Visible-Light Photocatalytic Hydrogen Production Activity of ZnIn2S4 Microspheres Using Carbon Quantum Dots and Platinum as Dual Cocatalysts

ZnIn2S4 microspheres (ZIS MSs) were for the first time decorated with carbon quantum dots (CQDs) and platinum nanoparticles (NPs) as dual co-catalysts of for photocatalytic H-2 production. The ZIS MSs co-loaded with CQDs and Pt exhibited a high photocatalytic H-2 production rate of 1032.2 mu mol h(-1) g(-1) with an apparent quantum efficiency of 2.2% (420 nm) in triethanolamine aqueous solution under visible-light irradiation, which was much higher than the respective photocatalytic rates of pure ZIS, Pt loaded ZIS, and CQDs-decorated ZIS. Such a great enhancement was attributed to the integrative effect of good crystallization, enhanced light absorption, high electrical conductivity of CQDs, and the vectorial electron transfer from ZIS to CQDs and Pt NPs (ZIS-->CQDs-->Pt).