Designing and modification of bismuth oxyhalides BiOX (X = Cl, Br and I) photocatalysts for improved photocatalytic performance

Photocatalysis has emerged as a promising technology for solving global environmental and energy challenges. The selectivity of low-cost, non-toxic and thermochemically stable materials for photocatalytic applications is crucial to meet the industrial standards. Despite of owing unique layered structure, distinct electronic band structure and tunable optical properties, the bismuth oxyhalides BiOX (X = Cl, Br and I) photocatalytic materials suffer from rapid recombination of charge carriers and limited light absorption issues. These limitations restrict the photocatalytic efficiency and industrial applications of BiOX materials. The focus of this critical review is to discuss recent developments in the design and modification of existing and new BiOX materials for getting optimum photocatalytic response from these materials. The key elements of the review are BiOX synthesis methods, BiOX driven water splitting, single and double stage hydrogen evolution systems, degradation of organic pollutants and trends of boosting the photocatalytic efficiency of the BiOX materials. Finally, this insight discusses the existing issues and future perspectives of BiOX photocatalysts.