Waste to wealth: direct utilization of spent materials for electrocatalysis and energy storage

The pursuit of carbon neutrality in today's world has led to the development of environmentally friendly, sustainable energy sources. The conversion of waste into wealth in electrocatalysis and energy conversion and storage not only mitigates environmental pressure but also provides valuable electrode materials for the energy crisis with comprehensive economic benefits. Herein, a comprehensive review of the recent advances in transforming spent materials into highly active species in energy related fields is presented, focusing on versatile waste sources, synthetic strategies, structural properties, electrochemical performances, and applications in clean sustainable energy fields. Firstly, we provide a brief description and discussion of the synthetic methods employed in the transformation of waste. Secondly, waste materials containing precious metals, carbon sources, heteroatoms, and interlinked structures that are treated using different synthetic strategies for reutilization in various electrocatalysis are systematically discussed. Thirdly, by taking full advantage of the rich porosity, high surface area, multiple electron transport channel and high conductivity, these spent materials are substantially employed as highly efficient materials in energy conversion and storage systems which are classified into various types of batteries and supercapacitors. Finally, the challenges and prospects for green and sustainable resources in the burgeoning field of waste to wealth utilization in energy conversion and storage are proposed.