Direct Z-scheme Fe2(MoO4)3/MoO3 heterojunction: Photo-Fenton reaction and mechanism comprehension

•Formation mechanism of “brick-like” Fe2(MoO4)3/MoO3 heterojunction is investigated.•Inner electric field built at interface is beneficial for Z-scheme path of electron.•H2O2 acts as oxidant in Fenton reaction and e- scavenger in photocatalytic reaction.•k is 0.107 min−1 in photo-Fenton reaction, 170 times higher than photocatalysis.•1140% of extra efficiency is yielded by coupling Fenton reaction and photocatalysis.