Influence of post-heat treatment on photocatalytic activity in metal-embedded TiO2 nanofibers

With the increasing concerns for environmental pollution, photocatalysts have been attracting attention due to their environmentally friendly characteristics, low cost, and simple processing. Titanium dioxide (TiO2) has been commonly used as a photocatalyst owing to its white pigment, excellent photocatalytic activity and low cost; however, its poor pollutant adsorption properties and high electron-hole recombination ratio limit its practical application. Transition metals such as nickel exhibit excellent electron-trapping capability, lowering the rate of electron-hole recombination and facilitating the generation of oxygen free radicals. One-dimensional nanofibers fabricated by electrospinning methods not only develop mesopores but can also make photocatalytic materials with a relatively high specific surface area, thereby increasing the adsorption of pollutants. In this study, transition metal-embedded TiO2 was fabricated by an electrospinning method, and the influence of post-calcination in a reducing atmosphere on the photocatalytic activity was investigated. The photocatalytic properties were performed by decomposition of Rhodamine B under visible light irradiation using fabricated material. Among the investigated samples, Ni-embedded TiO2 nanofibers showed the fastest decomposition of Rhodamine B under visible light irradiation due to a relatively high number of oxygen vacancies, lower Fermi level, small particle size, well-developed mesopores and relatively high specific surface area.