A molybdenum sulfo-oxide/cobalt oxysulfide Z-scheme heterojunction catalyst for efficient photocatalytic hydrogen production and pollutant reduction

Abstract

The existence of a heterojunction in the catalyst structure improves the efficiency of photocatalytic hydrogen production. The two phases of the heterojunction can be adjusted simultaneously by doping sulfur and oxygen to achieve a suitable energy band structure. Herein, we demonstrated a Mo(S,O)/Co(O,S) Z-scheme heterojunction catalyst system (abbreviated as MoCoOS) with different Co(O,S) doping amounts by a simple one-step method. Doping of different atoms in the crystal changes the energy band structure which tunes the optical, electrical, and electrochemical properties of MoCoOS. MoCoOS-2 prepared at a Co precursor content of 20 mmol performed the best at a rate of 153.4 μmol h⁻¹ in photocatalytic hydrogen evolution, and it also showed excellent catalytic activities and good stability in reducing MO, MB, RhB, 4-NP and Cr⁶⁺. This efficient MoCoOS-2 catalyst can have practical applications in photocatalytic hydrogen production and catalytic reduction of chemical pollutants.