Novel Simarouba glauca extract mediated biocompatible reduction of graphene oxide for robust scavenging of dyes and promising electrochemical applications

Abstract

Dyes and pharmaceutical products are major environmental contaminants in the effluent of various industries such as cosmetics, textiles, pharmaceuticals, etc. Moreover, these non-biodegradable pollutants are frequently discharged into the water media without adequate precautions. Because of their intricate aromatic structures, dyes are resistant to natural degradation processes. As a result, various treatment techniques have been developed to remove dyes. Green synthesis is one such environmental technique regarding an alternative perception for the degradation of harmful materials like heavy metals, dyes etc. by exploiting biological samples. Therefore, in the present study dye adsorption and desorption studies of the green synthesised reduced graphene oxide (RGO) were investigated. The study presents an effective green reduction method for the facile synthesis of RGO using novel Simarouba/(Lakshmi Taru) extract through the reflux method at a temperature of 90 °C. As synthesised RGO has been analysed by SEM, XRD, Raman, UV–visible, Photoluminescence, TGA analysis, and FTIR studies. Cyclic voltammetry study exhibited a substantial improvement in current density for the RGO-3 hr sample. The maximum reduction efficiency of RGO accomplished using 100 ml of Simarouba extract was found to be 80% and it exhibits an outstanding capacity for the removal of dye with 94% efficiency. It was reported that Rhodamine B dyes were completely adsorbed within 10 min using 20 mg of RGO. It is investigated that adsorption follows langmuir isotherm model and pseudo-second-order kinetics. The thermodynamic studies specified that the whole adsorption is spontaneous, endothermic and physisorption in nature. The electrostatic interaction between the negatively charged surface of graphene oxide and reduced graphene oxide and positively charged surface of rhodamine B is responsible for the high affinity of adsorption of the graphene oxide and reduced graphene oxide. The proposed study reports the synthesis of highly stable and recyclable green-reduced GO by a cost-effective and eco-friendly technique.