Investigation of α-Fe2O3 catalyst structure for efficient photocatalytic fenton oxidation removal of antibiotics: preparation, performance, and mechanism

Abstract

Currently, the surface structure modification of photocatalysts is one of the effective means of enhancing their photocatalytic efficiency. Therefore, it is critically important to gain a deeper understanding of how the surface of α-Fe₂O₃ photocatalysts influences catalytic activity at the nanoscale. In this work, α-Fe₂O₃ catalysts were prepared using the solvothermal method, and four distinct morphologies were investigated: hexagonal bipyramid (THB), cube (CB), hexagonal plate (HS), and spherical (RC). The results indicate that the hexagonal bipyramid (THB) exhibits the highest degradation activity towards tetracycline (TC), with a reaction rate constant of k = 0.0969 min⁻¹. The apparent reaction rate constants for the cube (CB), hexagonal plate (HS), and spherical (RC) morphologies are 0.0824, 0.0726, and 0.0585 min⁻¹, respectively. In addition, it has been observed that the enhancement of photocatalytic activity is closely related to the increase in surface area, which provides more opportunities for interactions between Fe²⁺ and holes. The quenching experiments and electron paramagnetic resonance (EPR) results indicate that the ˙O², ˙OH and h⁺ contribute mainly to the degradation of TC in the system. This research contributes to a more comprehensive understanding of catalyst surface alterations and their impact on catalytic performance.