Enhancement of photocatalytic properties of TiO2 nanobelts through surface-coarsening and surface nanoheterostructure construction

In this work, heterostructures were obtained by uniformly assembling NiO nanoparticles on the surface-coarsened TiO2 nanobelts through a precipitation process. The uniform assembling of NiO nanoparticles led to a large number of nano-p–n-junction heterostructures on the surface of the TiO2 nanobelts, where NiO and TiO2 are p- and n-type semiconductors, respectively. Compared with both pure NiO nanoparticles and TiO2 nanobelts, NiO nanoparticles/TiO2 surface-coarsened nanobelt heterostructured composite exhibited a greatly enhanced photocatalytic activity in the decomposition of a model dye compound methyl orange under ultraviolet light irradiation. It was argued that the nano-p–n-junctions effectively reduce the recombination of electrons and holes, thus resulting in enhanced photocatalytic property of the heterostructured composites. The better performance of the surface-coarsened nanobelts is due to the increased photo absorption and production of charge carriers, which renders the composites with further enhanced photocatalytic performance. The established approach allows the control of the nano-p–n junction heterostructure on the nanobelts, and hence, their photocatalytic effect.