Ni doping in unit cell of BiOBr to increase dipole moment and induce spin polarization for promoting CO2 photoreduction via enhanced build-in electric field.

The weak bulit-in electric field of BiOBr material is difficult to promote electron-hole separation, resulting in low photocatalytic CO 2 reduction performance. In this work, Ni has been successfully doped in unit cell of BiOBr and increase the unit cell dipole moment of BiOBr along the x, z directions from 0 to 0.04768 and 0.11293 eÅ, respectively. Enhancement of the unit cell dipole moment induces electron spin polarization near the Fermi energy level, which increases the surface potential from 18 mV to 36.2 mV. When the Ni doping ratio is 3 %, a higher carrier separation efficiency is achieved. 3 %Ni-BiOBr has the excellent CO 2 photoreduction performance with CO yield of 378.7 μmolg−1h−1, which is 4.3 times higher than pure BiOBr (86.75 μmolg−1h−1). Briefly, this research work throws light on enhancing built-in electric field by increasing unit cell dipole moment and inducing spin polarization for improving the photocatalytic performance. [Display omitted] • Ni doping into BiOBr increases the dipole moment and induce the spin polarization to enhance built-in electric field. • 3 %Ni-BiOBr CO 2 photoreduction performance with CO yield is 378.7 μmolg−1h−1. • The CO 2 photoreduction mechanism of 3 %Ni-BiOBr with enhanced electric field is proposed. [ABSTRACT FROM AUTHOR]