Synthesis and characterization of TiO2/CuS nanocomposite fibers as a visible light-driven photocatalyst

Abstract

TiO2/CuS nanocomposites were fabricated by precipitation of nanosized CuS via sonochemical method on electrospun TiO2 nanofibers, and their structure, chemical bonding states, optical properties, and photocatalytic activity were investigated. In the TiO2/CuS nanocomposite, the position of the conduction band for CuS was at a more negative than that of TiO; meanwhile, the position of the valence band for CuS was more positive than those for TiO, indicating a heterojunction structure belonging to type-II band alignment. Photocatalytic activity, measured by decomposition of methylene blue under visible-light irradiation (λ > 400 nm) for the TiO2/CuS nanocomposite, showed a value of 85.94% at 653 nm, which represented an improvement of 52% compared to that for single TiO2 nanofiber (44.97% at 653 nm). Consequently, the photocatalyst with TiO2/CuS nanocomposite had excellent photocatalytic activity for methylene blue under visible-light irradiation, which could be explained by the formation of a heterojunction structure and improvement of the surface reaction by increase in surface area.