Preparation and Photocatalytic Hydrogen Production of TiO ₂ /(AlMnCoNiZn) ₃ O ₄ Nanocomposites

Photocatalytic water splitting is a promising strategy for addressing the global energy crisis and environmental pollution. In this study, spinel‐type high‐entropy oxide (HEO) nanoparticles, (AlMnCoNiZn) ₃ O ₄ , were successfully synthesized via a solution combustion method. TiO ₂ /(AlMnCoNiZn) ₃ O ₄ nanocomposites with varying molar ratios were subsequently fabricated through solid‐state sintering, and their photocatalytic water‐splitting performance was systematically investigated. The hydrogen production rate initially increased and then decreased with increasing TiO ₂ content. The optimal nanocomposite achieved a hydrogen evolution rate of 1450 μmol·h ⁻¹ ·g ⁻¹ under simulated sunlight irradiation, which is 2.2 times higher than that of pure TiO ₂ nanoparticles. In addition, the TiO ₂ /(AlMnCoNiZn) ₃ O ₄ nanocomposites exhibited significantly improved photocorrosion resistance compared with TiO ₂ nanoparticles. After 12 h irradiation under a 500‐W high‐pressure mercury lamp, the hydrogen production rates of the nanocomposites and pure TiO ₂ retained 79.3% and 5.47% of their initial values, respectively. These results demonstrate the important role of (AlMnCoNiZn) ₃ O ₄ and other HEOs in enhancing the photocatalytic performance of nanoheterojunction catalysts. Furthermore, this work broadens the potential applications of (AlMnCoNiZn) ₃ O ₄ and related HEO materials in the field of photocatalysis.