High-entropy spinel oxide: Synthesis and photo-responsivity of Mn_0.68Cr_0.8Rh_0.64Co_0.87O₄

Recently, there has been extensive research on modulating band structures using MnCr₂O₄, which has gained significant attention as a photocatalyst. However, due to thermodynamic constraints, conventional modulation of band structures using two compositions poses challenges. Therefore, we utilized a high-entropy approach to easily modulate band structures by forming multi-composition systems (three-composition oxides or higher). The spinel structure of Mn_0.68Cr_0.8Rh_0.64Co_0.87O₄ produced via electrospinning enabled the fabrication of nano fibers with an average diameter of 160 nm at a calcination temperature of 900 °C, and these nano fibers were crystallized through various analytical instruments. Furthermore, nanofibers calcined at 900 °C exhibited high responsivity and fast rise, decay times under a light source with a wavelength of 635 nm. Thus, with such high reactivity, fast response time, and clear selectivity, Mn_0.68Cr_0.8Rh_0.64Co_0.87O₄ indicates promising potential as a material for future photo-catalytic research.