Photoassisted Electrochemical Hydrogen Evolution Reaction of MFe₂O₄@Ultrathin Black Phosphorus Amorphous–Crystalline Interface

Abstract

Exploring highly active, stable, and low-cost catalysts for photoelectrochemical hydrogen evolution reaction (PE-HER) is vital in the field of energy conversion. Herein, we construct a new amorphous crystalline interface that amorphous iron-based spinel oxide (A-MFe 2 O 4 (M = Ni, Co, Zn)) is uniformly anchored on the crystalline exfoliated black phosphorus (C-EBP) nanosheets via electrochemical and solvothermal strategies. Among these A-MFe 2 O 4 @C-EBP catalysts, more oxygen defects of A-NiFe 2 O 4 @C-EBP interface provide a larger effective electrochemical active area of 32.33 mF cm −2 as well as a turnover frequency of 0.44 s −1 and allow for an optimum equilibrium of the hydrogen-containing adsorption intermediates. Furthermore, A-NiFe 2 O 4 @C-EBP exhibits significant PE-HER performance with an overpotential of 42 mV at 10 mA cm −2 under visible-light irradiation. Density functional theory (DFT) calculations show that the amorphous−crystalline composite structure causes a large number of oxygen defects enhancing the intrinsic activity of A-NiFe 2 O 4 @ C-EBP, which A-NiFe 2 O 4 @C-EBP significantly improves its adsorption capacity for H* for HER and has the lowest Gibbs free energy change for HER. This study not only provides a superior multifunctional amorphous−crystalline interface catalysts but also helps to understand the catalytic mechanism of PE-HER.

Sea urchin-like amorphous MgNiCo mixed metal hydroxide nanoarrays for efficient overall water splitting under industrial electrolytic conditions

“…Due to the different radii of Mg and Ni/Co, the substitution of Mg changes the bond angle and bond length of covalent bonds of NiCo-OH, leading to lattice distortion and causing the transformation of morphology. 1,2 In addition, the substitution of Mg changes the growth direction of NiCo-OH, leading to a slight shrink along the C-axis crystal plane and tending to grow along the A-axis crystal plane. 36,37 This may be the reason for the formation of nanowire structures.…”

“…As one of the ways to produce hydrogen, water splitting has numerous advantages, such as high purity, fast rate, and environmental friendliness. [1][2][3] During the water splitting process, the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) occur at the cathode and the anode, respectively. In comparison, the OER is unfavorable for thermodynamics and kinetics, which limits the application of overall water splitting.…”

Multicomponent 3d-Metal Nanoparticles in Amorphous Carbon Sponge for Electrocatalysis Water Splitting

“…To realize efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), great enthusiasm has been shown toward electrocatalysts incorporating nonexpensive 3d transition metals for their abundancy and versatile electronic structures . Heterometal doping, multicomponent synergism, heterojunctions, phase boundaries, disorders, and defects were found to be crucial to improve the electrocatalysis performance. − However, it is quite challenging to achieve molecular-level control in the preparation of hierarchical multicomponent nanostructures . Issues associated with competitive side reactions, unmatched thermodynamics, and diverse reaction kinetics are widely encountered in traditional synthesis methods such as solution coprecipitation, raw mixture pyrolysis, and mechanical milling.…”

AgNWs/Fe3O4@NC Conductive Network Hierarchical Assembly to Prepare Flexible EMI Shielding Textile

“…In actual EMI shielding application measurements, the composite film proved to be effective in blocking the transmission of electromagnetic waves. [40][41][42][43] Here, we synthesized a hollow-structured Fe 3 O 4 nanosphere and coated its surface with a N-doped carbon layer (Fe 3 O 4 @NC). This novel structure created many dipole centers and improved the EMI of Fe 3 O 4 @NC.…”

“…In actual EMI shielding application measurements, the composite film proved to be effective in blocking the transmission of electromagnetic waves. [ 40–43 ]…”