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

Abstract

Due to γ-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 photocatalysts.