Cu-doped ZnS hollow particle with high activity for hydrogen generation from alkaline sulfide solution under visible light

Visible light sensitive and highly active Cu-doped ZnS hollow photocatalyst particles Cu-ZnS-shell were successfully developed. These particles could generate H-2 through photocatalytic decomposition of HS- ion in Na2S solution. The photoactivity under xenon lamp irradiation was 6 and 130 times higher than that of copper-free ZnS-shell and coprecipitated ZnS particles, respectively. Cu-ZnS-shell particles were prepared by doping the ZnS-shell particles synthesized using zinc oxide as precursor with Cu, utilizing the difference in ionization tendency between zinc and copper. Though the photoactivity of ZnS-shell was higher than that of coprecipitated ZnS, their photoactivity under visible light conditions was low. However, the Cu-ZnS-shell was active to light of wavelengths higher than 440 nm and is preferred over US, which requires an expensive support metal catalyst such as platinum to decompose HS- ion.