CdS/LaFeO3 heterojunctions with improved optical properties for visible-light catalytic applications

Construction of heterojunctions is a normal and effective strategy to improve the photocatalytic performances of semiconductors, through which both the lifetime and the redox ability of electrons/holes can be improved, as compared to the respective component. On this basis, we constructed Z-scheme CdS/LaFeO3 heterojunctions (CdS/LFO), by in-situ growing different amounts of CdS on the surface of LaFeO3, for photocatalytic degradation of tetracycline hydrochloride (TC) in aqueous solution at room temperature. The crystal structure, surface morphology and optoelectronic properties of the CdS/LFO heterojunctions were systemically characterized to correlate the reaction activity. Photocatalytic tests indicate that the CdS/LFO heterojunctions exhibit promising activity for TC degradation under visible light irradiation (λ ≥ 420 nm), with 85% TC conversion obtained at reaction time of 45 min, which is 3.4 and 1.9 times higher than that of CdS and LaFeO3. The CdS/LFO heterojunctions are also stable in the reaction and can be reused for four cycles with no appreciable activity loss. The applicability of CdS/LFO to photocatalytic degradation of organic dyes, as well as the reaction mechanism, was also explored.