Congo red dye reduction mediated by the electron (e−) transfer route of BH4 − ions using synthesized NiCo2O4/rGO hybrid nanosheets

Abstract

The treatment of toxic organic pollutants is extremely important for the conservation of clean air, soil, and water. In this study, (reduced graphene oxide) NiCo2O4/ rGO hybrid nanocomposite was prepared by a facile hydrothermal technique and employed for organic dye adsorption from wastewater. The synthesized NiCo2O4/rGO hybrid nanocomposite was studied using FTIR, XRD, SEM, TEM, BET, Raman spectroscopy, and UV–visible. The physical characterizations prove the deposition of NiCo2O4 particles on the rGO surface. The transmission electron microscope image demonstrated that the NiCo2O4 particles with an average size of ∼46 nm was dispersed on the rGO surface. The obtained nanoparticles show a higher specific surface area of 56.4 m2 g−1. Adsorption dynamics as investigated by time and concentration variation show that the adsorption data follows pseudosecond order kinetics and the Langmuir isotherm model, with a maximum adsorption capacity of 106.2 mg g−1, indicating homogeneous physiochemical adsorption of CR dye on the adsorbent surface. Besides, the catalytic effectiveness of synthesized nanocomposite towards Congo red (CR) dye reduction mediated by the electron (e−) transfer route of BH4 − ions was explained in detail. The electrostatic interaction used between the NiCo2O4/rGO hybrid composite and Congo red increased the adsorption ion effectiveness of the dye sample.