Preparation Of Nano-semiconductor Materials By Microwave Solvothermal Method And Theirs Photocatalytic Performance

Nanocomposites have attracted extensive attention due to simple preparation methods,large specific surface area,bigger carrying capacity and controllable morphology.Consequently,nanocomposites are widely used as catalysts,catalyst carriers,dielectric materials sensors,etc.Compared with the traditional hydrothermal method,the microwave solvothermal method has great potential in the preparation of nanocomposites materials due to its short preparation time,low energy comsumption and good dispersion of as-obtained samples.A series of TiO2/ZrO2 composites with various molar ratios of ZrO2:TiO2 were synthesized by a facile and mild microwave hydrothermal method with carboxymethyl chitosan(CMCS)as templates.The as-obtained products were characterized with wide-angle powder X-ray diffraction(XRD),scanning electron microscopy(SEM).transmission electron microscope(TEM),Fourier transform infrared spectroscopy(FTIR),UV-vis diffuse reflectance spectrophotometry(UV-vis-DRS),N2 adsorption-desorption isotherms(BET),and X-ray photoelectron spectrometer(XPS).The TiO2/ZrO2 composites with heterogeneous structure consisted of particles which showed a better regularity and uniform with about 800 nm in diameter,and showed a larger specific surface area and smaller energy band gap than pure ZrO2.Comparative experiments including varying the pH of the solution and the content of titania demonstrated that the 5%TiO2/ZrO2 composites(nTi:nZr=5:100)at pH=10.3 possessed the best photocatalytic property.Moreover,the possible reasons for these phenomena were clarified.Cyclic experiments proved that the resulting TiO2/ZrO2 composites as photocatalyst could be reused efficiently.Meanwhile,a possible mechanism of photocatalysis was proposed.Microwave solvothermal method was used to synthesize Zr4+substituted Ti-based MOFs with different content of Zr with butyl titanate as titanium source,butyl zirconate as zirconium source and terephthalic acid(BDC)as ligand.The microstructure and properties were tested by TEM,XPS,BET,UV-vis DRS,XRD,SEM,respectively.The degradation efficiency of Rh B over samples as photocatalysts was obtained under UV radiation.Comparative experiments including varying the pH of the solution and the content of zirconate demonstrated that the T/Z-M-3(nTi:nZr=10.73:100)at pH=10.7 possessed the best photocatalytic property.Meanwhile,a possible mechanism of photocatalysis was proposed.