Boosting light harvesting and charge separation in 3D porous WS2@C@ZnIn2S4 skeleton heterojunction for efficient solar fuels production

The reasonably designed 3D porous WS 2 @C@ZnIn 2 S 4 skeleton heterojunction photocatalyst has many structural merits, which are beneficial for enhancing the light-harvesting efficiency and providing interfacial charge-transfer pathways as well as facilitating mass transfer. These synergistic effects ensures that the surviving photo-excited charge carriers can reach more active sites, thus resulting in considerable photocatalytic H 2 evolution and CH 4 production performance, respectively. • A novel 3D porous WS 2 @C@ZnIn 2 S 4 skeleton heterojunction successfully synthesized. • The optimal photocatalyst exhibits considerable H 2 and CH 4 production performance. • The multiple diffuse reflection effect ensures broad light-harvesting property. • Photocatalytic mechanism was investigated by experimental and theoretical aspects. Construction of photocatalysts with efficient light-harvesting and charge separation properties for boosting photocatalytic hydrogen (H 2 ) evolution is still a challenge. Herein, a three-dimensional (3D) porous WS 2 @C@ZnIn 2 S 4 skeleton heterojunction is successfully synthesized by epitaxial growth of ZnIn 2 S 4 nanosheets on the WS 2 @C skeleton. The optimal WS 2 @C@ZnIn 2 S 4 photocatalyst exhibits considerable photocatalytic H 2 evolution rate (11.15 mmol·g −1 ·h −1 ) and CO 2 -to-CH 4 production performance (43.29 μmol·g −1 ), respectively. The high photocatalytic performance can be ascribed to the fact that multiple light reflection and scattering behaviors originated from 3D architecture facilitates to prolong the interaction length between photons and catalyst, which significantly enlarging the light-harvesting ability and utilization efficiency. Importantly, highly conductive WS 2 @C skeleton can drive photo-induced charge transportation from ZnIn 2 S 4 to WS 2 co-catalyst via the interfacial charge-transfer pathways. The DFT calculations further demonstrate the promotional effects of multiple diffuse reflection and separation of photo-generated carriers in photocatalytic H 2 evolution.