W‐Doped MoO₂/MoC Hybrids Encapsulated by P‐Doped Carbon Shells for Enhanced Electrocatalytic Hydrogen Evolution

Abstract

Ultrasonic spray pyrolysis (USP), as an industrially‐scalable synthetic technique used to prepare mesoporous products, has rarely been developed for accessing porous metal carbide hybrids for electrochemical hydrogen evolution reaction (HER). Herein, we report a mesoporous hybrid consisting of tungsten (W)‐doped molybdenum oxide/molybdenum carbide (MoO2/MoC) nanoparticles encapsulated by phosphorus (P)‐doped carbon shells (W‐MoO2/MoC@PC) as an efficient electrocatalyst using this technique. The utilization of SiO2 as a hard template endows W‐MoO2/MoC@PC with a mesoporous structure, and the effective W‐doping further enhances the HER electrocatalytic performance of W‐MoO2/MoC@PC catalyst. As expected, W‐MoO2/MoC@PC shows a low overpotential (η20=208 mV in 0.5 m H2SO4 and 209 mV in 1.0 m KOH for reaching a current density of 20 mA cm−2), and good stability in both acidic and basic electrolyte, which is a promising noble‐metal‐free HER catalyst. Moreover, this facile synthesis strategy is also suitable for preparing other metal‐doped Mo‐based nanocomposites, which can be used in the fields of electrocatalytic water splitting and energy conversion.

Fe‐doped CoNi0.5P Hierarchical Arrays as Efficient Bifunctional Electrocatalysts for Overall Water Splitting: Evolution of Morphology and Coordination of Catalytic Performance

“…However, the sluggish kinetics of the OER and HER seriously restrict the development of water electrolysis. The major obstacle which hampers the widely commercial application of water splitting is still lie in lacking of high‐efficient and durable bifunctional catalysts for both OER and HER . At present, precious metal‐based electrocatalysts including Pt (Pt/C or Pt alloys) and Ir/Ru oxides are considered to be the most active and efficient catalysts for HER and OER, but the scarcity and high cost greatly limited their practical application .…”

Ultrafine Dual‐Phased Carbide Nanocrystals Confined in Porous Nitrogen‐Doped Carbon Dodecahedrons for Efficient Hydrogen Evolution Reaction

“…The exchange current density is determined to be 0.15 mA cm −2 by fitting the linear portion of the Tafel plot at low current density (Figure S13b, Supporting Information). The highest value also indicates the best intrinsic electrocatalytic activity of MoC‐Mo 2 C/PNCDs . The smallest charge transfer resistance ( R ct ) during the HER process (Figure S14, Supporting Information) also suggests the most efficient HER kinetics .…”

Two‐Dimensional Nanosheet Structure of Co, S Co‐Doped Carbon‐Framework Supported MoO2 for Hydrogen Evolution Reaction in Alkaline Solutions

“…From the above analyses, the Co, S/MoO 2 −C exhibits promising HER performance compared to the early reports, such as MoO 2 nanowire, porous MoO 2 and nanoflower‐like MoO 2 etc. . The origins of the excellent electrochemical performance of Co, S/MoO 2 −C can be explained by the following aspects: (1) The carbon‐framework increases the dispersibility of Co, S/MoO 2 −C.…”

“…The capacitive arc can represent the resistance quantificationally. In Figure 3e such as MoO nanowire, porous MoO 2 and nanoflower-like MoO etc.. [4,5,[24][25][26][27][28] The origins of the excellent electrochemical performance of Co, S/MoO 2 À C can be explained by the following aspects: (1) The carbon-framework increases the dispersibility of Co, S/MoO 2 À C. Carbon-framework is a kind of three-dimensional self-supporting material which is obtained by MOF with rhombic dodecahedron and good dispersibility. Therefore, the carbon-framework can provide more space for the dispersion of MoO 2 , which results in MoO 2 owns a large specific surface area and plenty of exposed active sites for HER.…”