Architecting the High‐Entropy Oxides on 2D MXene Nanosheets by Rapid Microwave‐Heating Strategy with Robust Photoelectrochemical Oxygen Evolution Performance
Chae Eun Park, Raja Arumugam Senthil, Gyoung Hwa Jeong, Myong Yong Choi
Abstract
Abstract High‐entropy oxides (HEO) have recently concerned interest as the most promising electrocatalytic materials for oxygen evolution reactions (OER). In this work, a new strategy to the synthesis of HEO nanostructures on Ti 3 C 2 T x MXene via rapid microwave heating and subsequent calcination at a low temperature is reported. Furthermore, the influence of HEO loading on Ti 3 C 2 T x MXene is investigated toward OER performance with and without visible‐light illumination in an alkaline medium. The obtained HEO/Ti 3 C 2 T x ‐0.5 hybrid exhibited an outstanding photoelectrochemical OER ability with a low overpotential of 331 mV at 10 mA cm −2 and a small Tafel slope of 71 mV dec −1 , which exceeded that of a commercial IrO 2 catalyst (340 mV at 10 mA cm −2 ). In particular, the fabricated water electrolyzer with the HEO/Ti 3 C 2 T x ‐0.5 hybrid as anode required a less potential of 1.62 V at 10 mA cm −2 under visible‐light illumination. Owing to the strong synergistic interaction between the HEO and Ti 3 C 2 T x MXene, the HEO/Ti 3 C 2 T x hybrid has a great electrochemical surface area, many metal active sites, high conductivity, and fast reaction kinetics, resulting in an excellent OER performance. This study offers an efficient strategy for synthesizing HEO‐based materials with high OER performance to produce high‐value hydrogen fuel.