Synthesis of high performance Ni3C-Ni decorated thermally expanded reduced graphene oxide (TErGO/Ni3C-Ni) nanocomposite: A stable catalyst for reduction of Cr(VI) and organic dyes

Abstract

A high performance thermally expanded reduced graphene oxide (TErGO) nanocomposite decorated with Ni₃C-Ni nanoparticles (TErGO/Ni₃C-Ni) has been successfully synthesized by using a facile and eco-friendly approach. The morphology, textural features, surface composition and stability of TErGO/Ni₃C-Ni nanocomposite are investigated by various physicochemical characterizations which revealed the uniform dispersion of crystalline metal nanoparticles inside TErGO matrix. The composite has been exhibited a large surface area and pore volume of 121 m² g^-1 and 0.791 cm³ g^-1, respectively. The TErGO/Ni₃C-Ni exhibited remarkable catalytic performance surpassing most metal-based catalysts with various kind of support matrices reported in recent literature. The reduction of Cr(Ⅵ) to Cr(Ⅲ) was achieved within 1 min with an excellent rate constant of 2.74 min^-1 and phenomenally higher specific removal rate (SRR) of 0.29 mg Cr(VI) min^-1. mg^-1 of TErGO/Ni₃C-Ni. While it also proved an excellent reducing catalyst for organic dyes via NaBH₄ with full reduction achieved within 30 s. Moreover, as prepared nanocatalyst possesses excellent stability and recyclability with easy magnetic separation.

Keywords: Catalyst; Cr(VI) reduction; Organic dyes; Thermally expanded reduced graphene oxide.