Modulating Electronic Structure by Etching Strategy to Construct NiSe₂/Ni_0.85Se Heterostructure for Urea‐Assisted Hydrogen Evolution Reaction

Abstract

Exploring and developing novel strategies for constructing heterostructure electrocatalysts is still challenging for water electrolysis. Herein, a creative etching treatment strategy is adopted to construct NiSe2/Ni0.85Se heterostructure. The rich heterointerfaces between NiSe2 and Ni0.85Se emerge strong electronic interaction, which easily induces the electron transfer from NiSe2 to Ni0.85Se, and tunes the charge‐state of NiSe2 and Ni0.85Se. In the NiSe2/Ni0.85Se heterojunction nanomaterial, the higher charge‐state Ni0.85Se is capable of affording partial electrons to combine with hydrogen protons, inducing the rapid formation of H2 molecule. Accordingly, the lower charge‐state NiSe2 in the NiSe2/Ni0.85Se heterojunction nanomaterial is more easily oxidized into high valence state Ni3+ during the oxygen evolution reaction (OER) process, which is beneficial to accelerate the mass/charge transfer and enhance the electrocatalytic activities towards OER. Theoretical calculations indicate that the heterointerfaces are conducive to modulating the electronic structure and optimizing the adsorption energy toward intermediate H* during the hydrogen evolution reaction (HER) process, leading to superior electrocatalytic activities. To expand the application of the NiSe2/Ni0.85Se‐2h electrocatalyst, urea is served as the adjuvant to proceed with the energy‐saving hydrogen production and pollutant degradation, and it is proven to be a brilliant strategy.

NiFe-Based Semi-MOF Embedded by Sulfide Particles Reconstructed a Three-Layer Sandwich Structure for Alkaline Overall Water Splitting

“…It can be inferred that the electrons in the catalyst system moved from Fe and Ni to Co during the vulcanization process, resulting in Co acting as the electron donor of electron-deficient Fe and Ni. The strong charge interaction between the three metal sites further signified the successful construction of the TMS/MOF heterogeneous structure, which effectively adjusted the local electron configuration of the catalyst. − This tunable electronic property can be attributed to (1) the coupling between TMS and MOF due to the coexistence of S 2– sparking strong interfacial interactions, , (2) the electronegativity difference between S in the TMS and O in the MOF (S: 2.58, O: 3.44) showing different abilities to attract electrons, or (3) the Co element having flexible and controllable valences (Co 2+ and Co 3+ ), which is conducive to the transfer of electrons. In conclusion, the S coordination in Co@Ni/Fe-MS/MOF increased the proportion of high-valence Fe and Ni, which are often considered to be highly active sites .…”

Co-doped MnS/NiS/Ni3S2 grown in situ on hydrophilic nickel foam for energy-efficient urea-assisted alkaline hydrogen production

“…Nickel-based electrocatalysts are considered as a promising alternative to noble metal-based catalysts considering their low cost, competitive electrocatalytic activity and excellent catalytic stability, and thus have broad application prospects in urea-assisted water splitting for H 2 production. 24–28 In recent years, various strategies, such as interface engineering, defect engineering, and heteroatom doping, have been applied to simultaneously improve the interfacial charge transfer kinetics and active surface area of catalysts to enhance their catalytic activity. 22,29,30 The heterointerface effect can integrate the active centers of different components to form multi-site reaction pathways for promoting the cleavage of the HO–H bond and accelerate the Volmer step.…”