Magnetically separable Ni/g-C3N4 nanocomposites for enhanced visible-light photocatalytic degradation of methylene blue and ciprofloxacin

Abstract

To develop a highly efficient and easily recyclable photocatalysts, graphitic carbon nitride (g-C3N4) nanosheets were hydrothermal synthesized firstly and then magnetic Ni nanoparticles were anchored on g-C3N4 nanosheets with solvothermal method. The morphology, microstructures, magnetic response and photocatalytic activity of all samples were characterized with XRD, TEM, VSM, N2 adsorption–desorption isotherms and spectrophotometer. All results indicate that Ni nanoparticles anchor on the surface of g-C3N4 nanosheets to form Ni/g-C3N4 nanocomposites. The g-C3N4 nanosheets present the higher photocatalytic activity than pristine g-C3N4 powders. The photocatalytic activities to MB and CIP of Ni/g-C3N4 nanocomposites are much higher than those of g-C3N4 nanosheets. The interface between Ni and g-C3N4 forms the metal-semiconductor heterojunctions, which plays a dominated role on electron transition near interface. The photogenerated electrons near interface prefer to transfer from g-C3N4 nanosheets to Ni nanoparticles, resulting in the separation of photogenerated electron-hole pairs. Furthermore, Ni/g-C3N4 nanocomposites could be easily separated from the solution after photocatalysis.