Controllable Construction Of Red Phosphorus/cobalt Phosphide Heterojunction And Its Efficient Photocatalytic Water Splitting Performanc

Solar-driven photocatalytic water splitting for hydrogen production is considered to be one of the most promising technologies to solve the problems of deepening environmental pollution and energy crisis.Red phosphorus（RP）has a narrow bandgap of less than 2.0 eV,can split water to obtain hydrogen under visible light,and the nontoxic,stable,and inexpensive properties of RP make it the most promising photocatalytic hydrogen production catalyst.However,due to the high recombination efficiency of photogenerated carriers inside RP and slow surface reaction kinetics,its practical application is severely limited.Therefore,in this paper,RP/transition metal phosphide heterojunctions with different morphologies were constructed by compounding non-metal RP and transition metal phosphide to enhance charge separation and surface reaction.Photolysis of water for hydrogen evolution and reaction mechanism of water were studied.The main contents of the research are as follows:1.Cobalt phosphide（CoP₂）-modified RP heterostructures were prepared by an in-situ phosphating strategy using phosphorus vapor generated at high temperature from commercial RP using silica microspheres as a template.By adjusting the content of CoP₂ in the heterostructure,the hydrogen evolution rate of the optimized hybrid material under visible light reaches 11.79μmol·h^-1,which is 3.5 times that of Pt as a cocatalyst.Experiments show that the tight interfacial interaction between CoP₂ and RP enhances visible light absorption and accelerates photoinduced electron-hole separation.In addition,CoP₂,as a non-precious metal cocatalyst,can promote the surface hydrogen evolution reaction and synergistically benefit the photocatalytic hydrogen production activity.2.The RP/CoP₂/SiO₂ prepared by in-situ phosphating was etched with ammonium bifluoride solution,and then the SiO₂ microspheres were removed to prepare rod-shaped RP/CoP₂ composites.After further analysis,one end of the rod-like structure is a CoP₂ cocatalyst.The optimized rod-shaped photocatalyst increases the specific surface area and active sites,and the one-dimensional rod-shaped red phosphorus promotes the charge transport performance,which further improves the hydrogen evolution rate of the composite under visible light,reaching 13.10μmol·h^-1,which is Using Pt as a cocatalyst is 4 times higher,and the stability can be greatly improved at the same time.