Preparation Of Two Dimensional Nanomaterials?WO₃,ZrMo₂O₈? Nanosheets And Their Application

Owing to their extremely high percentage of exposed surfaces,exotic electronic properties,high chemical activity and unusual physical and chemical properties,two-dimensional nanomaterials can be widely used in a wide range of fields including optoelectronic,catalysis,sensors,biology,energy conversion.However,practical preparation of two-dimensional nanomaterials still faces the great challenge in acquisition of high quality,high yield and excellent proformance.So far the main fabrication methods of two-dimensional nanomaterial include liquid-phase exfoliation,ion intercalation,micromechanical cleavage and hydrothermal synthesis.Among these approaches,the liquid-phase exfoliation method is limited by the low exfoliation degree and efficiency.The sample synthesized by micromechanical cleavage has uncontrollable sizes and poor repeatability.Too complicated procedure makes ion intercalation unsuitable for large-scale synthesis.Solvothermal synthesis,as a kind of hydrothermal method,is of particular interest,due to simple experimental equipment,mild reaction conditions,simple operation,high product yield and controllable morphology.In our work,we chose the mixture of ethanol and water as solvent,and fabricated two-dimensional nanosheets through simple solvothermal methods.Defect was introduced to further improve the performance of nanosheets.Moreover,we investigated the properties of as-prepared two-dimensional layered nanosheets in electrochromism and photoeletrochemical performance.The main contents are shown as follows.(1)Defect Engineering of Two-dimensional WO3 Nanosheets for Enhanced Electrochromism and Photoeletrochemical PerformanceUsing Pluronic P123 as surfactant,tungsten chloride as the precursor,the mixture of ethanol and water as the solvent,two-dimensional ultrathin tungsten trioxide nanosheets were obtained through facile solvothermal methods.The products have a complete structure and ultrathin thickness.The annealing treatment was carried out to improve the crystallinity.Hydrogen processing was used to introduce abundant oxygen vacancies.Tungsten oxide nanosheets with abundant surface oxygen vacancies show excellent electrochromism and photoeletrochemical performance,which provides a great opportunity for tungsten oxide to be widly used in optoelectronic and catalysis fields.(2)The Preparation of Zr Mo2O8 Nanosheets for Photoeletrochemical PerformanceTwo-dimensional molybdenum trioxide nanosheets were successfully fabricated by liquid-phase exfoliation,which was considered as one of precursors.Using the mixture of ethanol and water as the solvent,two-dimensional zirconium molybdate nanosheets were obtained through simple solvothermal methods.The morphology of zirconium molybdate nanosheets can be controlled by regulating the temperature of the solvothermal reaction.Owing to high specific surface area and high chemical activity,zirconium molybdate nanosheets show the admirable photoeletrochemical performance,indicating potential application in photocatalysis fields.