Computational and experimental investigation of Co and S-doped Ni2P as an efficient electrocatalyst for acid mediated proton exchange membrane hydrogen evolution reaction

摘要: Engineering earth-abundant and high performance electrocatalysts to facilitate the hydrogen evolution reaction (HER) for generation of sustainable fuel has been a major scientific technological challenge in electrolytic water splitting area. Herein, employing theoretical first principles calculations HER thermodynamics kinetics-based density functional theory (DFT), we report platinum group metal (PGM)-free Co S containing Ni2P [(Ni0.95Co0.05)2P:x at% (x = 5, 10, 15)] system as highly active robust acidic HER. On basis DFT calculations, (Ni0.95Co0.05)2P:15S composition reveals optimal adsorption free energies (ΔGH*) beneficial modification surface electronic structure. Accordingly, electrocatalyst, synthesized via simple facile low temperature solid state approach, demonstrates significantly higher comparison pristine comparable state-of-the-art Pt/C electrocatalyst. Owing unique structure i.e. change states (DOS) optimized ΔGH*, exhibits considerably lower charge transfer resistance (6.82 Ω cm2), overpotential (44 mV at 10 mA cm−2), smaller Tafel slope (31.25 dec−1), contact angle (7°) correspondingly, bubble break-off diameter (0.38 mm) with mass activity (43.75 A g−1 −0.05 V) (Ni0.95Co0.05)2P:x 0, 10) Ni2P. The composition, also displays long term electrochemical stability, similar Pt/C, no degradation its activity, reflective excellent structural robustness Consequently, present experimental study fortified by provides novel synergistic insights into designing promising efficient multi-component electrocatalysts.