Optical, electrochemical, electronic environments and anti-corrosion properties of V2NTx MXene reinforced rGO nanocomposites

Abstract

Herein, 2D V₂NT_x MXene/rGO nanocomposites were synthesised by preferential etching Al layer from the V₂AlN MAX precursor utilizing NaF and HCl solution and a reducing agent. With the introduction of rGO, the highest intense peak shifted towards a lower 2θ value, indicating an increase in d-spacing in V₂NT_x MXene/rGO composites. Accordion-like MXene/rGO structure was observed with layer spacing from 0.20 to 2.1 μm in V₂NT_x/rGO nanocomposites. Introducing rGO in V₂NT_x MXene protects the surface from undesirable reactions and oxidation. Due to the quantum confinement effect, the Tauc absorption band gaps ranged from 4.75 to 5.11 eV. The surface area and pore diameter of V₂NT_x MXene were enhanced after the introduction of rGO, which were 172.52 m²/g and 182.82 nm, respectively. However, a significant improvement in the electrochemical measurement of V₂NT_x MXene was observed with rGO introduction with the highest specific capacitance (C_p) of 5.69–126.11 F/g in cyclic voltammetry and 19.22–622.97 F/g in galvanostatic charge-discharge in 1M H₂SO₄. The cyclic stability was maintained at 88.3 % after 10,000 continuous charge and discharge cycles. The Energy and power densities ranged from 2.66 to 864.44 Whkg⁻¹ and 499.59–2499.73 kWkg⁻¹, respectively. The (V₂NT_x)_0.25/rGO_0.75 sample showed a corrosion rate of 1.5 × 10⁻⁸ mm/y, which is 1.46 and 4.46 times less than V₂NT_x MXene and rGO. In addition to providing an abundance of active sites for electric double-layer capacitors and pseudocapacitance, rGO gave V₂NT_x MXene/rGO with increased porosity and an interwoven laminar network, both of which are essential for electrolyte access and charge transmission.