Direct coating of a g-C3N4 layer onto one-dimensional TiO2 nanocluster/nanorod films for photoactive applications

Abstract

We report the coating of metal-free graphitic carbon nitride (g-C₃N₄) onto titanium dioxide (TiO₂) nanorods via a thermal evaporation method. Prior to g-C₃N₄ coating, TiO₂ nanoclusters were grown on TiO₂ nanorods to enhance the surface area by dipping in a TiCl₃ solution for 12, 24 and 36 h. The prepared films were analyzed to assess the improvement in absorbance and reduction in recombination losses. Nanoclustered TiO₂ grown for 24 h and then coated with a g-C₃N₄ film (i.e., TC_24h_CN) had the highest photocurrent of 235 and 290 μA, respectively, when measured by transient photocurrent and linear sweep voltammetry techniques. The enhanced performance resulted from a reduced recombination of electron–hole pairs. The TC_24h_CN film displayed an excellent photoresponse over 15 h of exposure to visible light and hence could potentially be used in water purification device technology.