Phyto-synthesis of tin oxide nanoparticles using Diospyros mollis leaves extract doped graphitic carbon nitride for photocatalytic methylene blue degradation and hydrogen peroxide production

Abstract

In this study, tin oxide nanoparticles (SnO2 NPs) were combined with graphitic carbon nitride (gCN) to produce the SnO2/gCN composite for photocatalytic methylene blue (MB) degradation and H2O2 production. Specifically, SnO2 NPs were initially prepared using a biological pathway from Diospyros mollis leaves extract, followed by the incorporation on gCN via calcination treatment. Characterization of SnO2/gCN was conducted through analytical methods, including scanning electron microscopy, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, N2 sorption isotherm, photoluminescence spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS). The optical band gap of the nanocomposite was also evaluated to be 2.44 eV using the Tauc plot and UV-DRS, which is lower than pristine gCN. The photocatalytic performance over the optimal 1.0SnO2/gCN sample was resultingly investigated, reaching over 99.76 % of MB degradation efficiency within 120 min, and 4060.78 μM/g.h of H2O2 production rate under visible light radiation. Insights into the mechanism revealed the vital participation of reactive radicals, especially •O2− and •OH, in the degradation of MB molecules, while the reusability of 1.0SnO2/gCN was also maintained after 4 succeeding photocatalytic cycles. Such findings affirm the promising applicability of the constructed SnO2/gCN material in many industries, namely the environmental remediation and cleaner production sectors.