Controllable Synthesis And Photoelectric Property Of The Tungsten Oxide Nanomaterials

In recent years, one-dimensional nanostructure tungsten oxides have attracted widelyattentions due to their unique crystal structure and excellent performance on optical,electrical fields. This dissertation firstly introduces several synthesis methods ofone-dimensional nanomaterial and then studies the controllable vapor deposition methodfor growing tungsten oxide nanomaterial. The properties of as-synthesized tungsten oxidenanomaterial were also investigated for the applications in field emission, supercapacitorand photoelectrochemical. Main work and findings of the dissertation are listed as follows:1. One-dimensional tungsten oxide nanowires were synthesized by vapor deposition.By comparing the morphology of the final sample synthesis by different growthconditions like temperatures, substrates and evaporation time. I determine how to controlthe synthesis conditions and parameters so that we can obtain the one-dimensionaltungsten oxide of uniformity, well orientation, well crystalline, morphology controllable.2. WO_3-x/C core-shell nanowires were prepared by soaking the tungsten oxidenanowires that grown on the carbon cloth into the glucose solution for12h, then annealingunder anaerobic condition. The WO_3-x/C core-shell nanowire exhibited high stability andconductivity as anode of the supercapacitor, and the charging voltage can achieve-1.2V.In addition, such WO_3-x/C core-shell nanostructure can also be used as flexible coldcathode, The carbon coating is beneficial for field emission and can reduced the thresholdfield （from8.83MV/m to6.89MV/m） and increased the field enhancement factor （from1493to1883）.3. After depositing Au nanoparticle film and amorphous MnO₂film onto WO_3-xnanowire with the methods of sputtering and anodizing in succession. We can obtain theWO_3-x/Au/MnO₂core-shell nanowire array on carbon cloth. And the WO_3-x/Au/MnO₂core-shell nanowire can be used as the electrode materials of supercapacitor. Besides, thiskind of electrode material is easily assembled to an all-solid-flexible supercapacitor andLED can be powered with two devices in series.4. By regulating different conditions and parameters in thermal evaporation, we cansynthesize3D network structure WO₃nanomaterial on carbon paper substrate, which its band gap is2.36eV. As a result, it has light-catalyzed reaction on the irradiation of visiblelight. The degradation of RB solution by its catalytic experiment shows that, under theirradiation of visible light,60%of RB can be catalyzed and degraded in4hours, after11hours only about10%RB left. Besides, we synthesis a branched structure WO₃grown onthe FTO conductive glass by secondary growth, it can be applied to photo water splitting,the highest photocurrent density of which can reach2.0mA/cm2（bias of1.5V）, while thehighest incident photon-to-electron conversion efficiency （IPCE） can reach60%or more（λ <400nm） and has a very high light stability and corrosion resistance as well.