Engineering micro/nanostructures of Mo₂C/porous nanocarbon for enhanced hydrogen production

Abstract

As non-noble metal material, molybdenum carbide was considered to be one of the most potential electrocatalysts for hydrogen evolution reaction (HER) due to its similar electron structure to platinum. However,...

Phase Engineering of Molybdenum Carbide/Oxide for Highly‐Efficient Electrocatalytic Hydrogen Production

“…[41] In the results of measured electrochemical impedance of MOMC@C material (Figure 3e), R s represents the solution resistance, R p represents the surface porosity and R ct represents the charge transfer resistance, which can reflect the conductivity of the catalyst. [42] The R ct values of MOMC@C1, MOMC@C2, MOMC@C3 and MOMC@C6 are 400.0, 52.2, 77.9 and 137.8 Ω, respectively. Obviously, MOMC@C2 has small resistance and high conductivity.…”

“…The main reason is that pyridine and pyrrole nitrogen have the high affinity with transition metals such as Mo, resulting in significant synergistic effects at the interface and improve electrocatalytic performance [41] . In the results of measured electrochemical impedance of MOMC@C material (Figure 3e), R s represents the solution resistance, R p represents the surface porosity and R ct represents the charge transfer resistance, which can reflect the conductivity of the catalyst [42] . The R ct values of MOMC@C1, MOMC@C2, MOMC@C3 and MOMC@C6 are 400.0, 52.2, 77.9 and 137.8 Ω, respectively.…”

Effect of coordinated anions on ferromagnetically coupled Dy2 zero-field single-molecule magnets

“…The Schiff base formed by the condensation of hydrazide and aldehydes with phenolic groups is a good ligand commonly used to construct dysprosium(III) SMMs. 19,21,[43][44][45][46][47] Recently, we have used a Schiff base formed by the condensation of pyrimidine-4-carbohydrazide and 5-fluorosalicylaldehyde to construct (1) and Dy 2 L 2 (DMF) 2 (AcO) 2 (2), respectively, with different terminal coordinated anions: the nitrate anion in 1 and the acetate anion in 2. This provides an excellent opportunity to inspect the structures and SMM properties by altering the terminal coordinated anions with the same coordination mode.…”

“…On the other hand, a consistent magnetic axis orientation between the cations in an SMM composed of multiple lanthanide ions is not easy to obtain, so it is hard to achieve good SMM properties. 2, [15][16][17][18][19] The higher the number of lanthanide ions, the less likely it is to have the same axis orientation; therefore, the SMMs containing only two lanthanide(III) ions are attracting more and more attention. If a lanthanide(III) dinuclear SMM exhibits ferromagnetic interaction, the magnetic axis orientation of the two lanthanide(III) ions can be consistent, but this is a great challenging task; the reason is that the 4f electrons of different lanthanide(III) ions are not prone to magnetic exchange; even when the magnetic exchange occurs, it is usually a weak antiferromagnetic coupling.…”

“…) could be fitted with τ −1 = CT n + τ 0 −1 exp (−U eff /kT ), which contains the Orbach process and the Raman process, giving n = 3.69, C = 0.03403 s −1 K −3 , 69 U eff /k = 63.1 K and τ 0 = 7.2 × 10 −6 s. Like other zero-field Dy(III) SMMs,19,56 the U eff /k value becomes somewhat larger and the τ 0 value becomes somewhat smaller when a dc magnetic field is applied.The zero-field ac magnetic susceptibility of 2 has similarities with that of 1. As shown in Fig.4a, the frequency…”