Synthesis, Modification And Corrosion Resistance Of Cadmium Sulfide Photocatalyst

In this paper,CdS nanoparticles(CdS NPs),PPy-coated CdS nanocomposites(PPy/CdS NCs)and SiO2@void@CdS were synthesized by solvent-thermal precipitation method,in situ deposition oxidative polymerization and sol-gel method respectively.The characterization methods Field-emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FTIR),X-ray powder diffraction analyses(XRD),UV-visible absorption spectroscopy(UV-Vis DRS),Varian VISTA-MPX inductively coupled plasma optical emission spectrometer(ICP-OES)and Brunner-Emmet-Teller(BET)were used to reveal the morphologies,crystal structure,visible light absorption,stability and adsorption performance.We also discussed the reaction mechanism and photocatalytic performance under visibe light irradiation.A series of PPy/CdS NCs with different Py doping amounts were used to degradation of methylene blue(MB)/rhodamine B(RhB)and the removal efficiency increased first and then decreased.The optimal ratio of CdS/Py was 3/20(wt).Removal efficiency of PPy/CdS NCs for MB and RhB is up to 99.93%and 99.34%respectively,which was higher than CdS.The results reveal that the band gap of PPy/CdS NCs was reduced to 1.25 eV,which expand the absorption region of CdS.On the one hand.PPy can improve the photocatalytic activity as a photosensitizer.On the other hand.PPy can improve the photostability of CdS as a protective layer.Moreover.PPy/CdS-5 maintain the degradation efficiency to be 89.48%after 10 cycles,showing an excellent reusability.The removal efficiency of Cr6+ from K2Cr2O7 solution was up to 35.1%when pH=2 and reaction time was 3 h.A series of SiO2@void@CdS with different PPy doping layers were prepared and when the number is 5.the specific surface area of SiO2@void@CdS-5 was up to 402.106 m2/g,which exhibits an excellent photocatalytic and adsorption property.The final efficiency of MB under dark conditions and visible-light irradiation confirm that the photocatalytic degradation is the combination of adsorption and photocatalysis.On the one hand,SiO2 shell can protect CdS from photocorrosion.On the other hand.it can reduce the damage to the substrate.It is a new kind of high efficiency photocatalyst which combines photocatalysis and adsorption,leading to its strong applied value in many areas.