Amorphous SnO2/TiO2 heterostructures with enhanced interfacial electron coupling for enhanced photoreduction of Cr(VI)

Amorphous SnO 2 was coupled on the surface of mixed-phase TiO 2 nanoflowers (NFs) by a solvothermal synthesis. Various characteristics confirms the formation of SnO 2 /TiO 2 heterostructures. As-prepared amorphous SnO 2 /TiO 2 heterostructures revealed uniform morphology and enhanced photoelectrochemical performance. Underfull-spectrum light irradiation, the SnO 2 /TiO 2 heterostructures with an optimized SnO 2 ratio revealed the best photoreduction performance, in which Cr(VI) of 99% was removed within 30 min. This is ascribed to the introduction of amorphous SnO 2 , which adjusted the band gap structure, increased specific surface area of TiO 2 NFs, and greatly enhanced the photoelectric conversion efficiency. The mechanism of the heterostructure formation and enhanced photoreduction for Cr(VI) ions were discussed. The TiO 2 NFs with a mixture phase helps to improve the separation efficiency of photogenerated carriers. This result provides an unique idea for the construction of heterostructures.