Synergistic N-Doping and Heterointerface Engineering in W₂C/W Nanoarrays Enable pH-Universal Hydrogen Evolution Catalysis

Abstract

The electrocatalytic hydrogen evolution reaction (HER) by nonprecious metal-based cathodes provides a cost-effective way to store renewable energy as hydrogen fuel. However, pH variation on the cathode surface during electrolysis may lead to performance deterioration. Herein, the heterostructure electrode composed of nitrogen-doped ditungsten carbide/monolithic tungsten interface (N–W2C/W) is developed. The as-obtained electrode showed superior HER performance in pH-universal conditions, achieving −10 mA cm–2 with small overpotentials of 90, 90, and 82 mV in acidic, neutral, and alkaline electrolytes, respectively. Moreover, the electrocatalyst shows negligible performance decay after 24 h at the current densities of even −500 mA cm–2. Theoretical studies reveal that the interface W site exhibits suitable Gibbs free energy of hydrogen adsorption. Moreover, the unique interfacial structure provides synergistic active sites for water dissociation. This work provides an approach to design an interfacial structure based on nonprecious metals for highly efficient HER electrocatalysis.

Solar Energy Storage Using a Cu2O‐TiO2 Photocathode in a Lithium Battery

“…XRD diffractogram (Figure 1a) identifies the face-centered cubic Cu 2 O phase without detectable presence of CuO or Cu traces. [28] XPS spectrum (Figure S7, Supporting Information) confirms +1 as state of oxidation of copper. XPS also detects the presence of CuO due to minor surface oxidation of Cu 2 O.…”

“…The extrapolated value estimates a Tauc gap of 1.97 eV ± 0.02 eV (Figure 1b), value in good agreement with the literature. [28,30] UPS spectrum (Figure 1c) shows the position of the valenceband maximum with reference to the Fermi level of the instrument (VBMF), determined by the extrapolation of the steepest descent of the leading edge of the spectrum to the base line . [31] The estimated VBMF is 0.76 eV.…”

Tuning the visible colour of octahedral manganese(iii) phthalocyanines via axial ligand exchange

“…Driving their primary industrial use as pigments and dyes, metallophthalocyanines (PcM) are a class of tetradentate macrocyclic complexes with extremely high ε values in the UVvisible regions, as well as high chemical and thermal stability and a resistance to UV degradation. [1][2][3][4][5][6][7][8][9][10] With the ring having a rigid, planar structure, there are open axial sites on the metal that permit facile ligand exchange for many transition metals (e.g. M = Mn, Fe, Co, Zn).…”

Atomic-layered metal–organic framework on NiFe LDH for enhanced electrocatalytic oxygen evolution reaction

“…[4][5][6][7] Recently research efforts have been largely devoted to the development of highperformance OER electrocatalysts, such as noble-metal and their oxides, e.g. Ir/Ru and IrO 2 and RuO 2 , [8][9][10] but their wide application is limited by high cost. Up to now, much research efforts have been devoted to searching non-precious transition metal (Ni, Fe) based catalysts, including oxides/hydroxide, chalcogenide, nitride, and perovskites oxides.…”