Flower-like S-doped-Ni₂P mesoporous nanosheet-derived self-standing electrocatalytic electrode for boosting hydrogen...

Developing cost-effective, highly active, and stable electrocatalysts for boosting electrochemical hydrogen evolution reaction (HER) in alkaline media is playing a critical role in meeting the demands of the hydrogen industry in the future. Herein, an efficient HER electrocatalyst based on flowerlike S-doped Ni₂P mesoporous nanosheets (NSs) supported on nickel foam (S-Ni₂P NSs/NF) was developed through an effective approach. The obtained S-Ni₂P NSs/NF catalyst required low overpotential of only 87.5 and 179.1 mV to reach a current density of 10 and 50 mA cm^-2, respectively. Moreover, a small Tafel slope of 62.1 mV dec^-1 for S-Ni₂P NSs/NF demonstrated that the HER process occurred with very fast kinetics. Besides high HER activity, the synthesized S-Ni₂P NSs/NF catalyst exhibited superior stability and long-term durability towards HER, which had the ability to operate for over 30 h without degradation in catalytic performance. The unique flower-like nanosheet structure with excellent mesoporous characteristics of S-Ni₂P NSs/NF resulted in maximizing the electrochemical active surface area for providing a large number of electrocatalytic active sites. In addition, the S-doping effect could modulate the electronic structure of Ni species in Ni₂P, leading to an acceleration of the adsorption rate of reaction intermediates on the surface of catalysts towards improving HER kinetics. The results not only demonstrate S-Ni₂P NSs/NF as an active catalyst for HER, but offer an effective strategy for improving the catalytic activity of earth-abundant transition metal-based HER catalysts.