Enhanced Photocatalytic Activity of Co Doped SnO2 Nanoparticles for the Degradation of Rhodamine B

Abstract

The increasing growth of the textile industry in Indonesia also contributes to environmental pollution due to textile dye pollutants. This research aims to synthesize tin dioxide (SnO₂) semiconductor doped with cobalt (Co) using the sol-gel method to improve its photocatalytic performance in degrading Rhodamine B dye. The synthesis involves varying Co doping concentrations (0.4 mmol, 0.6 mmol, and 0.8 mmol) with the addition of 1 mL of diethanolamine (DEA) as an additive. Characterization using UV-DRS spectroscopy shows a decrease in the band gap energy of SnO₂ from 3.455 eV to 1.910 eV after being doped with Co²⁺ ions at an optimum doping concentration of 0.8 mmol. SEM analysis confirmed the spherical morphology and uniform distribution of the synthesized nanoparticles. Photocatalytic tests showed that Co-doped SnO₂ (0.8 mmol) achieved 65.43% degradation of Rhodamine B in 90 minutes under UV light, compared to 24% for undoped SnO₂ in 120 minutes. These findings demonstrate that Co doping significantly improves the photocatalytic efficiency of SnO₂, offering a potential semiconductor-based solution to reduce textile dye pollutants and reduce environmental pollution.