open access

https://hdl.handle.net/2115/76220

Photocatalytic hydrogen evolution driven by platinated CdS nanorods with a hexacyanidoruthenate redox mediator

英語

2018-12-01

Royal Society of Chemistry

Sustainable energy & fuels

2(12)

2609-2615

We have investigated the effect of hexacyanidometallate [M(CN)(6)](4-) (M = Fe or Ru) redox mediators on the photocatalytic H-2 evolution reaction driven by Pt-cocatalyst-loaded cadmium sulfide nanorods (Pt/CdS-NR). A larger amount of H-2 evolved under blue LED light irradiation ( = 470 +/- 10 nm) in the presence of [Ru(CN)(6)](4-) than in the presence of [Fe(CN)(6)](4-), despite the more positive M(iii)/M(ii) redox potential of [Ru(CN)(6)](4-) (0.89 V vs. NHE) than [Fe(CN)(6)](4-) (0.36 V vs. NHE). PXRD and IR spectral experiments during the photocatalytic H-2 evolution reaction clearly indicate that the Prussian white analogue K-2[CdRu(CN)(6)] (CdRu-PW) was increasingly formed, producing a white precipitate, whereas only a trace amount of K-2[CdFe(CN)(6)] (CdFe-PW) was formed in the reaction with [Fe(CN)(6)](4-). The amount of CdRu-PW produced during the photocatalytic H-2 evolution reaction revealed that the electron source of H-2 evolution is gradually changed from the S2- anions generated following the photocorrosion of CdS to [Ru(CN)(6)](4-) because of effective hole transfer through the Ru(iii)/Ru(ii) redox step in the CdRu-PW (1.42 V vs. NHE) deposited on the CdS-NR surface. The colourless feature and more positive Ru(iii)/Ru(ii) redox potential of CdRu-PW than that of water oxidation suggest that CdRu-PW is a promising hole mediator for solar water splitting.

学術雑誌論文

Accepted Manuscript

2398-4902