Unusual aliovalent Cd doped γ-Bi₂MoO₆ nanomaterial for efficient photocatalytic degradation of sulfamethoxazole and rhodamine B under visible light irradiation

Due to gamma-Bi₂MoO₆ (BMO) has attracted considerable attention because of its unique layered perovskite structure and excellent electrical conductivity. However, the easy recombination of electron-hole pairs limits its practical application. To address this issue, we successfully prepared aliovalent Cd²⁺ doped BMO (Cd-BMO) by using a simple hydrothermal method for the degradation of the sulfamethoxazole (SMZ) and Rhodamine B (RhB). The result found that the degradation efficiency of Cd-BMO is significantly higher than that of BMO, despite an increase in the bandgap after the introduction of Cd²⁺. The superior degradation efficiency of 8% Cd-BMO, with a smaller particle size and larger specific surface area, can be attributed to its fast charge separation efficiency, low charge transfer resistance, and low rate of electron-hole pair recombination. Repeated and ion spillover experiments prove that 8% Cd-BMO shows good stability and environmental protection. Theoretical simulation demonstrates that Cd offers electrons to the BMO system due to the decreased binding energy of BMO. The 8% Cd-BMO sample can provide a suitable electric band edge for generating dominant active radicals during degradation. This work not only provides a potential candidate of 8% Cd-BMO for practical degradation but also sheds light on the design of superior photocatalyst. © 2023 The Authors.