Mo-/O-deficient Bi2Mo3(S,O)12 oxysulfide for enhanced visible-light photocatalytic H2 evolution and pollutant reduction via in-situ generated protons: A case of material design in converting an oxidative Bi2Mo3O12 catalyst for the reduction

Abstract

The Mo-nonstoichiometry, oxygen vacancy, and S incorporation into Bi-Mo bimetallic oxide enhance the activity by creating defects that improve charge carrier separation efficiency and narrow bandgap energy. Oxygen vacancies synergistically attired nonstoichiometric and Mo-deficient and O-deficient Bi2Mo3-x(S,O)12-y oxysulfide (Mo-/O-deficient Bi2Mo3(S,O)12) is found by a one-pot facile method to enhance the photocatalytic H2 evolution and pollutant reduction via in-situ generated protons. The best Mo-/O-deficient Bi2Mo3(S,O)12 catalyst with x = 0.75 and oxygen vacancy content of 27.6 % produced 480.87 µmol/h H2 with 25 mg catalyst and achieved AQE of 14.26 % at λ = 420 nm, whereas reduced 88.9 % 4-NP and 91.6 % RhB by in-situ generated protons. Bi-non-stoichiometry leads to Mo4+ and oxygen vacancy formation and creates active reaction sites of oxygen vacancy and active surface oxygen. These enhancements benefit photogenerated carrier separation efficiency and fast electron transfer and achieve Mo-/O-deficient Bi2Mo3(S,O)12 with superb PHER. Therefore, non-stoichiometry and sulfur doping into Bi2Mo3O12 bimetallic oxide is a promising approach for designing novel and synergistically defect-attired oxysulfide photocatalysts.