Highly efficient photocatalytic MO degradation by ZnCdS composite photocatalyst modified with MgTi2O5

Abstract

Recently, ZnCdS has become an attractive visible-light-driven photocatalyst due to its tunable band gap and suitable band edge position. However, fast recombination of photo-generated carriers in ZnCdS still restricting its industrial application. In this paper, a novel and high-efficiency MgTi₂O₅/ZnCdS composite was constructed by in situ growth of ZnCdS nanoparticles on MgTi₂O₅. The photocatalytic activity of the Mg₂TiO₅/ZnCdS composite was evaluated using methyl orange (MO), tetracycline (TC), and methylene blue (MB). The results show that the as-prepared hybrid exhibited highly efficient photocatalytic activity under visible light irradiation, and the degradation efficiencies in 1 h reach about 93 %, 96.2 % and 94.5 % for MO, TC and MB, respectively, while the pure ZnCdS show only 60 % degradation efficiency under the same conditions, respectively. The improved photocatalytic activity could be attributed to the high efficient charge separation and fast charge transport in the MgTi₂O₅/ZnCdS composite, which are mainly due to the built-in electron field formed at the joint of the Mg₂TiO₅/ZnCdS heterojunction.