Z‐Scheme BiOCl‐Based Photocatalysts: Recent Advances in Designing, Structural Engineering, Formation Mechanisms, and High Performance Photocatalytic Environmental Remediation

ABSTRACT The rapid escalation of environmental pollution due to industrial dyes, pharmaceuticals, pesticides, plastics, and heavy metals has emerged as a significant global challenge, demanding the formulation of effective/sustainable remediation strategies. In this context, photocatalysis, powered by abundant sunlight, has been identified as a prominent advanced oxidation process to address these challenges. Among various photocatalysts, bismuth oxychloride (BiOCl) and derivatives have gained considerable prominence due to their distinctive two‐dimensional (2D) structure/layered morphology, stability, and adjustable physicochemical properties. However, their practical applications are limited by a narrow light absorption range, rapid recombination of photo‐generated carriers, and complex defect dynamics. To overcome these, construction of direct Z‐scheme heterojunctions has been recognized as a pivotal strategy, providing enhanced visible‐light harvesting, efficient charge carrier separation, and preserved redox potentials, akin to natural photosynthesis. This review systematically summarizes recent advancements in synthesis, engineering, and modification of BiOCl‐based Z‐scheme photocatalysts, focusing on property tailoring and heterojunction assembly. Their environmental applications are extensively discussed, highlighting effective removal of various contaminants, including industrial organic pollutants, pharmaceuticals, pesticides, herbicides, toxic heavy metals, emerging plastic waste, etc. Notably, BiOCl‐based Z‐scheme photocatalysts demonstrate up to severalfold (typically 2–6 times) enhancements in photodegradation rates compared to pristine materials. Additionally, the mechanistic insights into Z‐scheme charge transfer, role of oxygen vacancies, reactive oxygen species generation, etc. are critically examined. The review also addresses current challenges that is stability, scalability, mechanistic ambiguities, etc. while outlining future research directions. By linking structure–activity relationships with emerging applications, it provides a comprehensive framework for the rational design of next‐generation BiOCl‐based Z‐scheme photocatalysts aimed at sustainable environmental remediation.