Recent advances in zeolitic imidazole frameworks based photocatalysts for organic pollutant degradation and clean energy production

To address the global energy crisis and widespread environmental deterioration issues, semiconductor photocatalysts have been widely recognized and studied. In this direction, new-age materials as zeolitic imidazolate frameworks (ZIFs), belonging to a sub-class of metal-organic frameworks (MOFs) have piqued the interest of researchers as prospective photocatalyst candidates. With huge specific surface area, tuneable porosity, diverse structure, ease of designing and controllable properties, ZIFs are highly sought-after material for pollutant degradation and clean energy generation. Additionally, ZIFs may undergo thermal processing to produce functional substances with similar structural characteristics but improved light responsiveness and electron transfer abilities. Numerous functional materials and better photocatalysts can be prepared by thermal treatment of ZIFs, formation of composites, heterostructures with other semiconductors or electron mediators which may have similar structural characteristics but better light capture abilities, charge transfer capabilities and strong redox properties. This paper carefully summarizes and analyses the applications of ZIFs based photocatalysts for photocatalytic organic pollutant degradation, hydrogen generation and CO₂ conversion. A sincere attempt has been made to lay down mechanistic insights into synergism of the structural and electronic properties of ZIFs with other catalyst counterparts for superior photocatalytic performance with focus on band structure analysis, charge transfer mechanisms and performance. Finally, the achievements, novelties and bottlenecks have been discussed and future research directions have been proposed.