Bi-Porphyrins MOF with confinement and ion-attracting effects in concert with RuO2-doped CNT as efficient electrocatalysts for HER in acidic and alkaline media

Abstract

It is highly desirable and challenging to design efficient and stable hydrogen evolution reaction (HER) electrocatalysts in a variety of acidic and alkaline media. Here, a novel ternary catalyst has been proposed consisting of ruthenium dioxide doped carbon nanotubes (denoted as RuO2@CNT) wrapped in a multi-step strategy with a first synthesis of a bismuth metal porphyrin-based organic framework as co-catalyst (denoted as RuO2@CNT@MOF). The addition of CNT improves not only the conductivity of the electrocatalyst but also the distribution of the active RuO2 particles. Furthermore, the highly symmetrical conjugated structure of Bi-TCPP MOF facilitates both the adsorption of hydrogen ions and the generation of hydroxyl radicals (•OH). The Bi-TCPP MOF encapsulated in the outer layer of RuO2@CNT enhances the mechanical strength and creates the confinement effect, leading to the synthesis of RuO2@CNT@MOF as a HER electrocatalyst that exhibits excellent catalytic performance and acid and base resistance. In particular, low overpotentials of 13 mV and 50 mV can be achieved to provide current densities of 10 mA cm−2 in alkaline and acidic media, respectively. Significantly, this work provides new ideas for the careful design and development of MOFs as co-catalysts to improve the overall performance of materials in energy-related fields.