Structural feature, morphology and optical properties of g-C3N4 decorated CuO-Fe3O4 nano composite for electrocatalytic and photocatalytic applications

The present work, novel growth of ternary CuO-Fe3O4/g-C3N4 nanocomposites (NCs) with three different ratio (CuO-Fe3O4:g-C3N4 = 90:10; 75:25 and 50:50), binary CuO-Fe3O4 nanocomposite (NC) and its pristine g-C3N4, CuO and Fe3O4 was synthesized and characterized by XRD, SEM with EDX, TEM, Raman, XPS, UV-DRS and PL. The XRD pattern exhibited the diffraction peaks of g-C3N4 (hexagonal) and CuO (monoclinic) and Fe3O4 (FCC) and the CuO-Fe3O4 mixing of monoclinic and cubic phases along with CuO (−111) direction. The TEM analysis shows the dispersion of CuO-Fe3O4 on g-C3N4 sheets in the CuO-Fe3O4/g-C3N4 (50:50) NC. From the XPS spectra, the oxidation states of Cu2p, Fe2p, O1s, C1s, and N1s, as well as their orbital bonding, are analyzed. The bandgap was calculated by photon energy vs ILD and (F(R∞)hv)2 by using UV-DRS spectrum. The catalyst, CuO-Fe3O4/g-C3N4 (50:50)@NF had a low overpotential of 69 mV at the current density of 10 mA cm2, close to the value of 20 % Pt (45 mV). A chronoamperometry test demonstrated that CuO-Fe3O4/g-C3N4 (50:50)@NF works efficiently for more than 30 h at a high current density of 15 mA cm−2 indicating the strong stability of CuO-Fe3O4/g-C3N4 (50:50)@NF. The maximum photocatalytic degradation efficiency against Rhodamine-B was found to be 99.51 % and crystal violet degradation efficiency is 98.02 % by using CuO-Fe3O4/g-C3N4 (50:50).