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

Gadolinium and iron doped LaNiO 3 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 LaNiO 3 . 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 LaNiO 3 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 LaNiO 3 . The antibacterial activity of the undoped LaNiO 3 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. • Gd and Fe substituted LaNiO 3 perovskite oxides were fabricated by facile micro-emulsion approach. • Doping of Gd and Fe affected the photocatalytic and the antimicrobial properties. • Photocatalytic activity was evaluated using RhB dye and 89.3% degradation versus 33.5% for LaNiO 3 . • The perovskite oxides showed promising potential for harvesting solar light for catalytic applications.