Plasmonic hot charge carriers activated Ni centres of metal–organic frameworks for the oxygen evolution reaction

Abstract

Water splitting for the oxygen evolution reaction (OER) through electrocatalysis holds significant promise for energy conversion. However, its real application is yet hindered owing to the lack of efficient electrocatalysts. Herein, we propose a plasmon activation approach for the acceleration of the OER on a Au nanorod–2D ultrathin metal–organic framework (NiCo-MOF) hybrid. The plasmon-generated hot holes of Au nanorods (AuNRs) can be injected into the nickel active sites of the OER catalyst, significantly increasing the generation of high valence Ni* active species in NiCo-MOFs with better matched energy levels for the OER, in turn decreasing the OER activation energy. Thus, excellent OER performance of the NiCo-MOFs under surface plasmon resonance of AuNRs is achieved with an overpotential of 240 mV at a current density of 10 mA cm⁻² and a Tafel slope of 69 mV dec⁻¹, which is much better than that of the reported catalysts. This finding highlights the importance of noble metal LSPR in facilitating the OER performance of MOFs and opens up a new avenue for improving the intrinsic electrocatalytic activity of pristine MOFs.