Two-dimensional C3N/WS2 vdW heterojunction for direct Z-scheme photocatalytic overall water splitting

The development and design of efficient photoelectric catalysts is of great significance for environmental friendliness. This paper is devoted to finding a new two-dimensional van der Waals heterojunction to realize hydrogen production from water splitting. Based on first-principles calculations, a direct type-Z C3N/WS2 heterojunction was successfully designed by combining highly active two-dimensional transition metal dichalcogenides (TMDs) with C3N similar in structure to graphene. The staggered band structure of the direct Z-scheme and high carrier mobility facilitates the efficient separation of photogenerated electron and hole pairs. More importantly, the C3N/WS2 direct Z-type heterojunction can perfectly realize total water splitting from pH = 0 to pH = 7. What's more, the Gibbs free energy and overpotential demonstrate the excellent hydrogen evolution capability and the oxygen evolution capacity of the material. In summary, these studies provide new ideas for designing high-performance photoelectric catalysts for visible-light water splitting.