Enhanced charge separation in g-C₃N₄@MnFe₂O₄@rGO ternary heterostructure nanocomposite for visible light photocatalytic degradation of methylene blue dye and hydrogen production

In this study, graphitic carbon nitride (g-C₃N₄) reinforced MnFe₂O₄@ reduced graphene oxide (rGO) nanocomposite (g-C 3 N 4 @MnFe 2 O 4 @rGO) was prepared using a hydrothermal method followed by thermal treatment. The synthesized nanomaterial was used as a new visible-light photocatalyst for the degradation of methylene blue (MB) dye from water. Again, this material was also used to create clean hydrogen (H 2 ) energy using a photochemical method. MnFe₂O₄ nanoparticles in the shape of cubes are added to create a linked heterojunction system. 2D graphene oxide (GO) nanosheet was added with g-C 3 N 4 and MnFe 2 O 4 to improve electrical conductivity, surface area, and interfacial electron transfer. After calcination, GO was converted into reduced graphene oxide (rGO) through thermal reduction. The crystallinity, functional groups, bonding, morphological properties, optical properties, and electrical properties were determined using XRD, FTIR, Raman, FESEM, HRTEM, UV-DRS, and Electrochemical impedance spectroscopy. The formation of cubic spinel nanostructure on g-C 3 N 4 and rGO surfaces was confirmed by XRD and FESEM analysis. The band gap of the composite material was found to be 2.57 eV. An 98% dye degradation was obtained within 120 min, and the H 2 production rate of the optimized nanocomposite was 1050µmolesg −1 , which is greater than that of g-C₃N₄ and g-C 3 N 4 @MnFe 2 O 4 .Cyclic degradation studies confirm the enhanced performance and cyclic stability of the catalytic material. This increased effectiveness of the nanocomposite can be attributed to heterojunction formation, which allows for an efficient separation of photogenerated electron-hole pairs. The MnFe 2 O 4 nanocubes and plasmonic rGO promote the synergistic enhancement of the visible light absorption, effective charge separation, and number of surface-active sites on g-C₃N₄.