Manipulation of Mott−Schottky Ni/CeO₂ Heterojunctions into N‐Doped Carbon Nanofibers for High‐Efficiency Electrochemical Water Splitting

Abstract

Designing affordable and efficient bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has remained a long‐lasting target for the progressing hydrogen economy. Utilization of metal/semiconductor interface effect has been lately established as a viable implementation to realize the favorable electrocatalytic performance due to the built‐in electric field. Herein, a typical Mott–Schottky electrocatalyst by immobilizing Ni/CeO2 hetero‐nanoparticles onto N‐doped carbon nanofibers (abbreviated as Ni/CeO2@N‐CNFs hereafter) has been developed via a feasible electrospinning‐carbonization tactic. Experimental findings and theoretic calculations substantiate that the elaborated constructed Ni/CeO2 heterojunction effectively triggers the self‐driven charge transfer on heterointerfaces, leading to the promoted charge transfer rate, the optimized chemisorption energies for reaction intermediates and ultimately the expedited reaction kinetics. Therefore, the well‐designed Ni/CeO2@N‐CNFs deliver superior HER and OER catalytic activities with overpotentials of 100 and 230 mV at 10 mA cm‐2, respectively, in alkaline solution. Furthermore, the Ni/CeO2@N‐CNFs‐equipped electrolyzer also exhibits a low cell voltage of 1.56 V to attain 10 mA cm‐2 and impressive long‐term durability over 55 h. The innovative manipulation of electronic modulation via Mott–Schottky establishment may inspire the future development of economical electrocatalysts for diverse sustainable energy systems.

Construction of Core–Shell CoMoO4@γ-FeOOH Nanosheets for Efficient Oxygen Evolution Reaction

“…Similar to what was mentioned previously, the HRTEM image and corresponding Fast Fourier transform pattern (FFT) in Figure 3f,h indicate the {112} planes where the lattice spacing is 3.5 Å and the {200} planes where the lattice spacing is 4.4 Å for CoMoO 4 observed along the [021] axis, as can be indexed from the combination of Figure 3g and its simulated corresponding FFT (Figure 3i). Previous reports have demonstrated that the electronic structure of an active site is highly related to the catalytic activity and could be adequately modulated by constructing heterostructures [30,31]. Hence, X-ray photoelectron spectroscopy (XPS) was employed to study detailed atomic and electronic structural information.…”

Ru-doping induced lattice strain in hetero-phase Ni2P–Ni12P5arrays enables simultaneous efficient energy-saving hydrogen generation and formate electrosynthesis

“…3e shows the XPS spectrum of C 1s with three diffraction peaks at 288.8 eV, 286.4 eV, and 284.6 eV belonging to C]O, C-N, and C-C, respectively. 41 In Fig. 3f, the XPS spectrum of N 1s proves the presence of pyrrole N at 400.4 eV and pyridine N at 399.5 eV.…”

Amorphous–crystalline FeNi2S4@NiFe–LDH nanograsses with molten salt as an industrially promising electrocatalyst for oxygen evolution

“…S8, † FeNi 2 S 4 @NiFe-LDH exhibits the highest peak intensity at≈g = 2.003, indicating the highest concentration of oxygen vacancies in FeNi 2 S 4 @NiFe-LDH. 47 These defect sites (oxygen vacancies) could lower the barrier for OH − anion adsorption, which is advantageous for increasing OER activity. 48 The OER electrocatalytic performances of the synthesized catalysts were analyzed using a three-electrode system in 1 M KOH.…”