A Au nanoparticle anchored stannatranone-pillared MOF as a duo-active electrocatalyst for overall water splitting

Abstract

The design and construction of a duo-active electrocatalyst with effective performance and enhanced stability for overall water splitting have been in the spotlight to meet the demand for renewable energy. Herein, we report the fabrication of a stannatranone pillared metal–organic framework via a coprecipitation approach and further its decoration with gold nanoparticles (size ≅ 10.86 nm) for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The Au-anchored Sn–Na MOF (Au NPs/Sn–Na MOF) exhibited a remarkable electric activity with low overpotential (η) of 129 mV for the HER at a current density of 10 mA cm⁻², and 650 mV for the OER at a current density of 20 mA cm⁻². The slope values were found to be 62.3 mV dec⁻¹ and 37.8 mV dec⁻¹, respectively. The heightened OER and HER activities can be ascribed to its substantial electrochemically active surface area of 17.4 mF cm⁻². The mechanistic studies revealed that Au NPs/Sn–Na MOF provides active surface sites for water adsorption and facilitates subsequent dissociation to form H₂ and O₂. Furthermore, the pillared structure of the MOF with stannatranone knots made the skeleton highly stable under basic conditions for its potential application in overall water splitting.