Rational Design and Controlled Synthesis of V‐Doped Ni₃S₂/Ni_xP_y Heterostructured Nanosheets for the Hydrogen Evolution Reaction

Abstract

Rational construction of high‐efficiency and low‐cost catalysts is one of the most promising ways to produce hydrogen but remains a huge challenge. Herein, interface engineering and heteroatom doping were used to synthesize V‐doped sulfide/phosphide heterostructures on nickel foam (V‐Ni3S2/NixPy/NF) by phosphating treatment at low temperature. The incorporation of V can adjust the electronic structure of Ni3S2, expose more active sites, and protect the 3D structure of Ni foam from damage. Meanwhile, the heterogeneous interface formed between Ni3S2 and NixPy can provide abundant active sites and accelerate electron transfer. As a result, the V‐Ni3S2/NixPy/NF nanosheet catalyst exhibits outstanding activity in the hydrogen evolution reaction (HER) with an extremely low overpotential of 90 mV at a current density of 10 mA cm−2 and stable durability in alkaline solution, which exceeds those most of the previously reported Ni‐based materials. This work shows that rational design by interfacial engineering and metal‐atom incorporation has a significant influence for efficient hydrogen evolution.

Amorphous–Crystalline Heterostructure with Ample Oxygen Vacancy In Situ Evolved from Heterojunction Ni(OH)2@V–Ni3S2/NF toward Efficient Water Electrolysis

“…Therefore, the real catalyst after the evolution of the HER is V–NiOOH/Ni­(OH) 2 @V–Ni 3 S 2 /NF. As reported by previous works, , the increased V doping in the catalyst can improve the electronic structure in the electrode and boost the free carrier density near the Fermi level, promoting the HER catalytic capacity.…”

“…Therefore, the real catalyst after the evolution of the HER is V−NiOOH/Ni(OH) 2 @V−Ni 3 S 2 /NF. As reported by previous works, 6,7 the increased V doping in the catalyst can improve the electronic structure in the electrode and boost the free carrier density near the Fermi level, promoting the HER catalytic capacity. XPS analysis was employed for the sake of detecting the variation of chemical states of elements in Ni(OH) 2 @V− Ni 3 S 2 /NF after the evolution of the OER and HER (Figure 6).…”

“…They found that the V doping in Ni 3 S 2 enhanced the free carrier density near the Fermi level, leading to a great improvement in the catalytic activity of HER. Wang et al synthesized a V-doping Ni 3 S 2 /Ni x P y heterostructure grown on nickel foam for HER and proved that the dopant of V could add the active sites and activate adjacent metal atoms . Besides, V-doped Ni 3 S 2 is also regarded as a vital OER catalyst for water splitting.…”

“…Wang et al synthesized a Vdoping Ni 3 S 2 /Ni x P y heterostructure grown on nickel foam for HER and proved that the dopant of V could add the active sites and activate adjacent metal atoms. 7 Besides, V-doped Ni 3 S 2 is also regarded as a vital OER catalyst for water splitting.…”