Hydrothermal Synthesis And Catalytic,Electrochemicmal Performances Of Dual Phase TiO₂ And Hematite Fe₂O₃ Nanostructures

The research progress of TiO2 photocatalysis catalysts and a-Fe2O3 catalysts were reviewed based on the mechanism of photocatalytic reaction and CO2 hydrogenation reaction.Application of a-Fe2O3 as anode material for lithium ion battery was reviewed based on the structure of lithium ion battery.Controlled synthesis of dual phase TiO2 and hematite a-Fe2O3 nanostructures was realized by a hydrothermal method.The application of dual phase TiO2 on photocatalytic hydrogen production and the application of a-Fe2O3 on CO2 hydrogenation reaction were disscussed based on experimental results.Further more,the electrochemical performance of ?-Fe2O3 as anode material for lithium ion battery was carefully investigated-The mian results are summarized as following:(1)Dual phase TiO2 nanoparticles were hydrothermal synthesized by using freshly prepared layered K2Ti8O17 nanofibers as the Ti source and self-assembled mesoporous TiO2 nanofiber structures were obtained when PVA was introduced into the hydrothermal reaction system.Because of the mixed crystal effect,the as-prepared dual phase TiO2 exhibits excellent photocatalytic performance for hydrogen production and its hydrogen production efficiency reaches 4.70mmol/(g h)which is higher than that of P25 TiO2.(2)Spindle-like,drum-like ?-Fe2O3 particles and ?-Fe2O3 microdisks were hydrothermal synthesized in a mixed solvent of ethylene glycol and water.The drum-like ?-Fe2O3 particles and ?-Fe2O3 microdisks were mainly composed of(110)exposing plane.Because of the high Fe3+ density on(110)plane,the drum-like ?-Fe2O3 particles exhibit higher CO2 hydrogenation catalytic performance and the CO2 conversion rate is 12.04%.By adjusting the amount of Fe(NO3)3 · 9H2O introduced into the hydrothermal reaction,the diameter of the ?-Fe2O3 disks was controlled from 1000nm to 100nm,and its thickness was controlled from 300nm to 50nm.As the decrease of its particle size,the coercive field of the ?-Fe2O3 disks becomes smaller and the oriented aggregation along the axial were enhanced.With better dispersibility and smaller grain size,?-Fe2O3 nanodisks with a thickness of 100nm showed better catalytic performance and the CO2 conversion rate reaches 13.57%.(3)The as-prepared ?-Fe2O3 particles showed characteristic electrochemical performance of conversion type anode materials when assembled into a button half battery.By introducing P123 into the hydrothermal system,the dispersibility of the a-Fe2O3 nanodisks was promoted by the the adsorption of P123 on the crystal surface and the remaining P123 would create a carbon layer on the surface of ?-Fe2O3 nanodisks after heat treatment.The carbon-coating ?-Fe2O3 nanodisks with P123 show better electrochemical property as the anode material for lithium ion battery and its initial discharge capacity reaches 1176 mAh/g which is much higher than that of carbon-coating ?-Fe2O3 nanodisks with sucrose.