A synergistic effect between S-scheme heterojunction and Noble-metal free cocatalyst to promote the hydrogen evolution of ZnO/CdS/MoS2 photocatalyst

Assembling the composition synergism and structure adjustment to efficiently accelerate the charge transfer and separation, is emerging as a promising strategy for advanced photocatalytic H2 evolution. Herein, an efficient ZnO/CdS/MoS2 photocatalyst with similar componments crystal structures and integrated S-scheme heterojunction and cocatalyst effects, was constructed to synergistically promote the photocatalytic H2 evolution of CdS. The optimized ZnO/CdS/MoS2 heterojunction with an MoS2 mass ratio of 6 wt% (ZCM-3) revealed the highest H2 evolution rate of 10247.4 μmol g−1h−1, 30.7-fold and 3.0-fold higher than that of bare CdS (323.5 μmol g−1h−1) and optimized ZnO/CdS (3400.8 μmol g−1h−1), respectively. Moreover, the slight change in H2 production activities and retained crystal structures after five consecutive cycles indicate the stability of the photocatalyst. Detailed experimental results and DFT calculation elucidated that the substantially boosted photocatalytic performance was originated not only from the fast electron transfer and separation through the intimate contact, but also the synergistic effect between the S-scheme and cocatalyst. A possible mechanism was speculated based on the results, which can enriche the research for S-scheme heterojunction photocatalytic system and provide new insights for the design of efficient H2 production photocatalyst.