Bimetallic MIL-88/Polyaniline Hybrid Hollow Structure: In-situ Synthesis and Enhanced Oxygen Evolution Reaction at...

Developing oxygen evolution reaction (OER) electrocatalysts in an efficient strategy, while maintaining high catalytic activity and stability under high current densities, remains a crucial problem. In this study, a bimetallic iron-cobalt phytic acid complex loaded with polyaniline hollow structure (FCP@PAn) was successfully constructed, via a progress of selective etching and surface modification in one step without high-temperature phosphating or carbonization. The as-obtained FCP@PAn required only 329 and 385 mV overpotentials at high current densities of 500 and 1000 mA cm^-2, respectively, due to phytic acid and polyaniline incorporation and the coordinated effect of each component. Additionally, the FCP@PAn exhibited the lowest Tafel slope values of 44.6 mV dec^-1 and was able to continuously operate for 120 h at 500 mA cm^-2, displaying high catalytic activity and stability. Hence, the hollow structure of the conductive polymer and MOFs composites provided a new surface modification strategy for transition metal-based catalysts that are prone to dissolution or corrosion during the OER process, as well as for high current density applications.