Rare earth doped semiconductor nanomaterials and its photocatalytic and antimicrobial activities

Abstract

Investigations on dually active rare earth doped ZnO nanomaterials for enhanced photocatalytic and anti-microbial activity were conducted. Dy3+ doped ZnO was synthesised via a co-precipitation method. The dopant concentrations were varied from 3 to 10 wt% and characterised by XRD, FT-IR, UV–vis-DRS, PL, FE-SEM, EDAX, HR-TEM, AFM, BET, XPS and EPR techniques. The prepared material was found to be in the nano regime (38–47 nm) displaying hexagonal morphology. Surface roughness was also very high (47.49 nm) as confirmed by AFM. EPR confirmed that OH radicals were generated on light irradiation. The prepared photocatalysts were investigated for Visible and UV induced photocatalytic activities for the degradation of model pollutants like OrG and MG dye. The 10DZ nanomaterial displays 99.5% of degradation of OrG, similarly more than 94% of degradation of MG was observed under UV and Visible light irradiation. The degradation of OrG and MG was carried out for standard TiO2 under UV and Visible light irradiation and the results proves that 10DZ exhibits better photocatalytic activity than TiO2. The nanomaterial was screened for its anti-microbial activities against certain species of bacterial and fungal species. 10% doped nanomaterial was found to posses excellent photocatalytic activities both under Visible and UV light irradiation. The reaction followed a pseudofirst order kinetics. The activities were far higher than undoped ZnO. The anti-microbial activities were also higher than the standard controls which proves the prepared material to act dually both as a photocatalytic and anti-microbial agent.