Applied Catalysis B: Environmental, Vol.241, 483-490, 2019
In-situ hydrogenation engineering of ZnIn2S4 for promoted visible-light water splitting
Hydrogenation engineering has been considered as one of the promising methodologies to significantly enhance the visible light absorption and photocatalytic activities of semiconductor photocatalyst. However, hydrogenated catalyst with remarkably elevated photocatalytic activity has been commonly obtained so far under severe conditions such as high temperatures or pressures and huge doses of H-2 or plasma activation with complex treatment. Here, we proposed in-situ hydrogenated ZnIn2S4 (H(x)ZIS) obtained at room temperature under UV-vis light illumination within several hours. This extremely facile hydrogenation strategy is based on the discovered fact that H could spontaneously adsorb on the ZnIn2S4 (ZIS) surface to generate durable point defects and even surface disorder, resulting in the largely enhanced solar energy utilization of ZIS. As a result, the hydrogenation engineered the band gap from 2.42 to 1.51 eV, while the optimal bandgap was tuned to ca. 2.08 eV with a -10-fold photocatalytic activity promotion. This study is the first paradigm of in-situ hydrogenation of inorganic metal chalcogenide, and we believe that such a facile and general methodology will open up a new pathway to create high-efficiency photocatalyst.