Ternary-role of NiCo-MOFs for boosting the photocatalytic H2-evolution and long term stability of CdS

CdS is a promising candidate for visible-light-driven photocatalytic H2-evolution, but its practical application is still limited by self-photo-corrosion and noble co-catalysts needing. Herein, CdS/NiCo-MOFs (CM) heterojunction was synthesized by an in-situ hydrothermal method, where NiCo-MOFs (BMOFs) acted as platform to inhibit the aggregation of CdS nanoparticles. Furthermore, BMOFs provided dual-reaction sites to improve the photocatalytic H2-evolution speed and suppress the photo-corrosion of CdS by taking its Ni-linker as catalytic active sites for water splitting and Co-linker as hole trapping sites to suppress the self-oxidation between S2− and holes. Therefore, the optimal CM-20% exhibited a remarkable photocatalytic H2-evolution rate of 1.810 mmol g−1 h−1 under sunlight irradiation, which is 4.55 times higher than that of CdS. Moreover, CM-20% maintained this high photocatalytic H2-evolution rate for 100 h reaction, which for CdS is just 50 h. This research provides insight into designing high-efficiency and photo-stable sulfide-based photocatalyst systems for H2-evolution.