Synthesis and visible-light photocatalytic degradation performance of BaNiO 3 /g-C 3 N 4 heterojunction for aniline blue degradation

Abstract A BaNiO 3 /g-C 3 N 4 heterojunction was synthesized via green synthesis approach using the Peganum harmala leaf extract as reducing agent. A comprehensive characterization of the pristine and nanocomposite photocatalysts was performed using XRD, FTIR, EDX, UV–vis DRS, and PL techniques to investigate their physicochemical properties. The microstructural data revealed the presence of BaNiO 3 and g-C 3 N 4 phases with crystallite sizes ranging from approximately 10 to 60nm crystallite size and FTIR results confirmed the coexistence and interaction of characteristic functional groups associated with BaNiO 3 and g-C 3 N 4 . The UV–vis DRS analysis indicated a reduction of the BaNiO 3 bandgap energy from 3.31 to 2.86eV upon incorporation of g-C 3 N 4 , indicating improved visible-light absorption and optical response of heterojunction. The catalytic activity of developed composite was assessed through the degradation of the Aniline blue (AB) dye under visible light irradiation. The nanocomposite achieved 94% removal of AB dye within 80min, corresponding to a kinetic rate constant of 0.0273min -1 . Its enhanced photocatalytic performance is attributed associated with the formation of an intimate heterojunction between the two components, which can facilitate interfacial charge separation and suppress electron-hole recombination, as indicated by the PL results. Radical trapping experiments further revealed that • OH and • O 2− species play important roles in AB dye degradation.