Low proton adsorption energy barrier of S-scheme p-CNQDs/VO-ZnO for thermodynamics and kinetics favorable hydrogen evolution

Traditional photocatalytic hydrogen evolution path with high energy barrier of proton adsorption limits the reaction efficiency. Specific regulation on active site to realize low energy barrier hydrogen generation provides a new perspective. In this work, an innovative low barrier route is provided on protonated N of g-C3N4 of S-scheme protonated g-C3N4 quantum dots/ZnO hybrid rich in oxygen vacancies (p-CNQDs/VO-ZnO). VO generated by quantum dots doping optimizes the electron structure of S-scheme, whereas the intensive electron directional transmission in S-scheme promotes protonation of p-CNQDs. Profited from the synergies of thermodynamic and dynamic, protons and electrons concentrate at edge-active N accomplish the efficient photocatalytic HER with a 117-fold elevated H2 evolution. This work provides more possibilities for designing low energy pathway and efficient catalyst in H2 evolution reaction.