Recent advances in photocatalytic multivariate metal organic frameworks-based nanostructures toward renewable energy and the removal of environmental pollutants

Abstract

Water pollution and energy crises are major problems for the sustainability of the modern world. Solar energy–driven photocatalysis technique is a promising environmental remediation approach. Multivariate metal-organic frameworks (MTV-MOFs) have recently emerged as an exciting class of crystalline materials with flexible tunability in porous structure and composition, rich topology, enhanced surface area, and broad visible-light absorption. The modularity of MOFs can be achieved by altering metal clusters and carbon-containing organic linkers in orderly repeating two- or three-dimensional arrangement. This review presents a discussion on recent advances in MTV-MOFs–based photocatalysis targeted for pollutant degradation, CO2 reduction, and water splitting. The advantages of MTV-MOFs for diverse photocatalytic applications include structural modulation, functionalized adjustability, and synthesis selectivity of mixed-linker/metal (ML/MM) coordinative bonds. The synthesis methodologies, that is, one-step and postsynthetic routes, have been elaborated for ML/MM MOFs to obtain improved photocatalytic activity. The photocatalytic mechanism, followed by MTV-MOFs heterostructures with metal oxides or carbonaceous semiconductors, was discussed in detail. The discussion is concentrated on structural and topological features via self-assemble of linkers and metal ions in ML/MM MOFs. The future research area should select suitable metal ions/linkers, rational synthesis, and appropriate photocatalytic mechanism of orderly MTV-MOFs.