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

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.