scholarly journals Two-Dimensional Mn-Co LDH/Graphene Composite towards High-Performance Water Splitting

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 350 ◽  
Author(s):  
Jian Bao ◽  
Junfeng Xie ◽  
Fengcai Lei ◽  
Zhaolong Wang ◽  
Wenjun Liu ◽  
...  
Keyword(s):  
Water Splitting ◽  
High Performance ◽  
High Current Density ◽  
High Current ◽  
Hydrogen Electrode ◽  
Promising Candidate ◽  
New Material ◽  
Ultrathin Nanosheet ◽  
Double Hydroxides ◽  
First Time

The oxygen evolution reaction (OER) is a complex multi-step four-electron process showing sluggish kinetics. Layered double hydroxides (LDH) were reported as promising catalysts for the OER, but their low electrical conductivity restricts their widespread applications. To overcome this problem, a composite material containing Mn-Co LDH ultrathin nanosheet and highly conductive graphene was synthesized for the first time. Benefited from the high electrocatalytic activity and the superior charge transfer ability induced by these components, the new material shows superior OER activity. Used as the OER catalyst, a high current density of 461 mA cm−2 at 2.0 V vs. RHE (reversible hydrogen electrode) was measured besides shows a low overpotential of 0.33 V at 10 mA cm−2. Moreover, the new composite also shows a superior bifunctional water splitting performance as catalyst for the OER and HER (hydrogen evolution reaction) catalysts. Our results indicate that the presented material is a promising candidate for water splitting which is cheap and efficient.

scholarly journals High-performance and stable photoelectrochemical water splitting cell with organic-photoactive-layer-based photoanode

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Je Min Yu ◽  
Jungho Lee ◽  
Yoon Seo Kim ◽  
Jaejung Song ◽  
Jiyeon Oh ◽  
...  
Keyword(s):  
Water Splitting ◽  
Organic Semiconductors ◽  
High Performance ◽  
Energy Levels ◽  
Photocurrent Density ◽  
Hydrogen Electrode ◽  
Photoactive Layer ◽  
Onset Potential ◽  
The Stability ◽  
Double Hydroxides

Abstract Considering their superior charge-transfer characteristics, easy tenability of energy levels, and low production cost, organic semiconductors are ideal for photoelectrochemical (PEC) hydrogen production. However, organic-semiconductor-based photoelectrodes have not been extensively explored for PEC water-splitting because of their low stability in water. Herein, we report high-performance and stable organic-semiconductors photoanodes consisting of p-type polymers and n-type non-fullerene materials, which is passivated using nickel foils, GaIn eutectic, and layered double hydroxides as model materials. We achieve a photocurrent density of 15.1 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) with an onset potential of 0.55 V vs. RHE and a record high half-cell solar-to-hydrogen conversion efficiency of 4.33% under AM 1.5 G solar simulated light. After conducting the stability test at 1.3 V vs. RHE for 10 h, 90% of the initial photocurrent density are retained, whereas the photoactive layer without passivation lost its activity within a few minutes.

scholarly journals Stabilized Hydroxide-Mediated Nickel-Based Electrocatalysts for High-Current-Density Hydrogen Evolution in Alkaline Media

2021 ◽  
Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Current Density ◽  
Critical Energy ◽  
Alkaline Media ◽  
Scale Production ◽  
High Current ◽  
Large Scale Production ◽  
Electrochemical Water Splitting

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...

One-step Synthesis of Amorphous Nickel Iron Phosphide Hierarchical Nanostructures for Water Electrolysis with Superb Stability at High Current Density

2021 ◽  
Author(s):  
Yuefeng Yu ◽  
Xun He ◽  
Rong Li ◽  
Xinglong Gou
Keyword(s):  
High Performance ◽  
High Current Density ◽  
Water Electrolysis ◽  
Bifunctional Catalysts ◽  
High Current ◽  
Hierarchical Nanostructures ◽  
Iron Phosphide ◽  
Nickel Iron ◽  
Metal Free ◽  
One Step

Development of noble-metal-free high-performance bifunctional catalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is essential but challenging for hydrogen production from water electrolysis. Herein, amorphous bimetallic...

Uncovering the role of Ag in layer-alternating Ni3S2/Ag/Ni3S2 as an electrocatalyst with enhanced OER performance

2020 ◽  
Vol 7 (19) ◽  
pp. 3627-3635 ◽  
Author(s):  
Rui Guo ◽  
Yan He ◽  
Renchao Wang ◽  
Junhua You ◽  
Hongji Lin ◽  
...  
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
High Current Density ◽  
High Current

It is increasingly important to develop an efficient OER catalyst that can provide high current density at low overpotentials to improve water splitting efficiency.

Preparation and Characterization of CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA Bipolar Membrane Using Electrospinning Technique

2013 ◽  
Vol 774-776 ◽  
pp. 795-798
Author(s):  
Ting Jin Zhou ◽  
Min Lu ◽  
Ri Yao Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Splitting ◽  
Current Density ◽  
Voltage Drop ◽  
High Current Density ◽  
High Current ◽  
Bipolar Membrane ◽  
Electrospinning Technique ◽  
Exchange Layer

Carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA) and chitosan (CS)-polyvinyl alcohol were cross-linked by Fe3+and glutaraldehyde respectively to prepare cation exchange layer and anion exchange layer, and polyvinyl alcohol-sodium alginate (SA)-metal octocarboxyphthalocyanine (MePc (COOH)8, a kind of water splitting catalyst, here, Me stands for Fe3+or Co2+) nanofibers were prepared by electrospinning technique and introduced into the interlayer to obtain the CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA bipolar membrane (BPM). The experimental results showed that compared with the BPM without the PVA-SA-MePc (COOH)8interlayer, the water splitting efficiency at the interlayer of the CMC-PVA/PVA-SA-MePc (COOH)8/ CS-PVA BPM was obviously increased, and its membrane impedance decreased. When the concentration of FePc (COOH)8in the PVA-SA-FePc (COOH)8nanofibers was 3.0%, the trans-membrane voltage drop (IRdrop) of the CMC-PVA/PVA-SA-FePc (COOH)8/CS-PVA BPM was as low as 0.6V at a high current density of 90 mA/cm2.

An extremely low Pt loading cathode for a highly efficient proton exchange membrane water electrolyzer

Nanoscale ◽  
2017 ◽  
Vol 9 (48) ◽  
pp. 19045-19049 ◽  
Author(s):  
Hoyoung Kim ◽  
Seunghoe Choe ◽  
Hyanjoo Park ◽  
Jong Hyun Jang ◽  
Sang Hyun Ahn ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Current Density ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
High Current Density ◽  
Proton Exchange ◽  
The Self ◽  
High Current ◽  
Low Pt Loading ◽  
Exchange Membrane

The self-terminated electrodeposition (SED) of a Pt cathode with enhanced mass transfer demonstrates high performance of PEMWEs at high current density.

scholarly journals N-Doped Carbon Boosted the Formation of Few-Layered MoS2 for High-Performance Lithium and Sodium Storage

2021 ◽  
Vol 8 ◽  
Author(s):  
Junfeng Li ◽  
Xianzi Zhou ◽  
Kai Lu ◽  
Chao Ma ◽  
Liang Li ◽  
...  
Keyword(s):  
Current Density ◽  
High Performance ◽  
High Current Density ◽  
Low Cost ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Molybdenum Sulfide ◽  
High Current ◽  
High Theoretical Capacity ◽  
Sodium Storage

Molybdenum sulfide (MoS2) has become a potential anode of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its high theoretical capacity and low cost. However, the volume expansion, poor electrical conductivity and dissolution of polysulfides in the electrolyte during the cycling process severely limited its applications. Herein, few-layered MoS2@N-doped carbon (F-MoS2@NC) was synthesized through a facile solvothermal and annealing process. It was found that the addition of N-doped carbon precursor could significantly promote the formation of few-layered MoS2 and improve the performances of lithium and sodium storage. A high reversible capacity of 482.6 mA h g−1 at a high current density of 2000 mA g−1 could be obtained for LIBs. When used as anode material for SIBs, F-MoS2@NC hybrids could maintain a reversible capacity of 171 mA h g−1 at a high current density of 1,000 mA g−1 after 600 cycles. This work should provide new insights into carbon hybrid anode materials for both LIBs and SIBs.

scholarly journals Hierarchical Porous Carbon Derived from Sichuan Pepper for High-Performance Symmetric Supercapacitor with Decent Rate Capability and Cycling Stability

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 553 ◽  
Author(s):  
Hengshuo Zhang ◽  
Wei Xiao ◽  
Wenjie Zhou ◽  
Shanyong Chen ◽  
Yanhua Zhang
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
High Current Density ◽  
Rate Capability ◽  
Cycling Stability ◽  
Koh Activation ◽  
High Current ◽  
Symmetric Supercapacitor ◽  
Hierarchical Porous

Hierarchical micro-mesoporous carbon (denoted as HPC-2 in this study) was synthesized by pre-carbonization of biomass Sichuan pepper followed by KOH activation. It possessed well-developed porosity with the specific surface area of 1823.1 m2 g−1 and pore volume of 0.906 cm3 g−1, and exhibited impressive supercapacitive behaviors. For example, the largest specific capacitance of HPC-2 was tested to be ca. 171 F g−1 in a three-electrode setup with outstanding rate capability and stable electrochemical property, whose capacitance retention was near 100% after cycling at rather a high current density of 40 A g−1 for up to 10,000 cycles. Furthermore, a two-electrode symmetric supercapacitor cell of HPC-2//HPC-2 was constructed, which delivered the maximum specific capacitance and energy density of ca. 30 F g−1 and 4.2 Wh kg−1, respectively, had prominent rate performance and cycling stability with negligible capacitance decay after repetitive charge/discharge at a high current density of 10 A g−1 for over 10,000 cycles. Such electrochemical properties of HPC-2 in both three- and two-electrode systems are superior or comparable to those of a great number of porous biomass carbon reported previously, hence making it a promising candidate for the development of high-performance energy storage devices.

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