Subtle 2D/2D MXene‐Based Heterostructures for High‐Performance Electrocatalytic Water Splitting

Abstract

Developing efficient electrocatalysts is significant for the commercial application of electrocatalytic water splitting. 2D materials have presented great prospects in electrocatalysis for their high surface‐to‐volume ratio and tunable electronic properties. Particularly, MXene emerges as one of the most promising candidates for electrocatalysts, exhibiting unique advantages of hydrophilicity, outstanding conductivity, and exceptional stability. However, it suffers from lacking catalytic active sites, poor oxidation resistance, and easy stacking, leading to a significant suppression of the catalytic performance. Combining MXene with other 2D materials is an effective way to tackle the aforementioned drawbacks. In this review, the focus is on the accurate synthesis of 2D/2D MXene‐based catalysts toward electrocatalytic water splitting. First, the mechanisms of electrocatalytic water splitting and the relative properties and preparation methods of MXenes are introduced to offer the basis for accurate synthesis of 2D/2D MXene‐based catalysts. Then, the accurate synthesis methods for various categories of 2D/2D MXene‐based catalysts, such as wet‐chemical, phase‐transformation, electrodeposition, etc., are systematically elaborated. Furthermore, in‐depth investigations are conducted into the internal interactions and structure‐performance relationship of 2D/2D MXene‐based catalysts. Finally, the current challenges and future opportunities are proposed for the development of 2D/2D MXene‐based catalysts, aiming to enlighten these promising nanomaterials for electrocatalytic water splitting.

Hierarchically Structured Graphene Aerogel Supported Nickel–Cobalt Oxide Nanowires as an Efficient Electrocatalyst for Oxygen Evolution Reaction

“…Electrochemical water splitting, including two half-reactions of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), has attracted attention for producing hydrogen gas. Especially, the OER electrolysis is deemed to be a promising strategy for the formation of clean energy and energy conversion [4][5][6]. However, it is emergent to dissolve the issue of sluggish kinetics and complicated reactions during the OER process, which determines its faradic efficiency and requires a high overpotential to satisfy the practical applications [7].…”