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) NiCo _2 O _4 / rGO hybrid nanocomposite was prepared by a facile hydrothermal technique and employed for organic dye adsorption from wastewater. The synthesized NiCo _2 O _4 /rGO hybrid nanocomposite was studied using FTIR, XRD, SEM, TEM, BET, Raman spectroscopy, and UV–visible. The physical characterizations prove the deposition of NiCo _2 O _4 particles on the rGO surface. The transmission electron microscope image demonstrated that the NiCo _2 O _4 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 m ^2 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 BH _4 ^− ions was explained in detail. The electrostatic interaction used between the NiCo _2 O _4 /rGO hybrid composite and Congo red increased the adsorption ion effectiveness of the dye sample.

Keywords

• congo red
• NiCo2O4/rGO hybrid composite
• x-ray diffraction
• FTIR
• TEM