Influence of Bi3+ doping on structural, optical and photocatalytic degradation properties of NiWO4 nanocrystals

Pristine and Bi3+doped NiWO4 nanoparticles are synthesized by direct chemical precipitation method. The structural and optical properties are investigated using various characterization techniques. Optical absorption studies confirm dual direct-indirect bandgap nature of pure and Bi3+ doped NiWO4 nanoparticles. Doping with Bi3+ ion modifies the structural and optical parameters of NiWO4 sample. These variations in parameters influence the luminescence and photocatalytic properties of NiWO4 nanoparticles. The lowest doping concentration of Bi3+ leads to high PL emission and this property can be used in luminescence applications. The higher concentration of Bi3+ ions leads to the quenching of PL. The sample with the highest dopant concentration shows the lowest PL intensity and improved photocatalytic activity. Indirect chemical probe method reveals that OH.is the main active species involved in the photocatalytic decolouration of dyes. The degradation of dyes follows pseudo-first-order kinetics. Current work constitutes the first report on the effect of Bi3+ doping on the structural and optical properties, and photocatalytic activity of NiWO4 nanoparticles.