Controlled Synthesis and Structure Engineering of Transition Metal‐based Nanomaterials for Oxygen and Hydrogen Electrocatalysis in Zinc‐Air Battery and Water‐Splitting Devices

Abstract

Electrocatalytic energy conversion plays a crucial role in realizing energy storage and utilization. Such as water electrolysis, fuel cells, and metal air batteries, clean energy devices heavily depend on a series of electrochemical redox reactions occurred on the catalysts surface. Therefore, developing efficient electrocatalysts is conducive to remarkably improved performance of these devices. Among numerous studies, transition metal‐based nanomaterials (TMNs) have been considered as the promising catalysts by virtue of their abundant reserves, low cost, and well‐designed active sites. This minireview follows with interest the typical clean electrochemical reactions: hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). We describe the recent efforts to optimize the external morphology and the internal electronic structure of TMNs. Begin with the research of single‐component TMNs, the active sites are clarified, and strategies for exposing more active sites are discussed. The summary about multi‐component TMNs demonstrates the complementary advantages of integrating functional compositions. Later, a general introduction of single‐atom TMNs is provided to deeply understanding of the catalytic process at atomic scale. At the end of this paper, we summarize the current challenges and the development trends of TMNs in the clean energy devices.