| 1. |
- Wang, Lichao, et al.
(författare)
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Hydrogen-treated mesoporous WO3 as a reducing agent of CO2 to fuels (CH4 and CH3OH) with enhanced photothermal catalytic performance
- 2016
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 4:14, s. 5314-5322
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Tidskriftsartikel (refereegranskat)abstract
- A series of mesoporous WO3 catalysts were facilely synthesized by a hydrothermal method using mesoporous silica KIT-6 as a hard template and silicotungstic acid as a precursor. All the catalysts possess a well-defined mesoporous structure with interconnected networks. Oxygen-deficient mesoporous WO3 (m-WO3-x) was prepared by hydrogenation treatment at different temperatures with improved photothermal coupling performance. Moreover, the as-prepared catalysts exhibit selectivity toward CH4 evolution under visible-light only irradiation. Then, under photothermal conditions, the results show that the concentration of oxygen vacancies of m-WO3 has a great influence on its catalytic performance. The CH4 evolution rate reached 25.77 mu mol g (1), which is about 22 times that of mesoporous WO3 (1.17 mu mol g(-1)) under the same conditions, and a moderate concentration of oxygen vacancies is necessary to achieve selectivity for the conversion of CO2 into CH4. A mechanism of the catalytic reduction of CO2 over m-WO3-x is proposed, in which the initial oxygen vacancies function as an excellent electron transfer mediator and decompose CO2 into its elements (C/CO). These findings may further broaden the scope for photothermal chemical conversion and provide new insights into the oxygen nonstoichiometry strategy for the development of CO2 reduction.
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| 2. |
- Ha, Minh Ngoc, et al.
(författare)
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Morphology-controlled synthesis of SrTiO3/TiO2 heterostructures and their photocatalytic performance for water splitting
- 2016
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 6:25, s. 21111-21118
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Tidskriftsartikel (refereegranskat)abstract
- Different morphologies of SrTiO3/TiO2 heterostructures like nanocubes, nanoparticles, nanospheres, and nanofibers were synthesized via a facile hydrothermal process using TiO2 as both a template and precursor in Sr(OH)(2) solution. Their structure, interface and composition can be rationally tailored by simply adjusting the Sr(OH)(2)/TiO2 (Sr/Ti) mole ratios and the morphology of SrTiO3/TiO2 heterostructures can be controlled easily using TiO2 with different morphologies. A SrTiO3 crystal thin layer was grown on an anatase TiO2 substrate to fabricate a heterostructure interface contact between SrTiO3 and TiO2 and the lattice mismatch had an effect on the electrical transport properties. The SrTiO3/TiO2 heterostructures are beneficial for the fast separation of photogenerated electrons and holes so as to suppress the recombination of photogenerated electrons and holes at the interface of SrTiO3 and TiO2. Besides this, the different morphologies of the SrTiO3/TiO2 heterostructures allowing facile electron transfer, the hierarchical structure promoting mass transfer and allowing more light reflection and absorption, and the large specific surface area providing more reaction sites to facilitate the reactants to the desired oxidation places all together create a synergistic effect to improve the photocatalytic activity of the hierarchical SrTiO3/TiO2 heterostructures. Under the irradiation of UV light, in a water/methanol sacrificial reagent system, the SrTiO3/TiO2 NP heterostructures at a Sr/Ti mole ratio of 40% with the highest BET and smallest crystallite size achieve the highest photocatalytic activity generating 0.731 mmol of H-2. The SrTiO3/TiO2 heterostructures exhibit better photocatalytic activity by generating three times more H-2 than bare TiO2 and pure SrTiO3.
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| 3. |
- Wang, Lichao, et al.
(författare)
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Mesoporous WO3 modified by Mo for enhancing reduction of CO2 to solar fuels under visible light and thermal conditions
- 2016
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Ingår i: Integrated Ferroelectrics. - : Taylor & Francis. - 1058-4587 .- 1607-8489. ; 172:1, s. 97-108
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Tidskriftsartikel (refereegranskat)abstract
- Mesoporous WO3 (m-WO3) was synthesized by a hydrothermal method using mesoporous silica KIT-6 as a hard template and silicotungstic acid as a precursor. The m-WO3 modified by molybdenum (Mo) nanoparticles could be used as a stable catalyst for photo-thermal inducing CO2 reducting reactions for solar fuels. Under visible light irradiation (lambda > 420 nm) and 250-, the catalytic activity of m-Mo/WO3 for the CH4 and CH3 OHevolution was found to be higher than that of m-WO3 and commercial WO3. The amount of evolved CH3OH from m-Mo/WO3 has reached 13.80 mu molg(-1) in 1 2 h, which is ca. 10 times as high as that of c-WO3 (1.36 mu molg(-1)) and 6.5 times as high as that of m-WO3 (2.12 mu molg(-1)), making it attractive for practical applications.
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