Layered Metal Chalcogenide ZnIn₂S₄ Anchored with Nickel Metal Dots for Efficient Photocatalytic Production of Hydrogen Peroxide and Degradation of Sulfamethoxazole

Photocatalytic oxygen reduction reaction (ORR) through a two-electron pathway is a green, sustainable route for hydrogen peroxide (H2O2) production. An outstanding visible-light-driven photocatalyst ZnIn2S4 (ZIS) with anchoring nickel metal dots (Ni0) less than one nanometer, namely, Ni/ZIS, has been successfully synthesized for H2O2 production followed by effective degradation of sulfamethoxazole (SMX). As compared with the pristine, the Ni/ZIS H2O2 production capacity exhibit 5 times the H2O2 yield of >40.9 mu mol/L in the presence of visible light illumination (lambda = 420-630 nm). The light absorption capacity, photogenerated electron transfer rate, and lower recombination rate of photoelectron/hole pairs were improved through Ni metal dots, which was demonstrated in this study. Under the condition of visible light irradiation for 1 h, 1.5 mg/L SMX by 10 mg 1.0 wt % % Ni/ZIS was degraded over 93%. This study presents a facile strategy for enhancing photocatalysis of metal chalcogenide on H2O2 production in the visible-light wavelength. It has potential for water purification by consuming on-site H2O2 production under solar illumination.