The coupling effect of functional bipartite hetero-interfaces accelerated TiO2-based photocatalysis

Abstract

TiO2 is a promising environmental remediation photocatalyst that mitigates environmental damage and addresses energy needs by improving the removal efficiency of pollutants from mixed wastewater. To break the technical bottleneck of low visible light utilization and high carrier recombination efficiency of traditional TiO2, a photocatalyst MMT@Cu2+-Fe3O4/TiO2 (M-Cu/FT) with functional bipartite hetero-interfaces was prepared via a two-step water bath reflux method. Ordered self-assembly Cu2+-Fe3O4/TiO2 hetero-interfaces are growing along the edge of MMT with positive potential. MMT@Cu2+-Fe3O4 hetero-interfaces and Cu2+-Fe3O4/TiO2 hetero-interfaces are regarded as independent workstations for electron enrichment and hole retention, respectively, which are equipped with Al-O-Fe(Cu2+) and (Cu2+)Fe-O-Ti bonds that can be served as carrier transport channels to construct intelligently tunable oxidation/reduction systems. The Cu2+ doping not only induces the generation of a built-in electric field by causing lattice distortion to accelerate carrier separation but also constructs traps in the valence band at the hetero-interfaces to facilitate hole trapping. It is demonstrated that M-Cu/FT is beneficial for Rh-B degradation and Cr(VI) reduction in the aqueous phase under visible irradiation, whereas the treatment efficiency of mixed wastewater can reach up to 97%, which is an appealing tendency for high-value utilization of green energy.