Atomic Arrangement in Metal‐Doped NiS₂ Boosts the Hydrogen Evolution Reaction in Alkaline Media

Abstract

We report a novel modulation strategy by introducing transition metals into NiS2 nanosheets (NSs) to flexibly optimize the electronic configurations and atomic arrangement. The Co‐NiS2 NSs exhibit excellent hydrogen evolution reaction (HER) performance with an overpotential of 80 mV at j=10 mA cm−2 and long‐term stability of 90 h in alkaline media. The turnover frequencies (TOFs) of 0.55 and 4.1 s−1 at an overpotential of 100 and 200 mV also confirm their remarkable performance. DFT calculations reveal that the surface dopants abnormally sensitize surface Ni‐3d bands in the long‐range order towards higher electron‐transfer activity, acting as the electron‐depletion center. Meanwhile, the high lying surface S‐sites possess substantially high selectivity for splitting the adsorbing H2O that guarantee the high HER performance within alkaline conditions. This work opens opportunities for enhancing water splitting by atomic‐arrangement‐assisted electronic modulation via a facile doping strategy.

Accurately Regulating the Electronic Structure of NixSey@NC Core–Shell Nanohybrids through Controllable Selenization of a Ni‐MOF for pH‐Universal Hydrogen Evolution Reaction

“…Cyclic voltammetry (CV) curves were also taken under non‐Faradaic conditions, with the capacitance of the electrochemical double layer capacitor ( C dl ) obtained and used to estimate the intrinsic activity of the three samples. [ 44 ] These CV tests were performed with the scanning rates increasing from 20 to 100 mV s −1 and at a voltage test interval of 0.1 V (Figure S14, Supporting Information). The C dl value of Ni 0.85 Se@NC was calculated to be larger (9.4 mF cm −2 ) than those of NiSe@NC (5.4 mF cm −2 ) and NiSe 2 @NC (8.2 mF cm −2 ), which further suggests that high catalytic activity can be achieved through a controllable component‐adjustment strategy (Figure 4d).…”

Optimized Metal Chalcogenides for Boosting Water Splitting

“…The mesoporous FeS 2 with boosting HER performance, if they are also active for OER, it may facilitate the development of overall water splitting. Similarly, Geng's groups reported a mesoporous MnCo 2 O 4 with abundant Mn IV and Co II on the surface, which displayed an excellent performance for reversible oxygen catalysis,250 and indicated potential application in renewable energy technologies and devices. Additionally, the unique synthesis method of spray‐pyrolysis can be used to prepare other mesoporous materials.…”

“…DFT results demonstrate the enhanced charge density and carrier transport with presence of zinc vacancies (V Zn ), while the experiment data display the ZnIn 2 S 4 NSs with abundant V Zn exhibit a superior performance for carbon monoxide formation. Xi's group has developed kinds of 2D nanosheets catalysts, such as NiCo 2 O 4 /NiCoLMO heterogeneous NSs,246 CuFeS 2 ,107 CoFe 2 S 4 ,111 CuCo 2 O 4 ,108 NiFe 2 O 4 /FeNi 2 S 4 ,247 Co‐Fe‐N,248 Ni‐C‐N,249 and M‐NiS 2 NSs250 etc. Recently, they reported metal (Co, Fe, Cu) doped NiS 2 NSs with optimize electronic configuration and atomic arrangement.…”

“…e) Crystal structure of Co‐NiS 2 NSs depicting Ni/Co cations as blue spheres and S in orange; Surface intensity and atomic columns simulated by using QSTEM software along f,g) [101] and h,i) [100] zone axes. Reproduced with permission 250. Copyright 2019, Wiley‐VCH.…”

Synergistically Tuning Electronic Structure of Porous β‐Mo2C Spheres by Co Doping and Mo‐Vacancies Defect Engineering for Optimizing Hydrogen Evolution Reaction Activity

“…Hydrogen is considered as a promising clean and flexible energy carrier and is expected to play a critical role in future sustainable energy. [ 1–5 ] Currently, Hydrogen is mainly extracted from the reforming of traditional hydrocarbons such as diesel, methane and methanol, and the coal gasification process. [ 6–9 ] However, among those processes, massive environment‐unfriendly by‐products (e.g., CO, CO 2 ) are usually generated together with hydrogen production.…”