Preparation and characterization of Ni-doped ZnO–SnO2 nanocomposites: Application in photocatalysis

•Ni-doped ZnO–SnO2 nanocomposites were prepared from hydrothermal method.•Structural and optical properties of Ni-doped ZnO–SnO2 nanocomposites were investigated.•The presence of nickel impacts more specifically the optical parameters of ZnO nanoparticles.•High photocatalytic activity of ZnO–SnO2 nanoparticles is seen under UV or visible light irradiation.

The paper reports on the synthesis of nickel-doped ZnO–SnO2 nanocomposites with a molar ratio Zn:Sn of 2:1 using the hydrothermal method followed by calcination at 700 °C. The resulting nanocomposites were characterized using X-ray diffraction (XRD) patterns, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and Energy-dispersive X-ray spectroscopy (EDX). The results revealed that the Ni/ZnO–SnO2 material consists of aggregated cassiterite SnO2 and wurtzite ZnO nanoparticles (NPs) with a size ranging from 14 to 40 nm. Furthermore, they show that Ni adding induces a dominant effect on the optical, structural and morphological properties of ZnO–SnO2 NPs. The photocatalytic behavior of the synthesized nanocomposites is investigated using rhodamine B (RhB) as model organic pollutant. A maximum degradation efficiency of 96% is achieved under visible light irradiation. While nickel doping did not enhance the photocatalytic activity of ZnO–SnO2 NPs, the photocatalytic performance of Ni/ZnO–SnO2 NPs is much higher than that of Ni-doped ZnO NPs. The photodegradation mechanism is believed to occur through photosensitization.