Preparation Of CdS Nanomaterials By Virus-Templated And The Investigation Of Their Photocatalytic Properties

Virus template method,as a new synthesis method of nano-materials,has been developing for 20 years.The synthesis and analysis technology is becoming more and more mature,and it has been paid more and more attention in the field of current research.The metal nanomaterials synthesized by virus template have good stability,dispersion and biocompatibility.They have excellent performances in catalysis,optics,electricity,magnetism and superconductivity and so on.In the synthesis of metal nanomaterials by viral template method,template proteins can provide deposition sites for metal ions and bind to metal ions at fixed sites,and can be selectively controlled to synthesize nanomaterials according to the template structure.At the same time,metal nanoparticles can be effectively prevented from reuniting due to the steric effect of virus template itself.Moreover,template viruses are abundant in nature,easy to be prepared,and come from a wide range of sources which can greatly reduce the cost of preparation.Semiconductor photocatalysis is a kind of technology which can convert light energy into chemical energy under mild conditions for redox reaction.In recent years,it has become one of the most promising technologies in the treatment of environmental pollution,because of its high reaction activity,catalytic efficiency and non-selectivity of catalytic substrates.In this paper,the semiconductor photocatalytic material TMV-CdS is synthesized by virus template method,which has the structural advantage of virus template and the unique properties of nano-sized CdS.The apparent and performance differences between the semiconductor photocatalytic material CdS and template-free synthesis CdS are compared.The TMV-CdS was applied to the degradation of methylene blue,and the photoelectron production of the dye on the growth of microorganisms and the interaction with the dye.Analysis of TMV-CdS by transmission electron microscope,energy spectrum analysis,X-ray diffraction,ultraviolet visible diffuse reflectance spectrum,fluorescence spectrum and etc.The results showed that the CdS prepared by viral template was located in the inner central channel of TMV and was a 4nm nanowires with the component of CdS except protein.The absorption band edge was about 550 nm and the band gap was Eg=2.28 eV.When TMV-CdS is excited by the light of 360 nm,there is a strong fluorescence emission at 530 nm.The photocatalytic degradation rate of methylene blue by TMV-CdS was 92.45%higher than that of 90 min photocatalysis by template-free CdS.It could be degraded into small molecular substance,and it still had good degradation effect in high concentration dye environment.The degradation rate of TMV-CdS was still more than 70%after 4 cycles,which was slightly stronger than that of template-free synthesis of CdS.It was proved that·O₂^- played a major role in the photodegradation of TMV-CdS.Under light condition,it is found that the photoelectron-producing ability of TMV-CdS is much stronger than that of template-free CdS.TMV-CdS could promote the growth of E.coli,the growth rate could reach 9.44%,but the effect of template-free CdS on the growth of E.coli was weaker than that of template-free CdS.The effect of adding p-benzoquinone on the growth of E.coli was weakened,but the addition of ascorbic acid was slightly enhanced,and the growth rate of E.coli was 10.75%and the degradation rate of congo red was 1.29%after adding congo red to E.coli,and the growth rate of E.coli was 10.75%and the degradation rate of Congo red was 1.29%.After adding methylene blue,the growth rate of E.coli was-27.30%that slower than the normal state.And the degradation rate of methylene blue was 28.15%.