Constructing trinary heterostructure of TiO2/CoCr2O4/SrTiO3 to enhance photocatalytic activity toward degradation of yellow 28 dye

Abstract

Today, the design of efficient visible light-driven photocatalytic systems for the degradation of organic dyes is of great interest in human health and environmental protection. Constructing heterostructured nanocomposites using coupling metal oxide semiconductors with visible-light-responsive photocatalytic materials is an effective strategy to improve the photocatalytic potential. For this purpose, a trinary TiO2/CoCr2O4/SrTiO3 hetero- structured photocatalyst with enhanced visible-light photocatalytic activity was fabricated using the intimate interfacial contact of TiO2/SrTiO3 nanotubes with CoCr2O4 nanoparticles. Compared with single or binary photocatalysts, trinary TiO2/CoCr2O4/SrTiO3 nanocomposite demonstrated enhanced photocatalytic activity and cycling stability in the degradation of basic yellow 28 (BY28) dye under visible-light irradiation. The optimal TiO2/CoCr2O4/SrTiO3 nanocomposite degraded almost 99% of BY28 under visible light in 2 h, compared to approximately 37%, 66%, and 71% for the SrTiO3 nanorods, CoCr2O4 nanoparticles, and TiO2 nanotubes, respectively. This superior photocatalytic performance can be ascribed to the synergistic effects of elevated photon absorption, charge transfer, and efficient charge separation. In addition, the probable mechanism for the degradation of BY28 dye over TiO2/CoCr2O4/SrTiO3 nanocomposite is also elucidated using PL and active species scavenger studies