Cadmium oxide nanoparticles doped with nickel and silver: Photocatalytic activity for environmental remediation

Abstract

In this work, we used a co-precipitation approach to create CdO nanoparticles that were co-doped with nickel (Ni) and silver (Ag). X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were employed to assess the structural attributes of the nanoparticles that were synthesized. Co-doping with Ni and Ag resulted in a steady rise in nanoparticle crystallite size, increasing from 20.97 nm to 32.16 nm. Following the co-doping procedure, FESEM pictures demonstrated a morphological shift from tiny, rock-like formations in pure CdO to bigger rock-like structures. Energy-dispersive X-ray spectroscopy (EDX) was utilised to explore the compositional characteristics of Ni and Ag-doped CdO nanoparticles. The existence of particles’ agglomerations was observed, which may have limited the real surface area available for gas adsorption and resulted in smaller apparent pore sizes in the Brunauer-Emmett-Teller (BET) investigation. Diffused Reflectance Spectroscopy (DRS) revealed a decline in the band gap from 2.45eV to 2.30eV, which was most likely caused by structural changes caused by cadmium ion replacement or the occupancy of interstitial spaces within the lattice by nickel and silver ions. The chemical and electronic states of the atoms were assessed using X-ray photoelectron spectroscopy (XPS), which examined the formation of defects in the form of oxygen vacancies, which contributed to accelerated photocatalytic performance. The deterioration of Crystal Violet (CV) dye during sunlight exposure utilising co-doped CdO nanoparticles vs pristine CdO is being evaluated in the evaluation of photocatalytic activity. Notably, co-doped nanoparticles improved photocatalytic activity significantly, with CV degradation reaching up to 95 % within 180 min of exposure. The potential of Ni and Ag impregnated CdO nanoparticles as effective photocatalysts for environmental remediation applications is highlighted in this study.