Titanate Nanotubes Integrated with Cuprous Oxide Exhibit Better Photocatalytic Activities

What is the reason behind constructing nanocomposite for the photocatalytic oxidation desulfurization?

With current hydrodesulfurization (HDS) technology it is hard to remove thiols and refractory thiophenic compounds to a minimum in fuels. Furthermore, the HDS technique requires severe operation conditions, along with other disadvantages in deep desulfurization. Hence, significant focus has been paid to non-HDS methods such as biodesulfurization, adsorption, photocatalytic oxidation and so on. Of all these, the photocatalytic oxidation desulfurization is the most ideal “green chemistry” technique for performing deep desulfurization with mild operating conditions. A few Researchers have described nanocomposite as an effective photocatalytic functional material than just the host, for example, Nb₆O₁₇-Fe₂O₃, Cu₂O-TiO₂ nanotube arrays, etc.

The high photocatalytic activity of the titanate nanotubes under UV light irradiation has made it a material of choice. Yet, titanates have a comparatively wide band gap and are used only under UV light, thereby restricting their photocatalytic activity. Furthermore, while using only Cu₂O as a photocatalyst, the holes and electrons excited by light are not effectively transferred and can readily recombine with each other. A few research teams adapted a novel idea and composited Cu₂O nanoparticles by using titanate nanotubes, leading to wider absorbance and intense visible spectral response. This approach offers an innovative way to minimize the band gap energy and extend the dissociation between photo-generated electron-hole pairs, which resulted in better photocatalytic activities for photodegradation of organic pollutants more thoroughly.

The most remarkable feature of this research is that when Cu₂O nanoparticles were composted by using H₂Ti₃O₇ nanotubes as an effective photocatalyst used for desulfurization, the construction as well as desulfurization application of these functional materials was hardly described in earlier studies. Initially, the photocatalytic oxidation desulfurization is taken to be the best suited “green chemistry” technique for deep desulfurization with moderate operating conditions when compared to the prevalent HDS techniques. Then, the trititanate nanotubes are constructed. Earlier studies have showed that certain layered titanates were found to be good photocatalysts, and the corresponding nanotubes and nanosheets even demonstrated considerably greater photocatalytic activities when compared to the original layered compound. Moreover, the Cu₂O-H₂Ti₃O₇ nanocomposite has been synthesized such that the mesoporous nanoscroll composites have evidently greater photocatalytic activities when compared to host layered materials or guest oxide nanoparticles taken alone. The research suggests that apart from reducing the bandgap, the layered materials doped with guest nanoparticles can also prevent the photoinduced electron-hole pairs from getting recombined. Hence, in this study, Cu₂O nanoparticles integrated H₂Ti₃O₇ nanotubes have been used by means of a facile hydrothermal technique, demonstrating that nanocomposite has exceptional photocatalytic performance owing to its wider absorbance and stronger visible spectral response. This study can become the basis for developing innovative energy resources (solar energy) and oxidizing organic pollutants for protecting the environment.