Boosting photocatalytic hydrogen evolution by engineering a Yb-O-Ti electron bridge in ytterbium metalloporphyrin MOFs nanohybrid

It is vital how to increase the activity and stability of metal–organic frameworks (MOF) in photoelectric conversion and photocatalytic hydrogen evolution. In this study, we focused on the preparation of two-dimensional copper-ytterbium metalloporphyrin MOF (Cu-Yb PMOF, using ytterbium ion as the metal linker and copper tetracarboxyphenylporphyrin as the ligand) coated with uniform TiO 2 nanoparticle layer by means of Yb-O-Ti bond. Importantly, the photocatalytic activity of H 2 generation over the Cu-Yb PMOF/TiO 2 -150 can achieved 5424.3 μmol g −1 h −1 , which was 53.87 and 34.59 times higher than that of the original Cu-Yb PMOF and TiO 2 , respectively. Moreover, the nanohybrid showed an 40 % improved stability compared to Cu-Yb PMOF. Combined with Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectra (XPS), electron paramagnetic resonance (EPR), and Finite-Difference Time-Domain (FDTD), it was demonstrated that the Z-type electron transfer in the nanohybrid can be greatly enhanced by the formed Yb-O-Ti bond, yielding a substantial increase in the photocatalytic activity and stability for H 2 generation.