Ultrathin MOF Coupling with Molecular Cobaloxime to Construct an Efficient Hybrid Hematite Photoanode for Photocatalytic Water Splitting

It is a great challenge to develop efficient artificial photosynthesis systems by mimicking natural photosynthesis. In this present work, an organo-inorganic hybrid photoanode was fabricated by depositing ultrathin NiFe MOF nanolayers and molecular cobaloxime cocatalyst on the surface of Ti-doped porous hematite (Ti-PH). This hybrid photoanode exhibited a high photocurrent density of 2.45 mA/cm(2) at 1.23 V vs the reversible hydrogen electrode (RHE) under AM 1.5 G illumination with excellent stability. Moreover, the optimal incident photon-to-current efficiency (IPCE) of the hybrid photoanode reached 83.0% at 365 nm and the surface charge injection efficiency (eta(inj)) was improved to 87.5% at 1.23 V vs RHE. Detailed investigations reveal that NiFe MOFs can effectively facilitate charge separation as a hole-transport layer and molecular cobaloxime cocatalyst can passivate surface trap states to increase water oxidation kinetics.

Automated summary

This study successfully fabricated an organo-inorganic hybrid photoanode with high photocurrent density and stability. Further investigations revealed that NiFe MOFs and molecular cobaloxime cocatalyst effectively facilitate charge separation and improve water oxidation kinetics, respectively.