Enhancement of Interfacial Charge Transportation Through Construction of 2D–2D p–n Heterojunctions in Hierarchical 3D CNFs/MoS2/ZnIn2S4 Composites to Enable High‐Efficiency Photocatalytic Hydrogen Evolution

Abstract

Hierarchical three‐dimensional (3D) carbon nanofibers (CNFs)/molybdenum disulfide (MoS2)/ZnIn2S4 composites with p–n heterojunctions between the basal planes of two‐dimensional (2D) phases are fabricated, using in situ spinning‐based chemical vapor deposition together with hydrothermal processing. It is found that large and intimately interfaced 2D–2D planes between the n‐type ZnIn2S4 and the CNFs‐supported p‐type MoS2 enable evident junction rectification effect, which facilitates interfacial charge separation to assist effective suppression of the recombination of photogenerated electrons and holes. In addition, the p‐type MoS2 nanosheets with high in‐plane conductivity and narrower bandgap are highly effective in providing larger quantities of photoinduced electrons, which can be readily injected into the outer n‐type ZnIn2S4 coating for the reduction of H2O into H2, whereas the holes are driven into the CNF cores by the junction field to be finally scavenged. The large specific surficial area of the sulfides provides abundant sulfur‐rich sites active for H2 evolution. Consequently, the optimal CNFs/MoS2/ZnIn2S4 composite with 5 mmoL MoS2 loading exhibits robust H2 evolution under simulate sunlight irradiation, achieving a remarkably enhanced photocatalytic H2 production rate over 151.42 mmoL⋅h−1⋅g−1 and a high apparent quantum yield of 20.88% at 365 nm, which is 4.65 times higher than that of pristine ZnIn2S4.