Enhancing photocatalytic nitrogen fixation performance of Co-doped bismuth molybdate through band engineering tuning

•Co-doping can boost nitrogen reduction activity of Bi2MoO6 microsphere with the NH3 yield of 130.07 μmol·h−1·gcat-1.•The doping of Co2+ can promoted the rapid separation and transfer efficiency of photogenerated carriers.•The more protons produced were beneficial to participate in the nitrogen reduction reaction.