Photocatalytic activation of Ag-doped SrSnO3 nanorods under visible light for reduction of p-nitrophenol and methylene blue mineralization

Abstract

The utilization of solar energy for the treatment of wastewater pollutants by photocatalysts has been considered a promising solution to address environmental problems. Herein, we have synthesized silver nanoparticle-doped strontium stannate (Ag-doped SrSnO3) nanorods by hydrothermal method followed by ultrasonic treatment. The developed nanocomposites were applied for photocatalytic reduction of p-nitrophenol (4-NP) and methylene blue (MB) mineralization under visible light illumination. The effect of hydrothermal duration time (16–25) h, Cetyltrimethylammonium bromide (CTAB) and silver nanoparticles (Ag NPs) concentration (0.5–2.5) wt% on the crystal, surface, optical, photoluminescence as well as photocatalytic activity were studied. A well-defined crystalline cubic phase of SrSnO3 was obtained. CTAB inhibits the crystal growth of SrSnO3. Reduction of 4-NP and MB mineralization were used as two-model reactions for testing the effect of Ag doping concentration on the photocatalytic activities of Ag/SrSnO3 under visible light illumination. The obtained results show that 2.0 wt% of Ag-doped SrSnO3 exhibits efficient photocatalytic reduction of 4-NP with 98.2% conversion within 5 min of reaction time. Also, 87% of the MB sample was mineralized after 1 h of visible illumination using 2.0% Ag/SrSnO3 in the presence of H2O2. Besides, we have discussed the possible photocatalytic mechanism for reduction of 4-NP and mineralization of MB using 2.0 wt% of Ag doped SrSnO3 under visible light illumination.