Fabrication of 2D SnS/g-CN heterojunction with enhanced H evolution during photocatalytic water splitting.

In this work, the 2D SnS/g-CN heterojunctions were successfully prepared by heating the homogeneous dispersion of SnS nanosheets and g-CN nanosheets using a microwave muffle. SEM, TEM and HRTEM images indicated that the SnS nanosheets were loaded on the surface of the g-CN nanosheets. The UV-vis spectra show that the absorption intensity of the as-prepared samples was increased and the absorption range was also extended from 420 nm to approximately 600 nm. The H production rate over 5 wt% SnS/g-CN can reach 972.6 μmol·h·g under visible light irradiation (λ > 420 nm) using TEOA as the sacrifice agent and Pt as the electron trap, which is 2.9 and 25.6 times higher than those of the pristine g-CN and SnS, respectively. According to the obtained PL spectra, photocurrent and EIS spectra, the enhanced performance for H generation over the heterojunctions is primarily ascribed to the rapid charge transfer arising from the suitable band gap positions leading to an improved photocatalytic performance. The recycling experiments indicated that the as-prepared composites exhibit good stability in H production. Additionally, a possible enhanced mechanism for H evolution was deduced based on the results obtained by various characterization techniques.