Tungsten Carbide Hollow Microspheres with Robust and Stable Electrocatalytic Activity toward Hydrogen Evolution Reaction

Abstract

Here, we report a stable tungsten carbide hollow microsphere (W 2 C-HS) electrocatalyst with robust electrocatalytic activity toward hydrogen evolution reaction fabricated from carburization of tungsten oxides at 700 °C with CH 4 /H 2 flow, which demands overpotentials of 153 and 264 mV to deliver 10 and 100 mA cm –2 ascribing to the hollow structures beneficial for interfacial charge transfer as well as releasing of hydrogen molecular. Meanwhile, the W 2 C-HS electrocatalyst exhibits undetectable degradation after 20 000 potential cycles indicative of extraordinary durability; in contrast, overpotential@100 mA cm –2 is dramatically increased from 128 to 251 mV after only 2000 potential cycles for benchmark platinum electrocatalyst.

Hybrid Design Using Carbon Nanotubes Decorated with Mo2C and W2C Nanoparticles for Supercapacitors and Hydrogen Evolution Reactions

“…The shallow Tafel slope observed for Mo 2 C@CNT in both media further demonstrated the superior electrocatalytic activity. Moreover, the observed values are akin to the previously reported values, as shown in Figure f. ,− The established HER mechanisms in acidic and alkaline electrolytes are explained by eqs – below. ,, In the acidic medium, the HER process involves the ensuing three stages …”

“…By contrast, the bare CNT requires 282 and 242 mV to reach η 10 in the acidic and basic media, respectively. The bar chart in Figure c indicates that the HER results obtained for the Mo 2 C@CNT hybrid are considerably superior to those of various previously reported TMD- and TMC-based catalysts. ,− The high catalytic activity achieved by hybrid structures is mainly attributed to the exposed edges of the vertically aligned X 2 C nanosheets and the large area of the surface delivered by the CNT for interaction with the electrolyte, thus facilitating the rapid electron transfer needed to achieve high HER properties.…”

“…Here, Mo 2 C@CNT exhibits the highest J 0 values compared with those of the W 2 C@CNT and CNTs in acidic and alkaline media, thus demonstrating the high intrinsic HER behavior. In addition, the bar chart in Figure g indicates that Mo 2 C/W 2 C displays higher J 0 values and, hence, greater intrinsic activity than various previously reported hybrid-based electrocatalysts. ,− It is clearly evident that the strong attachment of the nanoparticles to the highly conductive CNTs in the Mo 2 C@W 2 C hybrid guarantees the high conductivity, assists the electron/ion transfer from the CNTs to the Mo 2 C@W 2 C, and provides plentiful catalytic reactive sites for the HER process.…”

Development and Mechanical Characterization of HGMS–EHS-Reinforced Hollow Glass Bead Composites

“…The solid buoyancy material is a low-density, high-strength, seawater-resistant composite foam material. It is mainly used to provide net buoyancy for various underwater operating systems, ensuring that its counterweight equipment can work stably and safely under water. , At the same time, it also has the advantages of low water absorption, good weather resistance, resistance to hydrostatic pressure, and large safety and reliability. It can be applied to the buoy system, marine mining system, deep sea carrying operation equipment, marine survey and monitoring system, offshore oil system, and so forth. − The syntactic foam buoyancy material forming process can be further subdivided into the casting method, the vacuum impregnation method, the liquid-transfer molding method, the particle deposition method, and the molding method .…”

W2N/WC composite nanofibers as an efficient electrocatalyst for photoelectrochemical hydrogen evolution

“…[8][9][10][11][12][13] Among the earth-abundant and inexpensive catalysts, tungstenbased catalysts, such as carbides and nitrides, have gained considerable interest for HER because of their unique properties, such as Pt-like electronic structure, good electrical conductivity and chemical inertness in acidic and basic solutions. [14][15][16] Especially, due to the narrow band gap of 2.2 eV, W 2 N was usually used as a potential photocatalyst for photoelectrochemical hydrogen production. 17 Moreover, it has been theoretically and experimentally displayed that tungsten nitride/tungsten carbide (W 2 N/WC) heterostructure catalyst exhibits outstanding synergistic enhancement in HER activity, which is much better than their individual material.…”