Noble metal-free 0D-1D NiS/CdS nanocomposites toward highly efficient photocatalytic contamination removal and hydrogen evolution under visible light.

The development of stable noble metal-free photocatalysts with efficient separation and transportation of the photogenerated electrons-holes is of crucial importance for promoting the application of photocatalysis technology. Herein, we propose an electron transfer strategy by reasonable design and fabrication of novel 0D NiSx nanosheets as a co-catalyst on the surface of 1D CdS nanorods (CdS-NRs) to enhance photocatalytic hydrogen evaluation and contamination (Cr(vi), rhodamine B and bisphenol A) removal in water. Under visible light irradiation, the 0D-1D NiSx/CdS-NR nanocomposite with 1.5% NiSx loading gave a hydrogen evolution rate of 5.98 mmol h-1 g-1, which is about 5.3 times and 1.9 times higher than that of the native CdS-NRs and the optimal 1% Pt/CdS-NRs, respectively. Notably, good stability in the recycling test and a high apparent quantum efficiency of about 69.9% at 420 nm were also obtained. The 1.5% NiSx/CdS-NRs exhibited enhanced photocatalytic contamination degradation efficiency of about 2 times higher than pure CdS-NRs. In this hybrid photocatalyst, 0D NiSx nanosheets came into intimate interfacial contact with the surface of 1D CdS-NRs and played a similar role as noble metals, which could effectively improve the separation, transportation efficiencies and lifetime of photogenerated charge, and thus enhance the photocatalytic performance of CdS-NRs with more efficient conversion of solar energy. This work shows not only a possibility for the utilization of noble metal-free NiSx as a co-catalyst in the photocatalysis, but also provides new insight into the design and fabrication of high-performance composite photocatalysts (such as NiSx/g-C3N4 and NiSx/Zn3In2S6).