Novel 2D Zn-porphyrin metal organic frameworks revived CdS for photocatalysis of hydrogen production

Abstract

The main challenge of photocatalysis is how to improve the coefficient of utilization and conversion rate for solar energy. Herein, we report a composite photocatalyst related to a novel porphyrin metal organic frameworks (MOFs), in which cadmium sulfide nanoparticles (CdS NPs) are grown in situ on the surface of two-dimensional (2D) zinc porphyrin nanosheets (Zn-TCPP NSs) by hydrothermal method. Interestingly, Zn-TCPP NSs and CdS NPs form a Type II heterojunction structure, which reduces the photogenerated electron-hole recombination rate of CdS. Moreover, in the near-infrared region, the photo-excited electrons generated by Zn-TCPP NSs are transmitted to CdS NPs, so that cadmium sulfide can realize both visible light and near-infrared light for photocatalytic hydrogen production. The Zn-TCPP NSs not only has excellent light absorption capacity, but also has a unique frame design that effectively reduces the recombination rate of photoinduced electron hole pairs, thus improving the conversion rate of solar energy. As expected, the photocatalytic performance of the porphyrin MOFs modified materials is significantly enhanced compared to CdS NPs. The hydrogen production rate of the Pt@CdS NPs/Zn-TCPP NSs(C-Z-T) composite material in the visible light region is about 15.3 mmol g −1 h −1 , which is 11 times for Pt@CdS NPs. Furthermore, the Pt@CdS NPs/Zn-TCPP NSs(C-Z-T) also has a considerable hydrogen production rate in the near-infrared region, such as 200 μmol g −1 h −1 at 600 nm, 90 μmol g −1 h −1 at 765 nm and 20 μmol g −1 h −1 at > 800 nm. • Provides an idea to simultaneously produce hydrogen in visible light and near-infrared light. • Zn porphyrin MOF has a strong ability to separate photogenerated carriers. • The hydrogen production rate of the composite material under visible light is 11 times more than pure CdS.