Natural sunlight assisted photocatalytic removal of methylene blue and crystal violet dyes using Ni doped tin oxide nanostructures synthesized via chemical and green route

In the present work, Ni-doped SnO2 nanoparticles with varying doping concentration were synthesized by adopting two processing routes. X-ray diffraction (XRD) study confirmed the tetragonal rutile structure of chemical and green synthesized Sn1-xNixO2 (x = 0.5, 1.5 & 2.5%) nanoparticles. FE-SEM micrographs exhibited significant variations in morphology leading to the formation of spherical nanoparticles with agglomeration via chemical route while tiny rods were observed in case of green route. Optical bandgap (E-g) found to decrease with doping concentration irrespective of the processing technique. The obtained outcomes from XPS studies confirmed the presence and oxidation states of desired elements in the samples. Methylene blue (MB) and crystal violet (CV) were selected as target pollutants in order to investigate the photocatalytic performance under natural solar light illumination. The better catalytic performance has been achieved by green synthesised Sn1-xNixO2 nanoparticles with the higher degradation efficiency of 95.2% as compared to chemical synthesised SnO2 nanoparticles (80%) under natural solar light. The obtained results showed that doping and processing methods have significant impact on the structural, optical, morphological and photocatalytic performance of nanoparticles.