Super‐Hybrid Transition Metal Sulfide Nanoarrays of Co₃S₄ Nanosheet/P‐Doped WS₂ Nanosheet/Co₉S₈ Nanoparticle with Pt‐Like Activities for Robust All‐pH Hydrogen Evolution

Abstract

requires 58, 70, and 129 mV in alkaline, acid, and neutral media, respectively, to reach 10 mA cm -2 , which also presents fast reaction kinetics and high long-term stability. The experimental and density functional theory (DFT) results verify that the abundant active heterostructure in Super-Co 3 S 4 /P-WS 2 /Co 9 S 8 can not only provide Pt-like H*-adsorption Gibbs free energy (ΔG H* ) but also promote the H 2 O adsorption and dissociation kinetics for all-pH HER. Moreover, the collaboration of favorable metallic components and special nanoarray morphology can also strengthen the electric conductivity for electron transfer and promote the maximum exposure of active heterointerfaces for mass transport in electrocatalysis. The interesting strategy herein is expected to inspire the future design of advanced metal sulfide-based heterostructures for energy storage and conversion.

Dual CoxSy-Modified Tungsten Disulfide Double-Heterojunction Electrocatalyst for Efficient Hydrogen Evolution in All-pH Media

“…Moreover, in the XPS spectra of Co 2p for WS 2 /Co 9 S 8 /Co 4 S 3 (Figure g), Co 2p 3/2 and Co 2p 1/2 can be divided into four pairs of peaks, including Co 0 (at 779.3 and 793.6 eV), Co 3+ (at 781.6 and 796.9 eV), Co 2+ (at 783.5 and 799.7 eV), and sat. (at 786.9 and 803.8 eV). − The Co element in WS 2 /Co 9 S 8 /Co 4 S 3 exhibits multiple chemical valences, which verifies the formation of Co, Co 9 S 8 , and Co 4 S 3 . , Importantly, compared with Co 9 S 8 /Co 4 S 3 , the peaks of WS 2 /Co 9 S 8 /Co 4 S 3 belonging to Co 3+ and Co 2+ have same negative shifts of 0.3 eV, proving that more electrons are transferred from Co to W on the heterogeneous interface. , For W 4f of WS 2 /Co 9 S 8 /Co 4 S 3 (Figure h), the convolution peaks of WS 2 /Co 9 S 8 /Co 4 S 3 located at 32.7 and 34.7 eV belong to W 4+ 4f 7/2 and W 4+ 4f 5/2 , which have a positive shift (0.3 eV) compared with pure WS 2 . This also illustrates that W gets partial electrons from Co, revealing the strong coupling effect between W and Co.…”

“…47−50 The Co element in WS 2 /Co 9 S 8 /Co 4 S 3 exhibits multiple chemical valences, which verifies the formation of Co, Co 9 S 8 , and Co 4 S 3 . 43,51 Importantly, compared with Co 9 S 8 / Co 4 S 3 , the peaks of WS 2 /Co 9 S 8 /Co 4 S 3 belonging to Co 3+ and Co 2+ have same negative shifts of 0.3 eV, proving that more electrons are transferred from Co to W on the heterogeneous interface. 27,52 For W 4f of WS 2 /Co 9 S 8 /Co 4 S 3 (Figure 3h), the 4a.…”

Hollow cubic CdS@CoS/WS2dual S-scheme heterojunction superstructure toward optimized photothermal–photocatalytic performance

“…In addition, as CoS and WS 2 are loaded on the surface of CdS, the optical response range of CdS@CoS, CdS/WS 2 and CdS@CoS/WS 2 is markedly broadened to the infrared region and the optical absorption intensity is increased, indicating that the light absorption and utilization are improved. 31 To investigate the change of band gap energy when CdS, CoS and WS 2 are coupled, we investigate the UV-Vis spectrum in the Tauc equation which can estimate the optical band gap, obtained by the following formula:( αhv ) 2 = A ( hv − E g )where hv , α and A denote the photon energy, absorption coefficient and constant value of the semiconductor, respectively. The band gaps of different catalysts are calculated using the Kudelka–Munk equation.…”

Phosphorus vacancies improve the hydrogen evolution of MoP electrocatalysts

“…With increasing demand for hydrogen energy as a clean renewable energy, hydrogen production plays a key role in the whole of hydrogen energy utilization. [1][2][3] To date, there are numerous ways to obtain hydrogen, such as through biomass, natural gas and water. [4][5][6][7][8] Thereinto, the generation of hydrogen by electrochemically splitting water using renewable electricity is a clean and renewable process.…”