Bismuth Iron Vanadate/carbon Nanotube Heterostructure Flocs And Photoelectrochemical Decomposition Of Seawater To Produce Hydroge

With the rapid development of modern industry and economy,non-renewable fossil energy sources such as coal and oil are not only difficult to sustain the global energy consumption of 1600 trillion tons of standard coal per year,but also bring serious environmental pollution and ecological damage.Green and safe renewable energy has become an important component of the contemporary energy reform system in China,which is important for optimizing energy structure,improving ecological environment,coping with climate change and promoting sustainable development of modern society.Hydrogen energy has the advantages of high calorific value,zero emission and no pollution,and is an ideal renewable energy source.Among many industrialized hydrogen production technologies,Photoelectrochemical（PEC）has obvious superiority in decomposing water to produce hydrogen,and its high-efficiency semiconductor photoelectrode can convert abundant solar energy into hydrogen energy,avoiding the drive and transmission of electricity.In addition,the earth is short of fresh water resources,with seawater accounting for 97%of the total,and is a natural electrolyte solution.Therefore,PEC seawater decomposition for hydrogen production has become a hot research topic today.Efficient hydrogen production via PEC seawater splitting requires strict demands for light absorption and carrier migration of the anode materials constructed by n-type semiconductors.Among them,Bi VO₄,with a band gap of only 2.4 e V and safe and non-toxic,is a promising semiconductor material for PEC seawater splitting for hydrogen production.However,the photogenerated electron mobility of Bi VO₄ is logy and easy to recombined with hole,resulting in an inhibited PEC efficiency.Aiming at this bottleneck,in this paper,the transition metal Fe doped Bi VO4 nanoparticles were combined with carbon nanotubes（CNTs）to successfully construct flocculent heterogeneous nanostructures,which greatly improved the carrier migration efficiency.The flocculent heterogeneous nanostructures（HNS）of Bi_xFe_1-xVO₄@CNTs,as the photoanode for PEC seawater splitting,show high photocurrent density and long-term stability.In this heterogeneous structure,Fe-doped Bi_xFe_1-xVO₄ nanoparticles have a narrower band gap than Bi VO₄ intrinsic semiconductors,which widens the spectrum range of visible light absorption and improves the utilization efficiency of sunlight.On this basis,CNTs,acting as a fast channel for electrons,inhibited the recombination of photogenerated electrons and holes,thus significantly improving PEC efficiency.Using natural seawater as electrolyte,the photocurrent density reaches 0.1 m A/cm² at 1.5 V（.）with excellent stability,which shows its potential for future application in the"hydrogen economy"and provides a technical reference for future photochemical hydrogen production from seawater.