Recent progress in the design and functionalization strategies of transition metal-based layered double hydroxides for enhanced oxygen evolution reaction: A critical review

The exceptionally efficient electrochemical oxygen evolution reactions (OER) involves a sluggish four-electron transfer water splitting process that acts as a foundation for energy conversion linked with storage systems. Transition metal-based layered double hydroxides (LDH) have outstanding OER efficiency due of their capacity to modify the types and metal ratios in the interlamellar galleries, brucite like layered structure, adjustable interlayer space and abundance of basic sites. It is possible to achieve high OER efficiency in transition metal-based LDH by tuning the divalent and trivalent metal composition, which serves as electroactive sites that result in highly efficient OER processes. Transition metal-based functionalized LDH with high OER performance is increasingly being used for developing fuel cells, super-capacitors and cutting-edge technology for implementing green hydrogen. The objective of this review is to comprehend the latest developments in transition metal-based LDH for potential high-performance OER applications. A critical discussion on OER effectiveness of transition metal-based LDH based on defect engineering, hybridization, topology and linkages between structure and functionality with theoretical idea of electron transport is presented. Furthermore, challenges and potential outcomes for transition metal-based LDH-based OER processes for eco-friendly solutions in energy conversion and storage are debated which are likely to fill the knowledge gaps and open up new avenues for LDH research.