Modification strategies and applications of Mn–Cd–S solid solution-based photocatalysts

Semiconductor photocatalyzed energy production and environment treatment have received a lot of attention. Mn–Cd–S solid solutions (Mn_xCd_1−xS) with tunable band structure, suitable redox capacity, and visible light response is recognized as one of the most promising photocatalysts for practical applications. However, low separation efficiency of photogenerated carriers and sluggish reaction kinetics restricts its photocatalytic activity. This review discusses the advantages and drawbacks of Mn_xCd_1−xS for photocatalysis in terms of electronic band structure and surveys the modification strategies of photocatalytic activity, including modulation of Mn/Cd ratio, morphology/structure regulation, defect engineering, construction of heterojunction, loading cocatalysts, and integration of multiple strategies. Then, the progress in photocatalytic water splitting to hydrogen, carbon dioxide reduction, and pollutant degradation using Mn_xCd_1−xS-based materials are summarized. Finally, it is concluded by outlining the challenges and opportunities for developing efficient photocatalysts based on Mn_xCd_1−xS.