|Title:||Selective CO2-to-CO photoreduction over an orthophosphate semiconductor via the direct Z-scheme heterojunction of Ag3PO4 quantum dots decorated on SnS2 nanosheets||Authors:||Fu, Fang-Yu
Wu, Chih-, I
|Keywords:||PHOTOCATALYTIC CO2 REDUCTION;CARBON-DIOXIDE;EFFICIENT;DRIVEN;TIO2;NANOPARTICLES;SURFACE;EVOLUTION;DESIGN;FUELS||Issue Date:||Sep-2022||Publisher:||ROYAL SOC CHEMISTRY||Source:||SUSTAIN ENERG FUELS||Abstract:||
Direct Z-scheme heterojunctions are widely used for photocatalytic water splitting and CO2 reduction due to facilitating well-separated photogenerated charge carriers and spatial isolation of redox reactions. Here, using a facile two-step hydrothermal and ion-exchange method, we uniformly decorate silver orthophosphate (i.e., Ag3PO4) quantum dots with an average characteristic size of similar to 10 nm over tin(iv) sulphide (i.e., SnS2) nanosheets to form a 0D/2D heterojunction. The direct Z-scheme mechanism, i.e. charge transport for efficient electron (from SnS2) and hole (from Ag3PO4) recombination, is confirmed by the following experiments: (i) ultraviolet and X-ray photoelectron spectroscopies; (ii) photodeposition of Pt and PbO2 nanoparticles on reduction and oxidation sites, respectively; (iii) in situ X-ray photoelectron spectroscopy; and (iv) electron paramagnetic resonance spectroscopy. Owing to the photoreduction properties of Ag3PO4 with orthophosphate vacancies, Z-scheme charge carrier transfer, and efficient exciton dissociation, an optimized heterojunction shows a high CO2-to-CO reduction yield of 18.3 mu mol g(-1) h(-1) with an illustrious selectivity of similar to 95% under light illumination, which is about 3.0 and 47.8 times larger than that of Ag3PO4 and SnS2, respectively. The carbon source for the CO product is verified using a (CO2)-C-13 isotopic experiment. Moreover, by tracing the peak at similar to 1190 cm(-1) in the dark and under light irradiation, in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrates that the CO2 reduction pathway goes through the COOH* intermediate.
|Appears in Collections:||水產養殖學系|
07 AFFORDABLE & CLEAN ENERGY
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