Construction of Ultrafine Ag₂S NPs Anchored onto 3D Network Rodlike Bi₂SiO₅ and Insight into the Photocatalytic...

A novel three-dimensional (3D) network rodlike Ag₂S/Bi₂SiO₅ photocatalyst with a p-n heterostructure composed of ultrafine Ag₂S nanoparticles (NPs) and Bi₂SiO₅ nanosheets was prepared using an anionic self-regulation strategy by a two-step hydrothermal process. The architecture facilitated the efficient transfer and separation of photogenerated electron-hole pairs. The optimal Ag₂S/Bi₂SiO₅ composite (ABSO_0.10) exhibited an excellent reduction activity (93.5% Cr(VI) removal in wastewater containing 50 mg·L^-1 Cr(VI) within 90 min under visible light), which was about 11.2 and 25.6 times higher than that of the pristine Ag₂S and virgin Bi₂SiO₅, respectively. Assisted by experiments and density functional theory (DFT) calculations, a possible photocatalytic mechanism for Cr(VI) reduction over the Ag₂S/Bi₂SiO₅ composite under visible-light irradiation was proposed.