Heterostructured YFeO3/CeO2 as efficient photoelectrode for photoelectrochemical degradation of organic pollutants under visible light irradiation

Abstract

A YFeO3/CeO2 catalyst is developed using a sol-gel procedure to overcome the recombination of photogenerated electron–hole pairs, which limits its degradation efficiency. The YFeO3/CeO2 catalyst is characterized by two distinct orthorhombic YFeO3 and CeO2 phases, with the size of YFeO3 crystal smaller than that of its parent phase. YFeO3/CeO2 with a higher CeO2 content (YC-30) reveals not only a porous morphology and hydrophilicity, but also a reduced energy bandgap (1.74 eV) that is lower than that of either single YFeO3 (1.90 eV) or CeO2 (2.86 eV). In the photocatalysis assessment of the YC-30 electrode, a high photocurrent density of up to 156.3 μA cm−2 at 1.4 V (vs. Ag/AgCl) under simulated sun irradiation is achieved. Furthermore, the YC-30 electrode achieves a favorable photoelectrocatalytic efficiency of 75.2 % under visible light irradiation for Reactive Black 5 dye degradation, which is better than those of the YFeO3 (31.9 %) and CeO2 (46.9 %) electrodes. The improved degradation performance of the YC-30 catalyst can be attributed to its smaller crystallite size, porous structure, and a certain amount of YFeO3/CeO2 heterojunction, which is conducive to the separation of electron–hole pairs owing to electron diffusion driven by the difference in electron density between YFeO3 and CeO2.