Well-designed three-dimensional hierarchical hollow tubular g-C3N4/ZnIn2S4 nanosheets heterostructure for achieving efficient visible-light photocatalytic hydrogen evolution

Photocatalytic water splitting for hydrogen production is an important strategy to achieve clean energy development. In this report, a novel three-dimensional (3D) hierarchical hollow tubular g-C3N4/ZnIn2S4 nanosheets (HTCN/ZIS) type-Ⅱ heterojunction photocatalyst was successfully prepared and applied for photocatalytic hydrogen production under visible light irradiation. The experimental results reveal that the optimal proportion of HTCN/ZIS with the remarkable photocatalytic H2 evolution rate of 20738 μmol h-1 g-1 was obtained. The main reasons for the improvement of hydrogen production activity are as follows: (i) this unique tubular hollow structure can effectively enhances the light capturing ability by the multiple light scattering/reflection of incident light in the inner cavity; (ii) the shorten the phase plane transmission distance could reduce the path of charge transfer; (iii) the surface coated a large number of scaly ZnIn2S4 nanosheets can provide abundant reactive sites. Combining the various characterization tests, the enhanced spatial segregation of charge carriers could owning to the intimately interfacial contact and well-matched band gaps structure between g-C3N4 and ZnIn2S4 through the type-II heterojunction. This work provides a new prospect for the construction of a novel 3D hierarchical type-II heterojunction photocatalyst for highly efficient photocatalytic hydrogen production.