Active Pore-Edge Engineering of Single-Layer Niobium Diselenide Porous Nanosheets Electrode for Hydrogen Evolution

Two-dimensional transition-metal dichalcogenides (TMDs) possess interesting catalytic properties for the electrochemical-assisted hydrogen-evolution reaction (HER). We used niobium diselenide (NbSe₂) as a representative TMD, and prepared single-layer NbSe₂ porous nanosheets (PNS) by a double-sonication liquid-phase exfoliation, with H₂O₂ as a pore-forming agent. The single-layer NbSe₂ PNS were drop-cast on carbon foam (CF) to fabricate a three-dimensional robust NbSe₂ PNS/CF electrode. The NbSe₂ PNS/CF electrode exhibits a high current density of -50 mA cm^-2 with an overpotential of 148 mV and a Tafel slope of 75.8 eV dec^-1 for the HER process. Little deactivation is detected in continuous CV testing up to 20,000 cycles, which suggests that this novel NbSe₂ PNS/CF is a promising catalytic electrode in the HER application. The porous structure of single-layer NbSe₂ nanosheets can enhance the electrochemical performance compared with that of pore-free NbSe₂ nanosheets. These findings illustrate that the single-layer NbSe₂ PNS is a potential electrocatalytic material for HER. More importantly, the electrochemical performance of the NbSe₂ PNS/CF expands the use of two-dimensional TMDs in electrocatalysis-related fields.