Novel ZnTi LDH/h-BN nanocomposites for removal of two different organic contaminants: Simultaneous visible light photodegradation of Amaranth and Diazepam

Abstract

In the present study, a novel heterostructure nanocomposite consisting of hexagonal boron nitride (h-BN) and ZnTi layered double hydroxide was synthesized to remove two organic pollutants simultaneously from the aqueous solution under visible light irradiation at room temperature. ZnTi LDH/h-BN represents a cost-effective reusable material that showed both adsorption and substantial photocatalytic performance in the degradation of amaranth (AM) azo dye and diazepam (DZP) as organic contaminants of water. Various analyses were performed to assess the morphology, characteristic features, and synthesis accuracy of the as-prepared materials that proved the proper formation of the nanocomposite. Additionally, an acceptable reduction was observed in the bandgap of the nanocomposite in comparison with the bandgap of ZnTi LDH. Furthermore, the effect of various parameters, including pH of the solution, contaminant concentration, and catalyst dosage, were studied on the adsorption and photocatalytic activity to find out optimum conditions during the process. Results revealed that the synthesized catalysts had performed exceptionally well in adsorbing and degrading considered pollutants even in removing both from the same solution. The layered structure of the h-BN played a crucial role in providing an available surface area needed for adsorption and better dispersion of the photocatalyst particles, and at the same time, ZnTi LDH reduced AM and DZP by its photocatalytic activity. In the optimal conditions, the simultaneous removal efficiency of the molecule of AM and DZP was measured to be more than 99% and 95%, respectively.