Flexible self-supporting bifunctional [TiO2/C]//[Bi2WO6/C] carbon-based Janus nanofiber heterojunction photocatalysts for efficient hydrogen evolution and degradation of organic pollutant

Abstract

A novel [TiO2/C]//[Bi2WO6/C] carbon-based Janus nanofiber heterojunction photocatalyst (denoted as JNHP) was designed and constructed via conjugate electrospinning combined with subsequent calcination process. The JNHP with unique Janus structure has two sides: one side is TiO2/C nanofiber which responds to ultraviolet light, the other side is Bi2WO6/C nanofiber responding to visible light, thus effectively utilizing sunlight. JNHP possesses excellent bi-functionality of photocatalytic hydrogen production and methylene blue (MB) degradation. Hydrogen production rates of JNHP reach respectively as high as 11.58 and 16.32 mmol h−1 g−1 under visible light and simulated sunlight irradiation, and no noble metal is needed to add as cocatalyst in the process of hydrogen production, and further the photo-degradation rates of MB respectively are 93.3% (160 min) and 97.9% (140 min). Compared with counterpart TiO2/C and Bi2WO6/C carbon-based nanofiber photocatalysts, enhanced photocatalytic performance of JNHP mainly results from the synergistic effect of unique heterojunctions between TiO2 and Bi2WO6 and one-dimensional conductive carbon nanofiber (CNFs). Furthermore, JNHP with one-dimensional flexible self-supporting structure can be easily separated from the solution and has excellent recyclable stability. The proposed designing philosophy and preparation approach have guiding significance for the development of other one-dimensional bifunctional nanofiber photocatalysts.