Stable metal-organic framework (MOF) integrated BCZT for improved photo-electrochemical water splitting

We report enhancement in the photo-electrochemical properties of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) coupled with a copper-based metal-organic framework (Cu-MOF). The optical bandgap (Eg) of BCZT reduces to 2.2 eV from 2.8 eV after Cu-MOF coupling, leading to increased visible light absorption in the Cu-MOF/BCZT composite. The photo-current was enhanced from 20 mu A/cm2 to 80 mu A/cm2(-4 times higher) in the Cu-MOF/BCZT composite under visible light illumination. The enhancement in the photo-current was well supported by enhancement in incident photon to current conversion efficiency (IPCE), electrochemical impedance spectroscopy (EIS), and Mott-Schottky measurements, respectively. The porous structure of the Cu-MOF enhances change transfer properties in the Cu-MOF/BCZT composite,which is a critical factor for the observed enhancement in the photoelectrochemical properties. This work provides a novel strategy for combining MOFs with photo-absorbing materials to design future solar-to-hydrogen conversion devices.