A dual optimization approach for photoreduction of CO2 to alcohol in g-C3N4/BaTiO3 system: Heterojunction construction and ferroelectric polarization

The improved separation efficiency of photogenerated electrons and holes is an effective way to improve photocatalytic performance. Herein, the high efficiency sheet/fiber g-C3N4/BaTiO3 photocatalysts with built-in electric field are successfully synthesized by electrospinning and simple calcination method. Compared with pure g-C3N4 and BaTiO3, g-C3N4/BaTiO3 heterojunction possesses higher photogenerated electron-hole pairs separation efficiency and larger specific surface area, thus improving the photocatalytic activity of g-C3N4/BaTiO3 catalysts. Besides, the ferroelectric polarization produced by external electric field significantly promotes the CO2 reduction performance of CNBT20 [the component with mass fractions BT / (CN/BT) = 20 %], whose reduction rates of CH3OH and CH3CH2OH are 1.44 and 1.50 times that of unpolarized CNBT20, accompanied with remarkable cyclic stability. The coupling effect of heterojunction and ferroelectric polarization improves the separation efficiency of photoexcited carriers in g-C3N4/BaTiO3 significantly, hence providing broad prospects for the combination of traditional semiconductors and ferroelectric materials to improve photocatalytic performance.