In:
Sustainable Energy & Fuels, Royal Society of Chemistry (RSC), Vol. 6, No. 19 ( 2022), p. 4418-4428
Kurzfassung:
Direct Z-scheme heterojunctions are widely used for photocatalytic water splitting and CO 2 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. , Ag 3 PO 4 ) quantum dots with an average characteristic size of ∼10 nm over tin( iv ) sulphide ( i.e. , SnS 2 ) nanosheets to form a 0D/2D heterojunction. The direct Z-scheme mechanism, i.e. charge transport for efficient electron (from SnS 2 ) and hole (from Ag 3 PO 4 ) recombination, is confirmed by the following experiments: (i) ultraviolet and X-ray photoelectron spectroscopies; (ii) photodeposition of Pt and PbO 2 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 Ag 3 PO 4 with orthophosphate vacancies, Z-scheme charge carrier transfer, and efficient exciton dissociation, an optimized heterojunction shows a high CO 2 -to-CO reduction yield of 18.3 μmol g −1 h −1 with an illustrious selectivity of ∼95% under light illumination, which is about 3.0 and 47.8 times larger than that of Ag 3 PO 4 and SnS 2 , respectively. The carbon source for the CO product is verified using a 13 CO 2 isotopic experiment. Moreover, by tracing the peak at ∼1190 cm −1 in the dark and under light irradiation, in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrates that the CO 2 reduction pathway goes through the COOH* intermediate.
Materialart:
Online-Ressource
ISSN:
2398-4902
Sprache:
Englisch
Verlag:
Royal Society of Chemistry (RSC)
Publikationsdatum:
2022
ZDB Id:
2882651-6
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