A multi-hierarchical 3D conductive construction of a MoP/C-rGO hybrid for a HER catalyst and a LIB anode

Abstract

Construction of molybdenum phosphides (MoP) that are connected to conductive composite materials has been demonstrated to be an effective strategy for improving the activity of MoP, and it is crucial for both the hydrogen evolution reaction (HER) and lithium-ion batteries (LIBs). However, increasing the exposed active sites and simultaneously enhancing the synergistic effect between MoP and the conductive substrate is challenging. Herein, constructing a multi-hierarchical conducting connection based on carbon nanoparticles and reduced graphene oxide (rGO) sheets was proposed. MoP nanoparticles were in situ grown in a carbon matrix to form flower-like MoP/C particles and were well scattered in stable lamellar rGO nanosheets. Benefiting from the conductive network and good dispersion of active sites, the resultant MoP/C-rGO hybrid exhibits efficient HER activity, with Tafel slopes of 69 mV dec⁻¹ and 87 mV dec⁻¹ under acidic and alkaline conditions. Significantly, even when applied as an anode for LIBs, it demonstrates excellent storage performance with a high specific capacity and long-term stability. It displays superior cycle performance of a reversible capacity of 624.6 mA h g⁻¹ at 0.5 A g⁻¹ after 500 cycles. This work provides insight into the construction of multi-hierarchical structures for efficient bifunctional nanostructural electrodes for energy conversion and storage.