Reseach On Bio-Inspired Synthesis Of Iron Oxide Nanoparticles And Their Electrocatalytic Properties

In nature,macro molecules are often used by organisms to direct the formation of bio minerals that are mesocrystals with fanastic morphology and good performance.Inspired by biomineralization,macro molecules are used as growth modifiers to prepare various functional materials with hierarchical structures.Recently,amount of inorganic materials with controlled morphologies were prepared by using soluble and insoluble additives as modifiers.With the advance of synthetic technology,ultrathin inorganic nanomaterial are found to be analogous to supermolecules or supermolecule aggregates.However,using inorganic ultrathin nanowires as growth modifiers to synthesize functional material with good performance remains a problem.Based on the above illustration,this dissertation mainly demonstrate that using xonotlite nano wires(XNWs)to prepare hematite-based nanoparticles whose electrocatalytic activities for watering splitting and CO2 reduction are researched.The main results of this dissertation can be summarized as follows:1.A systhesis system that using XNWs as modifiers to synthesize metal oxide nanomaterials have been established successfully,and hematite particles have been obtained successfully.Our results show that the concentration of XNWs can determine the morphology of the final products and the concentation of the Fe(?)ions can determine the size of the products.Moreover,the formation mechanism of hematite are studied in detail.Noticably,the activity of the obtained hematite for electrocatalysizing oxygen evolution reaction(OER)is good.Hematite particles with a diameter of?100 nm catalyst can afford a current density of 10 mA/cm2 at a overpotential of?0.37 V and a small Tafel slope of 65 mV/decade and show good stability in base electrolyte.2.Using XNWs as growth modifiers to synthesize hematite-based hybrid materials is further researched and Fe2O3/SnO2 hybrid nanoparticles are prepared successfully.We demonstrate a complex process induced by xonotlite nanowires for the formation of Fe2O3/SnO2 hybrid particles by conduct a series of time-depandent experiments.Furthermore,The Fe2O3/SnO2 hybrid particles exhibit excellent performance of electrochemical reduction CO2 to methanol.At an optimal initial molar ratio of Fe(?)ions to Sn(?)ions of 82,the catalyst exhibited a high methanol Faradaic efficiency.Based on the above results,the structure-activity relationship between the Fe2O3/SnO2 interfaces and the activity of electrochemical reduction CO2 have been established and interface related electrocatalytic mechanism have been proposed.