Semiconductor photocatalysis. 13. Effective photoreduction of carbon dioxide catalyzed by zinc sulfide quantum crystallites with low density of surface defects
作者:Masashi Kanemoto、Tsutomu Shiragami、Chyongjin Pac、Shozo Yanagida
DOI:10.1021/j100187a062
日期:1992.4
Freshly prepared colloidal ZnS suspensions (ZnS-0) effectively catalyze photoreduction of CO2 in water at pH 7 with NaH2PO2 in the coexistence of Na2S under UV irradiation. With competitive H-2 evolution, formate and a very small quantity of CO were formed with the apparent quantum yield PHI(1/2HCOO-, 0.24 at 313 nm, where H2PO2- was quantitatively photoxidized to HPO32-. The efficiency strongly depends on the pH of the system, preparation methods of ZnS photocatalysts, and synergistic effects of electron donors. Quantized ZnS crystallites with low density of surface defects are indispensable for the effective CO2 reduction. The synergistic effect in the use of both SH- and H2PO2- ions is discussed in terms of spectral properties of the photocatalyst.