Interfacial S-Scheme-Based Bi2WO6/ZIF-8@ZIF-67 Heterojunction for Enhanced Chlorpyrifos Remediation under Natural Sunlight Using RSM-CCD Approach

Chlorpyrifos (CP), a persistent organophosphate pesticide detected in various water sources, requires advanced remediation strategies to mitigate its toxicological impacts. In this study, Bi2WO6/ZIF-8@ZIF-67, a ternary heterojunction, was developed via sol–gel combined hydrothermal method. Photocatalytic performance under natural sunlight demonstrated ∼92% removal of 100 mg L–1 CP by using 50 mg of catalyst within 75 min, while RSM CCD optimized the efficiency to 88% for 90 mg L–1 of CP by using 45 mg of catalyst within 70 min. The enhanced photocatalytic performance can be attributed to improved visible light absorption and efficient interfacial charge transfer arising from S-scheme heterojunction formation between Bi2WO6 and ZIF-8@ZIF-67. The scavenger study identifies hydroxyl and superoxide radicals as the primary reactive species. The catalyst retained ∼88% efficiency over five successive cycles and exhibited low phytotoxicity toward black gram seeds demonstrating its potential relevance for sustainable environmental and agricultural applications.