Layered double hydroxides derived from waste for highly efficient electrocatalytic water splitting: Challenges and implications towards circular economy driven green energy

Waste from industry is inexpensive and has a great capacity for storage but because of heavy metal leaching, it also significantly harms the environment. On the other side, electrolytic water splitting could be used to produce green hydrogen in a sustainable manner. The objective of this review is to critically analyze the waste-derived layered double hydroxides (LDH) production, emphasizing their utility in efficient electrochemical water split-ting for generation of green hydrogen as sustainable energy. The broad idea of water electrolysis, its design methodologies are critically studied involving waste-derived LDH and waste-derived functionalized LDH, fol-lowed by a representation of current waste transformation strategies. The relationship between the framework and the effectiveness of waste-derived LDH is also discussed. This review further highlights the mechanistic pathways of electrocatalytic water splitting and also emphasizes the application of waste-derived LDH for circular economy-based sustainable development of green hydrogen. The challenges and future directions in this rapidly evolving subject are also critically discussed. It is envisaged that this critical review would offer insightful information on the design strategies and applications of waste-derived LDH electrocatalysts for the generation of green hydrogen based on circular economy.