3 (II), during CO activation and CO oxidation in the temperature range 298-473 K was investigated by the temporal analysis of products (TAP) technique. The oxidation reaction over the Au/Ti(OH)*4 catalyst was totally suppressed by the presence of water, independent of the water content of 200 and 1000 ppm, the carbon monoxide-to-oxygen ratio, and the temperature. In contrast, the presence of water vapors showed no effect on CO oxidation over the Au/Fe(OH)*3 catalyst. For both catalysts, the carbon monoxide adsorption feature was unalterable by the presence of water, namely CO molecules reversibly adsorbed on the catalyst surface, but the amount of CO adsorbed decreased by increasing water content. When a reaction mixture at a 1:1 ratio of CO to O2 was pulsed on the catalyst in the absence of water, the CO response curve showed two peaks, whereas in the presence of water, the TAP response curve showed only one peak. At a 1:3 CO-to-O2 ratio, the CO response curve showed only one peak, which shifted to a shorter time and narrowed in the absence of water. The shift was more pronounced on catalyst (II). The TAP experiments provided indirect evidence that CO and water adsorbed together (CO weakly and water strongly) and water blocked [irreversibly for Au/Ti(OH)*4 and reversibly for Au/Fe(OH)*3], the adsorption sites for oxygen.
Nanosized anatase TiO2 as precursor for preparation of sulfated titania catalysts
Ma, Zhen,Yue, Yinghong,Deng, Xingyi,Gao, Zi
, p. 97 - 104 (2002)
Nanosized anatase TiO2 has been prepared by a sol-gel hydrothermal process. The effect of water:alkoxide molar ratio, hydrothermal aging temperature and aging time on the properties of the nanocrystalline anatase TiO2 was investigated in detail. The specific surface area, sulfur content and surface acidity of sulfated titania catalysts prepared by sulfation of sol-gel hydrothermal derived nanocrystalline TiO2 were greater than those of the analogous catalyst prepared from ordinary amorphous titania hydrate. The former catalysts displayed higher catalytic activities in isopropanol dehydration, cumene cracking and n-pentane conversion reactions. The influence of the crystalline state and crystalline grain of titania precursors on the properties of sulfated titania catalysts was studied and discussed.
Chemical synthesis, structural, thermo-physical and electrical property characterization of PLZT ceramics
James,Kumar, Rajesh,M., PremKumar,Srinivas,Radha,Vithal,Vijayakumar
, p. 624 - 627 (2010)
The sol-gel process was employed to prepare (Pb1-xLax)(Zr1-yTiy)O3 (PLZT) ceramics with nominal composition (Pb0.92La0.08)(Zr0.60Ti0.40)O3. X-ray diffraction results showed that the perovskite PLZT phase is formed at room temperature itself. The average size distribution of the particles was obtained by small angle X-ray scattering (SAXS). Nano-crystalline particles with a size of the order of ～30 nm were found. Morphological studies were carried out by SEM analyses to observe the grain structure. TG-DTA and DSC studies were used to analyze the thermal properties of the nano-powders, in order to understand the reaction kinetics in them. Poled bulk ceramic samples prepared from the sol-gel derived powders were subjected to electrical measurements, in order to determine the piezoelectric and electromechanical coupling coefficients.
Hierarchically porous TiO2/SiO2 fibers with enhanced photocatalytic activity
Hou, Huilin,Wang, Lin,Gao, Fengmei,Wei, Guodong,Zheng, Jinju,Tang, Bin,Yang, Weiyou
, p. 19939 - 19944 (2014)
While TiO2 nanoparticles are one of the most promising photocatalysts, their applications have been greatly hindered by easy aggregation. One of the effective routes to solve this problem is to incorporate them on/in a solid carrier. In this paper, we report the fabrication of hierarchically porous TiO2/SiO2 fibers via an electrospinning technique combined with subsequent high-temperature calcination treatment, in which the hierarchically porous SiO2 fibers confer a platform to assemble TiO2 nanoparticles with a uniform spatial distribution. The resultant hierarchically porous TiO2/SiO 2 fibers have shown an enhanced photocatalytic activity with ～95% degradation of rhodamine B as compared to ～75% using our synthesized TiO2 nanoparticles and ～77% using commercially available Degussa P25 after 120 min illumination.
Tanaka, Tsunehiro,Kumagai, Hideaki,Hattori, Hideshi,Kudo, Masahiko,Hasegawa, Sadao
, p. 221 - 226 (1991)
Gas phase photocatalytic removal of toluene effluents on sulfated titania
Barraud, Elodie,Bosc, Florence,Edwards, David,Keller, Nicolas,Keller, Valerie
, p. 318 - 326 (2005)
Photocatalytic removal of toluene in the gas phase was carried out over UV-illuminated sulfated titania materials in a cylinder-like continuous reactor. A series of SO42 - TiO2 samples was obtained from the addition of H2SO4 on an amorphous titanium hydroxide gel synthesized according to a classical sol-gel procedure. The wide variety of materials led to varying photocatalytic behaviors depending strongly on the experimental synthesis parameters, having a determinant influence on the surface specific area, the crystallinity of the material, the crystallographic nature of TiO 2, and the sulfate surface content. Optimization of the experimental parameters, such as the molarity of the sulfation solution, varying in the range 0.25-5 M leading to surface sulfate coverage of 2.5-14 wt%, and the calcination temperature ranging from 400 to 800 °C, promoted enhanced photocatalytic performance toward toluene removal as compared with commercially available P25 TiO2 and sulfate-free sol-gel TiO2. The most efficient photocatalyst was obtained for a near-monolayer sulfate coverage corresponding to the presence of both TiO2 and well-dispersed SO42- with optimized contact between SO42- and TiO2 domains. Furthermore, a positive role of sulfates is attributed both to an electron transfer from titanium to sulfates, leading to a positive charge trap effect, and to better desorption of electron-rich sp2-bound carbon aromatic poisons, thus limiting deactivation.
Site Sensitivity of Interfacial Charge Transfer and Photocatalytic Efficiency in Photocatalysis: Methanol Oxidation on Anatase TiO2 Nanocrystals
Fu, Cong,Li, Fei,Zhang, Jiachen,Li, Dan,Qian, Kun,Liu, Yong,Tang, Junwang,Fan, Fengtao,Zhang, Qun,Gong, Xue-Qing,Huang, Weixin
, p. 6160 - 6169 (2021)
Photocatalytic oxidation of methanol on various anatase TiO2 nanocrystals was studied by in situ and time-resolved characterizations and DFT calculations. Surface site and resulting surface adsorbates affect the surface band bending/bulk-to-surface charge migration processes and interfacial electronic structure/interfacial charge transfer processes. TiO2 nanocrystals predominantly enclosed by the {001} facets expose a high density of reactive fourfold-coordinated Ti sites (Ti4c) at which CH3OH molecules dissociate to form the CH3O adsorbate (CH3O(a)Ti4c). CH3O(a)Ti4c localized density of states are almost at the valence band maximum of TiO2 surface, facilitating the interfacial hole transfer process; CH3O(a)Ti4c with a high coverage promotes upward surface band bending, facilitating bulk-to-surface hole migration. CH3O(a)Ti4c exhibits the highest photocatalytic oxidation rate constant. TiO2 nanocrystals enclosed by the {001} facets are most active in photocatalytic methanol oxidation.
Preparation, Characterization, and Photoactivity of Polycrystalline Nanostructured TiO2 Catalysts
Addamo, Maurizio,Augugliaro, Vincenzo,Di Paola, Agatino,García-López, Elisa,Loddo, Vittorio,Marcí, Giuseppe,Molinari, Raffaele,Palmisano, Leonardo,Schiavello, Mario
, p. 3303 - 3310 (2004)
Various preparations of nanostructured TIO2 starting from Ti(iso-OC3H7)4 or TiCl4 are reported. The samples were characterized by X-ray diffractometry, specific surface area and porosity determinations, scanning and transmission electron microscopy, and diffuse reflectance spectroscopy. 4-Nitrophenol photodegradation in aqueous medium was employed as a probe reaction to test the photoactivity of the catalysts. The photoactivity of some samples derived from Ti(iso-OC 3H7)4 was found comparable with that of commercial powders. Calcination after the hydrolysis process was necessary to achieve crystallization of the particles before using them as photocatalysts for the reaction studied. The samples deriving from TiCl4 were the most photoactive among the home-prepared catalysts, and neither filtration nor calcination was needed to obtain a highly photoactive anatase phase.
Preparation of WO3-modified TiO2 thin film by peroxo sol–gel method and its photocatalytic activity in degradation of methylene blue
Chen, Yu-Wen,Wu, Jia-Ying
, (2020)
A series of WO3-modified TiO2 sols with various WO3 contents were synthesized by peroxo sol–gel method using H2O2 as the agent. The as-synthesized WO3-TiO2 sols were light yellow in color. The maximum amount of WO3 which could be incorporated into the TiO2 sol was 4?wt.percent. The pH values of the as-prepared sols were near neutral. These sols were very stable even after 2?years in stock. The sols were used to coat on glass substrate. The XRD patterns and the SAED patterns indicated that the phase of TiO2 was anatase. There were no characteristic XRD peaks of WO3 in the WO3-modified TiO2 sol, possibly due to low WO3 loading. The particles were rhombus shaped with the major axis and minor axis of 30–77?nm and 15–31?nm, respectively. WO3 was incorporated into the surface structure of TiO2 and modified the electronic state of Ti. The film coated onto glass substrate was very uniform, and the film thickness was ~ 160?nm. The XPS results exhibited that W existed as 5 + and 6 + oxidation states and Ti existed in Ti3+ and Ti4+. These four chemical states play a role of gathering the photogenerated holes and capturing the photogenerated electrons in the lower conduction band of WO3, respectively. This can effectively enhance the separation rate of photogenerated electron–hole pairs and increase the photoactivity. WO3/TiO2 samples had high photocatalytic activity under UV light illumination to degrade methylene blue, because it had high OH and O2? group contents.
Influence of transition metals on the surface acidic properties of titania prepared by sol-gel route
Shali,Sugunan
, p. 1777 - 1783 (2007)
A series of titania catalysts containing chromium, molybdenum as well as tungsten has been prepared by colloidal sol-gel route using metatitanic acid as the precursor. Structural characterization of the prepared catalysts was done with Energy dispersive X-ray analysis, X-ray diffraction, BET surface area and pore volume measurements. The influence of different transition metals like chromium, molybdenum and tungsten on the surface acidic properties of titania is investigated in detail. Two independent methods have been used to study the surface acidity of these catalyst systems: temperature programmed desorption of ammonia which is a measure of total acidity and thermodesorption studies using 2,6-dimethyl pyridine which is a measure of Bronsted acidity. Cumene cracking reaction is carried out over the prepared systems for further characterizing the acidity of the prepared catalysts. Remarkable enhancement in the surface acidity is observed after transition metal incorporation. The catalytic activity of the prepared catalysts was tested towards the dehydrogenation of cyclohexane.
Synthesis and ionic conductivity of lithium-conducting titanium phosphate solid electrolytes
Kunshina,Gromov,Kuz'min,Seitenova,Lokshin,Kalinnikov
, p. 915 - 920 (2004)
Solid electrolytes were synthesized in the systems Li2O-Al 2O3-TiO2-P2O5 and Li 2O-Al2O3-TiO2-P2O 5-H2O-H2O2. Their ionic conductivities were studied and compared. The possibility of obtaining a film of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte on a sapphire substrate from an aqueous peroxide solution of a precursor was analyzed.
A facile hydrothermal method for the controllable synthesis of TiO2 nanocrystals with tunable shapes
Nie, Shengchao,Zhao, Xiujian,Liu, Baoshun
, p. 103386 - 103393 (2015)
The controllable preparation of anatase TiO2 nanocrystals with tunable shapes has drawn much attention recently. The general method used to prepare such nano-TiO2 involves the use of HF as a surfactant. However, the use of HF should be avoided due to its high risk. Therefore, the development of facile and friendly methods to controllably synthesize anatase TiO2 nanocrystals is important. In this research, instead of general titanium precursors, titanium peroxide sol was used as the raw material to synthesize anatase TiO2 nanocrystals due to its high stability in water. Oleic acid and oleylamine were used as capping surfactants. A hydrothermal method, without the use of high risk HF, was developed to prepare uniform anatase TiO2 nanocrystals with various shapes, which can be tuned from octahedral bipyramidal, to truncated octahedral bipyramidal, and then to nano-sheets. The ratio between {001} and {101} surfaces can be easily tuned by changing the amounts of oleic acid and oleylamine used. The photocatalytic activity of these anatase TiO2 nanocrystals was also evaluated through crystal violet photo-degradation under UV light illumination. It was shown that the anatase TiO2 nanocrystals can present a photocatalytic activity comparable to that of commercial P25.
Room temperature synthesized BaTiO3 for photocatalytic hydrogen evolution
Chen, Tao,Meng, Jie,Wu, Shiyan,Pei, Jingyun,Lin, Qingyun,Wei, Xiao,Li, Jixue,Zhang, Ze
, p. 184 - 189 (2018)
As a photocatalyst, barium titanate (BaTiO3) has shown a great potential in photocatalytic water splitting for hydrogen evolution. In this work, BaTiO3 nanoparticles were synthesized at room temperature conditions under ambient pressure. The small particle size below 10 nm plays a key role in suppressing the recombination of photo-induced carriers, and thus promoting the photocatalytic activity. The photocatalytic hydrogen evolution rates of BaTiO3 (BTO-R) synthesized at room temperature are 8 and 2.9 times that of commercial BaTiO3 (BTO-C) in the presence and absence of triethanolamine (TEOA) as a sacrificial agent, respectively. This work provides a good example on size control, low-cost synthesis and photocatalysts' design.
