Excellent photocatalytic performance from NiS decorated TiO2 nanoflowers with exposed {001} facets

Abstract Using some appropriate modifiers or special nano-architectures with exposed high-energy facets to design and synthesize TiO2-based heterostructures is a promising strategy, which deserves a closer study for enhancement of their photocatalytic performance. Herein, we select NiS to decorate TiO2 nanoflowers formed with exposed {001} facets for constructing NiS/TiO2 nanoflower-like p-n heterostructures by a facile hydrothermal method, and successfully apply them to the photodegradation of methyl orange (MO). It is found that the sample of 0.001-NiS/TiO2 with optimal molar ratio possesses the best photocatalytic activity, and the removal efficiency is up to 98% within 20 min with a constant degradation rate of 0.179 min-1, almost 10 times higher than that of the pure TiO2 nanoflowers (0.018 min-1). Correlation analysis suggests that the excellent photocatalytic activity of the NiS/TiO2 p-n heterostructures would stem from the synergy effects between the high efficient charge separation and transfer driven by the built-in electric field at interfaces of NiS/TiO2, and the exposed high energy {001} facets of TiO2.