Preparation and Photocatalytic Activity for Hydrogen Evolution of Graphene-ZnIn$lt;inf$gt;2$lt;/inf$gt;S$lt;inf$gt;4$lt;/inf$gt; Nanocomposite Spheres

Graphene-ZnIn 2 S 4 nanocomposite spheres were prepared via a facile photocatalytic reduction method. The samples were characterized by XRD, SEM, TEM, FT-IR, XPS and DRS. The results showed that the graphene oxide was reduced to graphene and ZnIn 2 S 4 nanospheres were loaded on the surface of graphene sheets through a photocatalytic reduction process. The experimental results for photocatalytic hydrogen evolution of the samples indicated that the amount of evoluted H 2 under simulated sunlight irradiation using graphene-ZnIn 2 S 4 nanocomposite spheres was 1540.8 mol, 9.8 times of the pure ZnIn 2 S 4 nanospheres, under optimal technological condition with the graphene content of 2.0wt% for 24 h. The enhanced performance can be attributed to the graphene which effectively promoted the transfer of photogenerated electrons. Furthermore, a detailed photocatalytic hydrogen evolution mechanism of graphene-ZnIn 2 S 4 nanocomposite spheres was investigated.