Optimization elements ratio of oxides (Fe-Co-Ni-Cu-Zn-O) for enhanced photocatalytic hydrogen evolution and degradation of rhodamine B

High entropy oxides (HEOs), typically composed of elements in equimolar ratios, were synthesized via a solvothermal method followed by thermal annealing. This study uniquely highlights the impact of tailoring element ratios on HEOs properties, including structural stability , optical behavior, and electrochemical performance . An HEO with enhanced photocatalytic hydrogen evolution and organic pollutant degradation capabilities was developed through systematic composition adjustments. X-ray diffraction confirmed the formation of new oxides , with interactions between them significantly improving photocatalytic efficiency. The formation of the new oxide transformed the original equimolar HEO into a composite oxide. The electrochemical analysis demonstrated that non-equimolar oxides exhibit superior charge transfer rates and hydrogen evolution activity, overcoming the limitations of conventional HEOs. Adjusted compositions also tuned the band gap, enabling better visible light absorption . Notably, cyclic tests confirmed these oxides' excellent structural stability and reusability , highlighting their potential as advanced, durable photocatalysts . This work emphasizes the critical role of metal interactions in driving performance enhancements and advancing photocatalyst design. • The element ratios of composite oxides significantly affect structural and electrochemical properties. • Composite oxides were synthesized using a solvothermal method and thermal annealing. • Varied compositions of oxides were applied in photocatalytic hydrogen evolution reactions. • Adjusting element ratios improved charge transfer rates and hydrogen evolution activities. • Cyclic tests showed composite oxides maintained excellent structural stability and reusability.