The fabrication of Co:ZnS/CoS2 heterostructure nanowires with a superior hydrogen evolution performance

2019 ◽  
Vol 3 (10) ◽  
pp. 2771-2778 ◽  
Author(s):  
Shancheng Yan ◽  
Ka Wang ◽  
Qingxia Wu ◽  
Fei Zhou ◽  
Zixia Lin ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Current Density ◽  
High Hydrogen ◽  
Tafel Slope ◽  
One Step ◽  
A Current

The ultrafine Co:ZnS/CoS2 heterostructure nanowires with high hydrogen evolution performance by one-step hydrothermal method. The overpotential required to reach a current density of 10 mAcm−2 was only 78 mV in 0.5 M H2SO4 solution, and the Tafel slope was 56 mV dec−1.

Construction of a hierarchical NiFe layered double hydroxide with a 3D mesoporous structure as an advanced electrocatalyst for water oxidation

2018 ◽  
Vol 5 (8) ◽  
pp. 1795-1799 ◽  
Author(s):  
Jiahao Yu ◽  
Fulin Yang ◽  
Gongzhen Cheng ◽  
Wei Luo
Keyword(s):  
Hydrothermal Method ◽  
Layered Double Hydroxide ◽  
Current Density ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Cost Effective ◽  
Mesoporous Structure ◽  
One Step ◽  
Double Hydroxide ◽  
A Current

A facile and cost-effective one-step hydrothermal method is used to synthesize NiFe LDH microclusters with a 3D hierarchically mesoporous architecture. This superior electrocatalyst can achieve a current density of 10 mA cm−2 with an ultralow overpotential of 211 mV toward the oxygen evolution reaction.

scholarly journals The facile one-step hydrothermal method to prepare MnO2 nanoparticles: Structural and electrochemical properties

2021 ◽  
Vol 2145 (1) ◽  
pp. 012034
Author(s):  
K Tangphanit ◽  
N Boonraksa ◽  
S Maensiri ◽  
E Swatsitang ◽  
K Wongsaprom
Keyword(s):  
Hydrothermal Method ◽  
Current Density ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Spherical Particles ◽  
Average Particle ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
One Step ◽  
A Current

Abstract MnO2 nanoparticles were successfully prepared via one-step hydrothermal method. The surface are properties of the MnO2 nanoparticles were determined by BET nitrogen adsorption-desorption measurement. The XRD analyses confirm the pure phase of γ-MnO2 and α-MnO2, having orthorhombic crystal structure (JCPDS file no.14-0644 and 44-0141). FE-SEM analysis reveals the combination of massively small spherical particles with average particle size 54.8 nm. The electrochemical results revealed that the MnO2 nanoparticles delivered the specific capacitance of 200.83 F/g at a current density of 1A/g. The cycle stability was usability 30% after 500 cycles at a current density of 5 A/g. The MnO2 nanoparticles reveal a energy density of 3.62 Wh/kg under a power density of 43.11 W/kg.

Effects of Electrodeposition Time on Ni/rGO Composite Electrode as an Efficient Catalyst for Hydrogen Evolution Reaction in Alkaline Media

2018 ◽  
Vol 15 (2) ◽  
pp. 178-187
Author(s):  
Lixin Wang ◽  
Peipei Zhang ◽  
Lei Bai ◽  
Lei Cao ◽  
Jing Du ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Charge Transfer Resistance ◽  
Composite Electrodes ◽  
Transfer Resistance ◽  
Tafel Slope ◽  
Electrodeposition Time ◽  
A Current

Background: Ni/rGO composite electrode has been fabricated by facile supergravity electrodeposition as a low-cost catalyst for efficient hydrogen evolution in alkaline media. In this paper, the electrodeposition time is the main research variable. When the electrodeposition time is 100 minutes, the Ni/rGO-100 catalyst manifests the highest electrocatalytic activity toward the hydrogen evolution reaction (HER). In 1.0 M NaOH solution, the overpotential at a current density of 100 mA cm-2, Tafel slope and charge transfer resistance of Ni/rGO-100 catalyst is 184 mV, 77 mV dec-1 and 4.173 Ω, respectively. In addition, Ni/rGO-100 catalyst shows a long-term durability at a constant current density of 100 mA cm-2 for 10 h. The outstanding HER electrocatalytic performance of the Ni/rGO-100 is mainly related to the synergetic combination of Ni and rGO, as well as the enlarged exposure of catalytically active sites and improved transport of electrons arising from the good conductivity of graphene. Method: In a classic experiment, GO was prepared by modified Hummers method. The Ni/rGO composite electrodes were prepared by supergravity electrodeposition, which has been reported in detail in our published paper. Firstly, a ø10 cm × 2 cm Ni foam circle was cleaned sequentially in HCl solution (15%), acetone and DI water for 5 min with ultrasonication to be used as a cathode. And a pure nickel pipe was used as anode. The Ni/rGO composite cathodes were electrodeposited in a blackish green plating bath which contained 350 g L-1 Ni(NH2SO3)2·6H2O, 10g L-1 NiCl2·6H2O, 30 g L-1 NH4Cl , 1.0 g L-1 GO colloidal solution with different electrodeposition time, 10min, 30min, 60min, 80min, 100min, respectively. The pH value of the plating bath is 3.5-3.8. The above five electrodes were respectively denominated as Ni/rGO-10, Ni/rGO-30, Ni/rGO-60, Ni/rGO-80, Ni/rGO-100. All composite electrodes were performed under the strength of the supergravity with G=350 g at a current density of 3 A dm-2 at 318 K. Afterwards the Ni foam coated with Ni/rGO hybrid was taken out of the reaction vessel, followed by washing with deionized water to remove physical adsorption residua, and then dried at 80°C. Results: In this paper, the electrodeposition time is the main research variable. When the electrodeposition time is 100 minutes, the Ni/rGO-100 catalyst manifests the highest electrocatalytic activity toward the hydrogen evolution reaction (HER). In 1.0 M NaOH solution, the overpotential at a current density of 100 mA cm-2, Tafel slope and charge transfer resistance of Ni/rGO-100 catalyst is 184 mV, 77 mV dec-1 and 4.173 Ω, respectively. In summary, we have synthesized a class of composite electrodes (Ni/rGO) for HER in alkaline solution by electrodeposition under supergravity field. We studied the effect of electrodeposition time on electrode performance in detail. With the increase of electrodeposition time, the number of active sites is enlarged provided by the electrode. When the electrodeposition time is 100 min, we fabricate the best electrode (Ni/rGO-100). The η100, Tafel slope and charge transfer resistance of Ni/rGO-100 is 184 mV, 77 mV dec-1 and 4.173 Ω, respectively. The introduction of graphene and supergravity field plays a key role in improving the performance of the electrodes. This work is a pivotal part of the development of Ni/rGO as a non-precious HER catalyst for green energy field.

Pt-like catalytic behavior of MoNi decorated CoMoO3 cuboid arrays for the hydrogen evolution reaction

2018 ◽  
Vol 6 (32) ◽  
pp. 15558-15563 ◽  
Author(s):  
Dewen Wang ◽  
Ce Han ◽  
Zhicai Xing ◽  
Qun Li ◽  
Xiurong Yang
Keyword(s):  
Synergistic Effect ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
High Hydrogen ◽  
Catalytic Behavior ◽  
Unique Structure ◽  
Low Overpotential ◽  
A Current

Owing to the unique structure and synergistic effect between MoNi and CoMoO3, the MoNi/CoMoO3/NF exhibits high hydrogen evolution activity which requires a low overpotential of only 18 mV to deliver a current density of 10 mA cm−2.

Improving hydrogen evolution performance of Co:FeS2/CoS2 nano-heterostructure at elevated temperatures

2019 ◽  
Vol 9 (7) ◽  
pp. 786-791
Author(s):  
Ka Wang ◽  
Haizeng Song ◽  
Zixia Lin ◽  
Yuan Gao ◽  
Han Wu ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Precious Metal ◽  
Elevated Temperatures ◽  
Clean Energy ◽  
Tafel Slope ◽  
High Efficient ◽  
Earth Abundant ◽  
One Step

Fabrication and improvement of high-efficient, durable, and earth-abundant non-precious metal hydrogen evolution electrocatalysts are particularly important in the production of clean energy hydrogen. In this study, we synthesized Co:FeS2/CoS2 nano-heterostructure with superior hydrogen evolution performance by a typical one-step hydrothermal method. When the temperature of HER solution was raised from 0 °C to 60 °C, the overpotential for Co:FeS2/CoS2 nano-heterostructure at 10 cm–2 was reduced from 115 to 75 mV and its Tafel slope did not change significantly. Moreover, the overpotential for Co:FeS2/CoS2 nano-heterostructure increased by only 6 mV after 1000 cycles of CV at 60 °C. This work provides a strategy for preparing and improving the performance of non-precious metal electrocatalysts to replace precious metal electrocatalysts.

A highly stable CoMo2S4/Ni3S2 heterojunction electrocatalyst for efficient hydrogen evolution

2021 ◽  
Author(s):  
Minmin Wang ◽  
Mengke Zhang ◽  
Wenwu Song ◽  
Weiting Zhong ◽  
Xunyue Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Current Density ◽  
A Current

A CoMo2S4/Ni3S2 heterojunction is prepared with an overpotential of only 51 mV to drive a current density of 10 mA cm−2 in 1 M KOH solution and ∼100% of the potential remains in the ∼50 h chronopotentiometric curve at 10 mA cm−2.

scholarly journals Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1040 ◽  
Author(s):  
Getachew Solomon ◽  
Raffaello Mazzaro ◽  
Vittorio Morandi ◽  
Isabella Concina ◽  
Alberto Vomiero
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Crystal Morphology ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Mos2 Nanosheets ◽  
Microwave Assisted

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.

Bimetallic ZnCo nanorod array for highly reactive and durable hydrogen evolution reaction

2022 ◽  
Author(s):  
Jianmin Zhu ◽  
Lishuang Xu ◽  
Shuai Zhang ◽  
Ying Yang ◽  
Licheng Huang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Nickel Foam ◽  
Nanorod Array ◽  
One Step ◽  
Array Structure

One-step hydrothermal method to synthesize a stable ZnCo2(OH)F nanorod array structure supported by nickel foam.

CO2 electrolysis to multicarbon products in strong acid

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1074-1078
Author(s):  
Jianan Erick Huang ◽  
Fengwang Li ◽  
Adnan Ozden ◽  
Armin Sedighian Rasouli ◽  
F. Pelayo García de Arquer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Evolution ◽  
Current Density ◽  
Carbon Emissions ◽  
Active Sites ◽  
Cell Voltage ◽  
Strong Acid ◽  
Electrochemically Active ◽  
Co2 Electrolysis ◽  
A Current

Carbon dioxide electroreduction (CO2R) is being actively studied as a promising route to convert carbon emissions to valuable chemicals and fuels. However, the fraction of input CO2 that is productively reduced has typically been very low, <2% for multicarbon products; the balance reacts with hydroxide to form carbonate in both alkaline and neutral reactors. Acidic electrolytes would overcome this limitation, but hydrogen evolution has hitherto dominated under those conditions. We report that concentrating potassium cations in the vicinity of electrochemically active sites accelerates CO2 activation to enable efficient CO2R in acid. We achieve CO2R on copper at pH <1 with a single-pass CO2 utilization of 77%, including a conversion efficiency of 50% toward multicarbon products (ethylene, ethanol, and 1-propanol) at a current density of 1.2 amperes per square centimeter and a full-cell voltage of 4.2 volts.

One-step solvothermal fabrication of Cu@PANI core–shell nanospheres for hydrogen evolution

Nanoscale ◽  
2018 ◽  
Vol 10 (46) ◽  
pp. 22055-22064 ◽  
Author(s):  
Ting Wang ◽  
Dan Wu ◽  
Youliang Wang ◽  
Tingbo Huang ◽  
Gary Histand ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Light Absorption ◽  
Good Stability ◽  
Core Shell ◽  
Electron Hole ◽  
Facile Hydrothermal Method ◽  
Strong Light ◽  
Efficient Separation ◽  
One Step

Cu@PANI core–shell nanospheres synthesized by a facile hydrothermal method exhibit strong light absorption, good stability and efficient separation of photo-generated electron–hole pairs.

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