Mo(S,O)/(Ce,Mo)(S,O) sulfo-oxide with heterovalent metal states for efficient visible-light-driven hydrogen evolution and pollutant reduction via in-situ generated protons

The existence of the heterovalent metal states and S doping into Ce-Mo bimetallic oxide improve the photocatalytic activity by generating oxygen vacancy and narrowing the bandgap for suitable water splitting. Spherical and plate likes heterostructure Mo(S,O)/ (Ce,Mo)(S,O) sulfo-oxide catalysts with heterovalent metal states and oxygen vacancy de-fects were synthesized by co-precipitation method for photocatalytic hydrogen evolution reaction. Catalyst labeled as 1-CeMoOS with more oxygen vacancies and high Ce3+/ (Ce3++Ce4+) ratio evolved 405.18 mmol/h H2 and achieved AQE of 13.72%, whereas reduced 76.43% 4-NP and 91.52% RhB by in-situ generated protons. S doping, oxygen vacancy cre-ation, Ce and Mo heterovalent states have narrowed the bandgap by substituting oxygen with sulfur, promoted the photogenerated charge carriers' effective separation, and pro-longed the lifetime of electrons. The oxygen vacancy formation with a subsequently partial Ce4+-to-Ce3+ conversion achieves CeMoOS catalysts with excellent PHER and provides a promising way to improve photocatalysts' visible light PHER activity.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.