Facile synthesis of BiFeO3/Bi2O3 composite photocathode with improved photoelectrochemical performance.

• BiFeO 3 /Bi 2 O 3 composite was successfully fabricated by a facile flame annealing. • The formation of Bi 2 O 3 improves the PEC performance. • The maximum photocurrent of BiFeO 3 /Bi 2 O 3 is two times larger than BiFeO 3. • High PEC performance was attributed to improved light absorption and active sites. BiFeO 3 -based ferroelectrics are promising photoelectrodes for photoelectrochemical (PEC) water splitting. To further enhance its photoelectrocatalytic activity, BiFeO 3 /Bi 2 O 3 composite is designed by a simple and cost-effective flame annealing process in this work. The obtained BiFeO 3 /Bi 2 O 3 photocathode achieves a photocurrent density of −0.21 mA/cm−2 at 0.38 V RHE , with a 160 mV positive shift of the onset potential. Furthermore, the photon-to-current efficiency of BiFeO 3 /Bi 2 O 3 displays an obvious enhancement. The improved PEC performance is due to the formation of composite, which reduces the recombination of carriers, promotes interfacial charge transfer and provides more active sites. Our work provides a promising approach to improve the performance of ferroelectric photoelectrodes. [ABSTRACT FROM AUTHOR]