SCAN Dodzi ZIGAH 11/04/25

High-Entropy Oxide as a New Class of Photoelectrocatalysts for Water Splitting

High-entropy oxides (HEOx) constitute a new class of materials that have attracted increasing interest over the past decade. By incorporating multiple cations into a single crystalline lattice, they achieve high configurational entropy (ΔS_config). This high entropy, combined with the presence of oxygen vacancies, can significantly enhance the mobility of charge carriers, leading to improved catalytic performance. Moreover, these materials exhibit exceptional thermal, chemical, and structural stability, making them highly suitable for a variety of catalytic and functional applications. Despite these advantages, HEOx materials have been relatively unexplored, especially in the field of photoelectrocatalysis. In this study, (CoNiFeCuZn)WO₄ and (MgCuCoNiZn)O were synthesized using a top-down approach and thoroughly characterized using various techniques to investigate its structural and optical properties. Their electrocatalytic activity toward the oxygen evolution reaction (OER) was evaluated using cyclic voltammetry and linear sweep voltammetry (LSV), which revealed a relatively high catalytic performance. Moreover, the visible-light band gap of these materials strongly suggests their potential for solar-driven water splitting. Modeling and preliminary photocatalytic results further indicate the possibility of using these materials to generate H₂ under illumination, making them promising candidates for future sustainable energy conversion applications.

Figure 1 : (left), Schematic representation of water splitting by photocatalysis on HEO , (right) LSV on (CoNiFeCuZn)WO₄