Highly porous Ag-Ag 2 S/MoS 2 with additional active sites synthesized by chemical etching method for enhanced electrocatalytic hydrogen evolution

2014 ◽  
Vol 142 ◽  
pp. 173-181 ◽  
Author(s):  
Xiaohong Xia ◽  
Xiaojuan Zhao ◽  
Weichun Ye ◽  
Chunming Wang
Keyword(s):  
Hydrogen Evolution ◽  
Chemical Etching ◽  
Active Sites ◽  
Etching Method ◽  
Highly Porous

Chemical etching manipulated local electronic structure upheaval of graphdiyne for efficient hydrogen evolution

2D Materials ◽  
2021 ◽  
Author(s):  
Kaikai Ma ◽  
Yunqi Zhao ◽  
Qingliang Liao ◽  
Zhaozhao Xiong ◽  
Xinting Li ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Chemical Etching ◽  
Active Sites ◽  
Theoretical Calculations ◽  
Great Expectation ◽  
Local Electronic Structure ◽  
A Current ◽  
Carbon Based

Abstract Graphdiyne (GDY), featured with unique sp2, sp-hybridized form and inherent inhomogeneous electron distribution, retains great expectation to be developed into highly efficient electrocatalysts for hydrogen evolution reaction (HER). However, the state-of-the-art GDY-based electrocatalysts still suffer from weak catalytic activity and sluggish reaction kinetics originating from the severe scarcity of in-plane active sites and insufficient electrical conductivity. Targeted at this bottleneck issue, electronic structure regulation, recognized as an extremely precise technical route, is promising to improve HER performances of carbon-based electrocatalysts. Herein, a facile controllable chemical etching strategy is well leveraged to introduce sp2-hybridized carbon-oxygen bonds (Csp2-O) into GDY for precise manipulation both of its electronic and spatial structures. Experimental results and theoretical calculations coherently manifest that Csp2-O introduction into GDY can not only induce its electronic structure upheaval to strengthen surface electron transport capability, but also trigger intensive carbon-oxygen p-p orbital hybridization to enhance the catalytic activity of acetylenic bond sites. As a result, the optimal GDY sample after etching delivers excellent HER performance with an overpotential of only 101 mV at a current density of 10 mA cm-2 and a low Tafel slope of 54 mV dec-1, which surpasses most of reported metal-free based electrocatalysts. This work provides a universal route for precise modulation of inherent electronic structure in GDY, and can be further extended to boost the overall performances of other carbon-based catalysts

Ru single atoms and nanoclusters on highly porous N–doped carbon as hydrogen evolution catalyst in alkaline solutions with ultrahigh mass activity and turnover frequency

2021 ◽  
Author(s):  
Yijun Li ◽  
Huijing Liu ◽  
Bing Li ◽  
Zhenzhen Yang ◽  
Zhenguo Guo ◽  
...  
Keyword(s):  
Energy Source ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Active Sites ◽  
Sustainable Energy ◽  
Alkaline Solutions ◽  
Turnover Frequency ◽  
Single Atoms ◽  
Mass Activity ◽  
Highly Porous

Electrocatalytic water splitting is one of the most desirable ways to provide hydrogen which is a clean and sustainable energy source. Improving the formation and the exposure of active sites...

Nitrogen and fluorine dual-doped porous graphene-nanosheets as efficient metal-free electrocatalysts for hydrogen-evolution in acidic media

2017 ◽  
Vol 7 (11) ◽  
pp. 2228-2235 ◽  
Author(s):  
Xin Yue ◽  
Shangli Huang ◽  
Yanshuo Jin ◽  
Pei Kang Shen
Keyword(s):  
Hydrogen Evolution ◽  
Chemical Etching ◽  
Graphene Nanosheets ◽  
Ion Adsorption ◽  
Acidic Media ◽  
Metal Free ◽  
Porous Graphene ◽  
Etching Method ◽  
Pyridinic N

Nitrogen and fluorine dual-doped porous graphene-nanosheets (NFPGNS) with pyridinic N doped rich configurations have been synthesized by a simple ion adsorption and chemical-etching method.

Field Effect Modulation of Electrocatalytic Hydrogen Evolution at Back-Gated Two-Dimensional MoS2 Electrodes

2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie
Keyword(s):  
Electric Field ◽  
Hydrogen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Electrode Materials ◽  
Density Functional Theory Calculations ◽  
Electronic Charge ◽  
Back Side ◽  
Gate Electrode ◽  
Conventional Manner

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>

Boron-modulated surface of hollow nickel framework for improved hydrogen evolution

2021 ◽  
Author(s):  
Weishi Gu ◽  
Zhongqin Pan ◽  
Han Tao ◽  
Yanling Guo ◽  
Jun Pu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Active Sites ◽  
Nano Structure ◽  
Binder Free ◽  
Structure Engineering

Taking advantage of micro/nano structure engineering and surface boron modulation, we developed a binder-free and support-free electrode to enrich and optimize active sites of Ni.

Abundant Active Sites on the Basal Plane and Edges of Layered van der Waals Fe3GeTe2 for Highly Efficient Hydrogen Evolution

2021 ◽  
pp. 313-319
Author(s):  
Amir A. Rezaie ◽  
Eunsoo Lee ◽  
Diana Luong ◽  
Johan A. Yapo ◽  
Boniface P. T. Fokwa
Keyword(s):  
Hydrogen Evolution ◽  
Basal Plane ◽  
Active Sites ◽  
Van Der Waals ◽  
Highly Efficient

scholarly journals Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Reduced Graphene ◽  
Heterogeneous Interfaces ◽  
Wide Ph Range ◽  
Ph Range ◽  
A Current ◽  
Poor Stability

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

An efficient CoS2/CoSe2 hybrid catalyst for electrocatalytic hydrogen evolution

2017 ◽  
Vol 5 (6) ◽  
pp. 2504-2507 ◽  
Author(s):  
Yaxiao Guo ◽  
Changshuai Shang ◽  
Erkang Wang
Keyword(s):  
Hydrogen Evolution ◽  
Electrocatalytic Activity ◽  
Active Sites ◽  
High Dispersion ◽  
Hybrid Catalyst

The CoS2/CoSe2 hybrid catalyst exhibits superior HER electrocatalytic activity as well as excellent electrochemical durability. CoSe2/DETA nanobelts not only afford an interconnected conducting network, but also demonstrate superior HER electrocatalytic activity. High dispersion and smaller CoS2 nanoparticles on the surface can provide abundant active sites for the HER.

scholarly journals Engineering single-atomic ruthenium catalytic sites on defective nickel-iron layered double hydroxide for overall water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Layered Double Hydroxide ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Rational Design ◽  
Single Atom ◽  
Nickel Iron ◽  
Double Hydroxide

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.

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