Facile synthesis of Ce-doped SnO2 nanoparticles with enhanced performance for photocatalytic degradation of organic dye

Abstract

Cerium (Ce)-doped tin dioxide (SnO2) nanoparticles (NPs) have been prepared by a facile hydrothermal coprecipitation route for photocatalytic decomposition of methyl orange (MO) dye. The as-obtained NPs were characterized using different physical methods. X-ray diffraction (XRD) analysis found a rutile-phase-like crystalline structure. X-ray photoelectron spectroscopy (XPS) revealed specific energies of 486.2 eV for Sn 3d3/2 and 497.4 eV for Sn 3d5/2 and confirmed an oxidation state of Sn4+. With increasing Ce concentration (from 0% to 2% and 4%), the optical bandgap energy of the SnO2 NPs reduced (3.4–3.1 eV), resulting in a red-shift that enhanced their photocatalytic activity. The 4% Ce:SnO2 NPs exhibited superior photodegradation performance against MO organic dye, achieving 94.5% decomposition in 100 min under exposure to ultraviolet–visible (UV–Vis) light. Indeed, the photocatalytic efficiency of the 4% Ce:SnO2 NPs was 4.9- and 2.44-fold higher than that of the bare SnO2 and 2% Ce:SnO2 NPs, respectively. This outstanding photodegradation efficacy of the as-obtained 4% Ce:SnO2 NPs was due to the effective doping of Ce into the SnO2 lattice, thus preventing the recombination and allowing the effective separation/migration of photoexcited charges (e−/h+). Furthermore, improved antibacterial activity against two bacteria was clearly observed when adding Ce dopant to the SnO2 NPs.