Atomic‐Scale Defected HfS2 Nanosheets: A Novel Platform Enhancing Photocatalysis

Abstract

AbstractRecently, novel 2D materials with fascinating characteristics are extensively applied to design/fabricate high‐activity and cost‐effective photocatalysts for solar‐driven fuels/chemicals generation. Among these 2D materials, HfS2 nanosheets (NSs) exhibit excellent features of large surface area, short bulk‐to‐surface distance, alterable band structures, and vast catalytic sites. Despite these features, no realistic experimental works on HfS2‐based materials are reported in photocatalysis field. Moreover, it is interesting but challenging to realize atomic‐scale engineering of compositions/structures for novel 2D materials and to relate these atomic‐scale characteristics with the element/space/time‐resolved charge kinetics of 2D materials‐based photocatalysts. Herein, for the first time, atomic‐scale defected HfS2 NSs are designed/synthesized. The as‐synthesized HfS2 NSs are combined with various photocatalysts to acquire novel HfS2‐TiO2, HfS2‐CdS, HfS2‐ZnIn2S4, and HfS2‐C3N4 composites, respectively. Among them, HfS2‐CdS exhibits the highest rate (5971 µmol g−1 h−1) on hydrogen (H2) evolution in triethanolamine aqueous solution, together with obviously‐enhanced rates on H2 (2419 µmol g−1 h−1) and benzaldehyde (5.11 mmol g−1 h−1) evolution in benzyl alcohol aqueous solution. Various state‐of‐art characterizations reveal the element/space/time‐resolved electron/hole kinetics in HfS2‐CdS composites, disclosing that these atomic‐scale S vacancies temporarily trapping electrons to facilitate spatiotemporal electron–hole separation/transfer. This work paves avenues to atomic‐scale design/synthesis of new 2D‐materials‐based photocatalysts for sunlight utilization.