Multifunctionality of Partially Reduced Graphene Oxide–CrVO 4 Nanocomposite: Electrochemical and Photocatalytic Studies with Theoretical Insight from Density Functional Theory

The CrVO 4 and reduced graphene oxide (rGO)–CrVO 4 composite has been synthesized through solid-state reaction and modified Hummer method and ultrasonication-assisted solid-state reaction method, respectively. The structural, compositional, and morphological features were studied by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The Raman spectroscopy shows the indicative GO, and CrVO 4 peaks, respectively, and the coexistence of these peaks in composite material. The photocatalytic activity of rGO–CrVO 4 composite evaluated by photocatalytic degradation of methylene blue dye under UV-light irradiation shows improved ability for composite as compared to the parent compound CrVO 4 . The rate constant evaluated for rGO–CrVO 4 is 6.7 × 10 –2 min –1 . Electrochemical characterization through cyclic voltammetry, galvanostatic charging and discharging, and impedance analysis was carried out. The rGO–CrVO 4 composite exhibits a higher specific capacitance, 102.66 F/g @ current density of 0.5 mA/cm 2, as compared to the parent CrVO 4, 30.87 F/g @ current density of 0.5 mA/cm 2 . We have also performed extensive density functional theory simulations to qualitatively support our experimental findings by presenting the quantum capacitance and providing the insight from electronic density of states for enhanced capacitance for rGO–CrVO 4 nanocomposite. Presence of additional C 2p states from rGO results enhanced the density of states which is responsible for improved supercapacitance performance of rGO–CrVO 4 compared to bare CrVO 4 . These encouraging results illustrate the exciting potential for-high performance applications for GO composites with multifunctionality for multiple applications.