The study of a novel cobalt-implanted pyridylporphyrin/graphene oxide nanohybrid for enhanced photocatalytic hydrogen evolution and its electron transfer mechanism.

A metallic cobalt nanoparticle-implanted 5,15-diphenyl-10,20-di(4-pyridyl) porphyrin (DPyP)/graphene oxide (GO) nanohybrid (GO-Co-DPyP) was facilely fabricated. By means of XPS, XRD, Raman spectroscopy and UV-vis spectroscopy, it was demonstrated that on implanting metallic cobalt nanoparticles (Co NPs) in the GO, stronger interaction between GO and DPyP can be achieved, which enlarged the included angle between DPyP and GO. The nanohybrid was benifical for light absorption and photo-induced electron transfer. Furthermore, photocatalytic activity for hydrogen evolution over the nanohybrid was investigated. We found that higher activity over the GO-Co-DPyP nanohybrid was obtained, which was about two times higher than that of Co2+ implanted in the GO (GO-Co2+-DPyP). Combined with the results of fluorescence spectra and photoelectronic spectra, the electron transfer mechanism for hydrogen evolution was clarified. This study will provide some theoretical and experimental basis for the assembly and photocatalytic performance of GO-based composites by interfacial modification.