ZnSe-rGO nanocomposites as photocatalysts for purification of textile dye contaminated water: A green approach to use wastewater for maize cultivation

Disputes about the probable availability of safe water and the efficacy of processed wastewater are key issues that necessitate a suitable solution to enhance the quality of clean water. The current research emphasizes the synthesis of ZnSe-reduced graphene oxide nanocomposites (ZnSe:rGO) with different weight ratios of rGO (represented as X = 0.6, 1 and 1.6 g)via one-step hydrothermal method. The photocatalytic performance for the degradation of methyl violet (MV) dye was investigated under visible light irradiation by varying the reaction parameters. The crystal structure, elemental composition, surface functionality and morphology of the synthesized ZnSe-XrGO nanocomposites were estimated by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. UV–visible spectroscopy was used to investigate the optical properties. The highest efficiency is obtained for ZnSe-XrGO in 1:1 and it showed pseudo 1st order behavior with rate constant of 0.0167min⁻¹and 94 % photodegradation of MV in just 3 h. Furthermore, hazardous effects of MV were investigated on the germination and growth of Zea mays seeds by giving them aqueous solution of MV (0, 8, 12, 24 and 48 ppm) and the decontaminated water after photodegradation of MV with the synthesized photoactive composite. The results showed profound negative effect on both germination and seedling growth at higher concentration (>12 ppm) of the dye solution. No hazardous effects were observed on both these parameters when it was given the dye degraded water which reflects the practical use of the synthesized catalyst for water remediation. The current study fulfills the goal of designing an efficient visible-light active nano-photocatalyst and its direct applicability on life sciences for water purification.