Preparation Of Nitrogen-Doped Carbon Nanofibers And Its Application In Electrocatalytic Hydrogen Evolution

Energy and environmental problems are the two major problems of sustainable development of human.Green energy without pollution to the environment is the pursuit of all the scientists.Hydrogen production from water splitting is a kind of hydrogen production technology with wide application prospect because of its green and high efficiency.At present,the high activity of the water electrolysis catalyst are mainly Pt and other precious metal catalysts,however,its low-abundance and expensive cost seriously hamper its industrial applications.Due to its rich reserves,low cost and other characteristics,nitrogen-doped carbon materials is a promising catalyst for electrolysis of water and scientists have paid much attention on them.In this paper,nitrogen-doped carbon fibers(NCNRs/CNFs)were prepared by electrospinning combined with in-situ polymerization and chemical complexation.Then we prepared the nitrogen-gold nanoparticles co-doped carbon nanofibers(AuNPs@NCNRs/CNFs)using the(NCNRs/CNFs)as supporter.We systematically studied its microstructure and electrocatalytic activity for hydrogen evolution.The main contents are as follows:(1)The NCNRs/CNFs hybrid materials were prepared by electrospinning,in-situ polymerization and high-temperature graphitization,and their structures and properties were characterized by Field Emission Scanning Electron Microscope(FE-SEM),Transmission Electron Microscopy(TEM),X-ray Diffractometer(XRD)and X-ray Photoelectron Spectroscopy Analysis Instrument(XPS).The average diameter of the prepared CNFs was between 160 nm and 200 nm.After in-situ polymerization,aniline was successfully polymerized as polyaniline on the surface of CNFs.NCNRs/CNFs were successfully prepared by a calcination process at high temperature.The results of electrocatalytic hydrogen evolution showed that NCNRs/CNFs hybrid materials exhibited better electrocatalytic activity and stability than those of CNFs.(2)In order to further improve the hydrogen evolution properties of the hybrid materials,AuNPs@NCNRs/CNFs were prepared by co-doping NCNRs/CNFs and a small amount of gold nanoparticles,the results showed that the AuNPs were homogeneous distributed on the surface of NCNRs/CNFs.The results of electrocatalytic hydrogen evolution showed that the initial overpotential of AuNPs@NCNRs/CNFs was about 126 mV and the Tafel slope was about 93 mV dec-1.The results showed that the excellent electrocatalytic activity of hydrogen evolution was mainly due to the strong synergistic effect between AuNPs and NCNRs/CNFs.Due to the introduction of AuNPs,the Gibbs Free Energy(?GH)of the HER process was reduced,which facilitates the rapid hydrogen evolution reaction.