Self‐Supported Transition‐Metal‐Based Electrocatalysts for Hydrogen and Oxygen Evolution

Abstract

Electrochemical water splitting is a promising technology for sustainable conversion, storage, and transport of hydrogen energy. Searching for earth‐abundant hydrogen/oxygen evolution reaction (HER/OER) electrocatalysts with high activity and durability to replace noble‐metal‐based catalysts plays paramount importance in the scalable application of water electrolysis. A freestanding electrode architecture is highly attractive as compared to the conventional coated powdery form because of enhanced kinetics and stability. Herein, recent progress in developing transition‐metal‐based HER/OER electrocatalytic materials is reviewed with selected examples of chalcogenides, phosphides, carbides, nitrides, alloys, phosphates, oxides, hydroxides, and oxyhydroxides. Focusing on self‐supported electrodes, the latest advances in their structural design, controllable synthesis, mechanistic understanding, and strategies for performance enhancement are presented. Remaining challenges and future perspectives for the further development of self‐supported electrocatalysts are also discussed.

Multifunctional Transition Metal‐Based Phosphides in Energy‐Related Electrocatalysis

“…Besides, the self-supported electrode is quite appealing because of simplifying the electrode preparation process, avoiding the side effect of insulting binder and bringing about sustainable stability. [152] In most cases, this self-supported substrate is selected to fabricate the TMPs nanoarrays. [136a] For example, Yuan's group prepared mesoporous CoP nanorod arrays (CoP-MNA) on Ni foam through an electrodeposition method.…”

Active Electron Density Modulation of Co3O4‐Based Catalysts Enhances their Oxygen Evolution Performance

“…However, the activity and stability of those catalysts still need to be enhanced for practical applications. Unfortunately, the OER reaction involves an complex four‐electron transfer process, and most of OER catalytic materials would undergo a phase change or amorphization process due to strong polarization under oxidizing reaction environment . Therefore, it is very challenging to identify actual active sites and determine the actual rate‐determining step during the reaction process .…”

Tungsten‐Doped CoP Nanoneedle Arrays Grown on Carbon Cloth as Efficient Bifunctional Electrocatalysts for Overall Water Splitting

“…[1] Electrochemical water splitting which involves two half reactions of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is a promising technology to produce sustainable clean energy. [3] To lower the overpotentials and improve energy conversion efficiency, HER and OER electrocatalysts with high activity are necessary. [3] To lower the overpotentials and improve energy conversion efficiency, HER and OER electrocatalysts with high activity are necessary.…”