Based on titanium dioxide(TiO2),Si/TiO2 and Ag@Si/TiO2 composites were prepared by incorporation of nano-silicon (Si) and silver (Ag) particles by aqueous phase coprecipitation method.X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-Visible spectrum,electrochemical impedance spectroscopy(EIS) and photoluminescence spectroscopy(PL) etc.were used to characterize the crystal structure,morphology,optical properties,impedance characteristics and electron hole recombination rate of samples,to find out the effect of the doping amount of elemental composition of Si on the photocatalytic degradation of Rhodamine dye (RhB) and methylene blue (MB) by visible light.Results shown that the visible light absorption spectrum of the composite system containing Si was obviously red-shifted,and the absorption peak appeared in the long wavelength range.When the Si doping amount was 1wt%,the composite catalytic material had the strongest light absorption intensity and the fastest catalytic efficiency.Compared with pure TiO2 particles,the photocatalytic performance of Ag@Si/TiO2 was obviously improved.Under the condition of visible light excitation and degradation for 3.5h,the degradation rate of RhB by Ag@Si/TiO2 was 99%,and under 2.5h conditions,compared with TiO2,the degradation rate reached 14%.On the one hand incorporating Si and Ag into TiO2 nanoparticles,Ag@Si provided more photogenerated electron-hole pairs.On the other hand,Ag acted as an electron acceptor,carrier mobility was improved,and TiO2 semiconductor photogenerated electrons and holes recombination were suppressed,enhanced the degradation efficiency of RhB and MB.
Guo Jun, Yu Chenlu, Zhao Chen, Zhang Zhejuan, Sun Zhuo, Piao Xianqing, Wang Jianqiao
. Influence of nano-silica-silver composite particle on TiO2 visible light photocatalytic activity[J]. New Chemical Materials, 2020
, 48(11)
: 203
-208
.
DOI: 10.19817/j.cnki.issn 1006-3536.2020.11.045
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