Fabrication and characterization of CdS nanowires templated in tobacco mosaic virus with improved photocatalytic ability.

Abstract

Using a virus as a template to synthesize nanomaterial is a simple, green, and controllable method to acquire unique structure nanoparticles. In this study, CdS nanowires were synthesized using the tobacco mosaic virus (TMV) as a template and for deposition in the inner center channel of TMV. TMV/CdS was successfully characterized, with the results showing a diameter of 4.0 nm, a cubic-phase composition, and strong fluorescence emission peaks, with an absorption edge of 566 nm and bandgap energy of 2.28 eV. The bandgap energy is narrower than that of template-free CdS. Furthermore, TMV/CdS exhibited an increased transient photocurrent, which was attributed to the effective separation of electron-hole pairs. The photoactivities of TMV/CdS and template-free CdS were tested; the results showed that the TMV/CdS had a better performance in methylene blue (MB) photodegradation, indicating that the photoactivity of TMV/CdS was higher than that of the template-free CdS. Further research on TMV/CdS regarding the photocatalytic mechanism showed that O2•- and •OH were the major species involved in photocatalysis, rather than holes (h+). Therefore, TMV/CdS might have applications as a novel visible-light-responsive photocatalyst. KEY POINTS: • CdS nanowires were firstly synthesized in the inner center channel of TMV • TMV/CdS presented higher photocatalytic efficiency compared with template-free CdS • The O2•- and •OH were responsible for the photocatalytic reaction of TMV/CdS.