Comparative Study of Metal-Ion-Doped BiOCl for Electroassisted Photocatalytic Degradation of Methyl Orange in Wastewater

In response to escalating water pollution, electroassisted photocatalysis integrates an external electric field with photocatalysis to enhance wastewater treatment efficiency. Bismuth oxychloride (BiOCl) is considered a highly promising photoanode material due to its outstanding photocatalytic activity. However, its wide bandgap and limited visible light response restrict its practical applications. Herein, the effects of Mg 2+, Nd 3+, Mn 2+ and Ce 3+ doping on the band structure and electroassisted photocatalytic performance of BiOCl are systematically compared. Among the investigated dopants, Nd 3+ most effectively narrows the bandgap and extends the photoresponse range. Nd-BiOCl with a feed ratio of 60% exhibits optimal charge separation and transport, achieving a methyl orange degradation efficiency of 97.34% within 45 min under simulated sunlight. Based on a systematic and comparative analysis of multimetal-ion doping, this study elucidates the intrinsic advantages of Nd 3+ in tailoring the band structure of BiOCl, facilitating photogenerated charge carrier migration, and ultimately enhancing electroassisted photocatalytic efficiency. These insights establish a systematic material design paradigm and provide a strategic basis for the development of highly efficient electroassisted photocatalytic wastewater treatment systems.