Study Of G-C₃N₄-doped/driven Nanocomposites As Hydrogen Evolution Reaction Electrocatalyst

With the shortage of energy and environmental crisis,hydrogen energy as an ideal energy has received great attention.Among them,electrolytic water has many advantages such as simple condition and wide range of application,which is expected to be one of the main ways to produce hydrogen in the future.Until now,platinum-based noble metals?Pt,Pd,Ru?have the best electrocatalytic activity,but their commercial applications are limited by their reserves and prices.Graphite-type carbon nitride?g-C₃N₄?is a new type of synthetic material with stable structure,easy preparation and good conductivity.Recently,it has been widely studied in the fields of light,electricity,catalysis and so on.The theoretical study shows that carbon self-doping can form a large delocalized?bond,which leads to the band structure change of g-C₃N₄,the enhancement of electrical conductivity,the increase of specific surface area and the enhancement of redox activity.On the basis of previous theoretical research,it is proposed to design and synthesize non-metallic B and non precious metal doped carbon nitride to obtain electrocatalytic materials with high active sites and good conductivity.The main contents are as follows:1.Using boric acid as the boron source and the“doping”strategy to synthesize boron element-doped carbon nitride?B-g-C₃N₄?,boron substituted mesh grid structure in the C atoms to form a?-bond bonded flat layered structure.The effect of doping amount on structure and morphology was studied in detail.The activity and stability of the composite towards electrocatalytic p-nitrophenol?p-NP?were investigated by cyclic voltammetry.The electrocatalytic hydrogen evolution activity and its stability of the catalytic materials were investigated by electrocatalytic hydrogen evolution experiments.2.The low cost dicyandiamide was used as the pyrolysis precursor of g-C₃N₄,and the CoCl₂·6H₂O was mixed with dicyandiamide as non-precious metal precursor and then under programmed calcination at high temperature.N-doped,defects-rich carbon nanotubes?CNTs?encapsulated with cobalt nanoparticles were formed in situ.The effects of synthesis temperature,kinds of metal?Fe,Co,Ni?and mass ratio of precursor on the structure and properties of the products were discussed.The electrocatalytic hydrogen evolution activity and stability of composites were investigated under pH-universial conditions,which exhibit Pt-like activity and stability.The study provide data support for industrial application of materials.3.In order to further improve the electron donor-acceptor environment in the catalytic system and increase the density of active sites,carbon nanotubes?CNTs?coated polymetallic nanomaterials were developed.Anhydrous ferric chloride was added as the second metal element precursor in the preparation of transition metal-doped graphite phase carbon nitride and the influence of different ratio of iron and cobalt on the morphology and electrocatalytic performance of the sample was investigated.The low-cost,highly active and stable electrocatalytic hydrogen evolution materials were obtained.