Photocatalytic hydrogen production under visible-light irradiation on (CuAg)_0.15In_0.3Zn_1.4S₂ synthesized by precipitation and calcination

This study investigates the photocatalytic hydrogen production over nanosized (CuAg)_0.15In_0.3Zn_1.4S₂ photocatalysts prepared via precipitation and calcination. The photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N₂ adsorption-desorption, and UV-Vis absorption spectroscopy. The results show that calcination temperature and time significantly influence the crystallinity, specific surface area, and visible-light absorption capacity of the photocatalysts. The photocatalyst activity was studied under visible-light irradiation with KI as the electron donor. The results indicate that the (CuAg)_0.15In_0.3Zn_1.4S₂ photocatalyst prepared at a calcination temperature of 600°C for 5 h yields the highest photocatalytic activity (H₂ production rate of 1750 μmol g^-1 h^-1 and quantum yield of 12.8% at 420 ± 5 nm), approximately 6 times larger than that of catalysts prepared without thermal treatment.