Photocatalytic degradation of naphthalene using tin dioxide nanomaterial under visible light

Abstract

Coal processing in the refinery industry often lead to the formation of coal tar containing polycyclic aromatic hydrocarbons which are likely to affect human and animal health when released in surface and ground waters. A study was conducted to investigate the photocatalytic property of tin dioxide in an attempt to degrade a polycyclic aromatic hydrocarbon namely naphthalene. The tin dioxide nanomaterial was prepared using the sol-gel method and calcination at 500°C. The synthesised photocatalyst was characterised using techniques such as Fourier Transformed Infra-Red (FTIR) spectroscopy, scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) to determine the active groups, the morphology and the elemental composition respectively. The synthesised tin dioxide was then exposed to naphthalene under visible light and the effects of dosage and time on the degradation performance was assessed. The effect of oxidant on the photocatalytic activity of tin dioxide. It was found that 82% of naphthalene could be removed from the solution using a dosage of 40 mg of SnO2 . The degradation of naphthalene could be predicted using Langmuir-Hinshelwood kinetic model resulting in a kinetic rate constant of 0.019 min-1