Band gap tuning by Gd and Fe doping of LaNiO3 to boost solar light harvesting for photocatalytic application: A mechanistic approach

Abstract

Gadolinium and iron doped LaNiO3 perovskites were prepared via facile micro-emulsion approach and characterized using various techniques. A single-phase distorted rhombohedral geometry was obtained with effective doping of Gd and Fe ions in LaNiO3. Photoluminescence spectra show the decrease in intensities on Gd and Fe doping. The energy band gap values decreased from 2.85 to 2.21 eV by doping. The photocatalytic activity (PCA) of undoped and doped LaNiO3 was evaluated by the degradation of RhB under sunlight irradiation. Gd and Fe doped NPs shows about 89.3% degradation of RhB with 90 min versus 33.5% for LaNiO3. The antibacterial activity of the undoped LaNiO3 and Gd and Fe doped NPs were examined against Bacillus cereus (B, cereus), Escherichia coli (E. coli) Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis), which shows remarkable antibacterial activities. The antifungal activity was improved by doping against Green fumigates, penicillin and Black niger. Molecular docking studies were performed with ligand (La–Gd Ni–CeO) and GerK3, GerBC and FtsZ receptor protein of B. megaterium and B. subtilis exhibited a reliable binding affinity towards microbial proteins. Results reveals that the Gd and Fe doped material annealed at 950 °C have narrow band gap and revealed a probable catalytic application under visible light exposure.