Facile synthesis of Zn 0.5 Cd 0.5 S nanosheets with tunable S vacancies for highly efficient photocatalytic hydrogen evolution.

In order to effectively improve the separation efficiency of photogenerated charge carriers and thus the photocatalytic activity, in this work, porous Zn 0.5 Cd 0.5 S nanosheets with a controlled amount of S vacancies were prepared by a multistep chemical transformation strategy using the inorganic-organic hybrid ZnS-ethylenediamine (denoted as ZnS(en) 0.5 ) as a hard template. The amount of S vacancies and the morphology of the Zn 0.5 Cd 0.5 S nanostructures were tailored by adjusting the hydrolysis time. Furthermore, we report the observation of S vacancies in porous Zn 0.5 Cd 0.5 S nanosheets at the atomic level using spherical aberration-corrected (Cs-aberrated) transmission electron microscopy (Cs-corrected-TEM). The results revealed that Zn 0.5 Cd 0.5 S nanosheets with S vacancies absorb more visible light and generate more electron-hole carriers due to their porous nanosheet structure. At the same time, sulfur vacancies are introduced into the Zn 0.5 Cd 0.5 S nanosheets to capture the electrons generated by the light and further extend the lifetime of the carriers. As expected, the photocatalytic activity of Zn 0.5 Cd 0.5 S nanosheets prepared by 4 h hydrolysis is 20.5 times higher than that of Zn 0.5 Cd 0.5 S(en) x intermediates. Moreover, Zn 0.5 Cd 0.5 S-4h showed excellent cycling stability. This work provides a new strategy for the optimization of Zn 0.5 Cd 0.5 S photocatalysts to improve photocatalytic hydrogen evolution.