Electron Density Modulation of MoO₂/Ni to Produce Superior Hydrogen Evolution and Oxidation Activities

Abstract

Hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) have aroused great interest, but the high price of platinum group metals (PGMs) limits their development.The electronic reconstruction at the interface of a heterostructure is a promising strategy to enhance their catalytic performance. Here, MoO 2 /Ni heterostructure was synthesized to provide effective HER in an alkaline electrolyte and exhibit excellent HOR performance. Theoretical and experimental analyses prove that the electron density around the Ni atom is reduced. The electron density modulation optimizes the hydrogen adsorption and hydroxide adsorption free energy, which can effectively improve the activity of both HER and HOR. Accordingly, the prepared MoO 2 /Ni@NF catalyst reveals robust HER activity (η 10 = 50.48 mV) and HOR activity (j 0 = ∼1.21 mA cm −2 ). This work demonstrates an effective method to design heterostructure interfaces and tailor the surface electronic structure to improve HER/HOR performance.

Substitutional Doping Engineering toward W2N Nanorod for Hydrogen Evolution Reaction at High Current Density

“…The calculation structure is exhibited in Figure S25. Figure a demonstrates that the calculated Δ G H * value of Ni-W 2 N is only −0.175 eV, which is close to the first-rank value of 0 eV. , Pure W 2 N has too strong an affinity for H* (−0.256 eV). What is more, Ni-W 2 N has an excellent Δ G OH * value of −1.105 eV, which is closer to the first-rank value than that of pure W 2 N (−0.59 1 eV). − The calculation results show that Ni doping of W 2 N can reduce the H binding energy as well as enhance the binding energy of OH and show better adsorption energy of hydrogen and hydroxide, which contributes to the excellent HER activity. − …”

Electrocatalytic Hydrogen Oxidation in Alkaline Media: From Mechanistic Insights to Catalyst Design

“…The specific activity of CeO 2 (r)-Ni/C was as high as 0.038 mA cm –2 , significantly higher than that of the contrast sample lacking oxygen vacancies. In addition to the above-mentioned combinations, other heterostructural catalysts have also demonstrated synergistic effects for HOR, such as MoO 2 /Ni@NF, SnO 2 /CeO 2 /ZSM, Rh/Rh 2 O 3 , Pd/SnO 2 , and Pd/Ni­(OH) 2 …”

Constructing a bifunctional MoO2/Co heterojunction for efficient electrocatalytic hydrogen evolution and hydrazine oxidation

“…[1][2][3] As a clean, non-polluting, renewable, and high-burning value secondary energy source, hydrogen has a wide range of sources and various uses, which makes it very suitable for replacing traditional fossil energy. [4][5][6][7][8] Among the variety of hydrogen production methods, electrochemical water splitting has attracted great attention due to its ease of operation, low cost, zero carbon emission and high hydrogen purity. [9][10][11][12][13] The process consists of two half reactions, namely the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), located at the cathode and anode of the cell, respectively.…”