Construction of NiCoZnS materials with controllable morphology for high-performance supercapacitors

2021 ◽  
Author(s):  
Zifeng Tian ◽  
hongyan zeng ◽  
Shi-Bing Lv ◽  
YiWen Long ◽  
Sheng Xu ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Metal Sulfide ◽  
Molar Ratio ◽  
Electrochemical Performances ◽  
Long Cycle Life ◽  
Hydrothermal Approach ◽  
Mixed Transition ◽  
Asymmetric Device

Abstract A facile two-step hydrothermal approach with post-sulfurization treatment was put forward to construct the mixed transition metal sulfide (NiCoZnS) with a high electrochemical performance. The different morphologies of NiCoZnS materials were successfully fabricated by adjusted the Ni/Co molar ratio of the NiCoZn(OH)F precursor. Moreover, the in-situ phase transformation from the NiCoZn(OH)F phase to Zn0.76Co0.24S and NiCo2S4 phases and lattice defects via the S2− ion-exchange were determined by XRD, TEM and XPS techniques, which improved electric conductivity and interfacial active sites of the NiCoZnS, and so promoted the reaction kinetics. Significantly, the urchin-like NiCoZnS1/1 prepared at the Ni/Co molar ratio of 1.0 exhibited promising electrochemical performances with high capacitance and excellent cycling stability. Furthermore, the asymmetric device (NiCoZnS//AC) using NiCoZnS1/1 as the positive electrode had excellent supercapacitor performances with an energy density of 57.8 Wh·kg–1 at a power density of 750 W·kg–1 as well as a long cycle life (79.2% capacity retention after 10000 cycles), indicating the potential application in high-performance supercapacitors.

scholarly journals N, S and Transition-Metal Co-Doped Graphene Nanocomposites as High-Performance Catalyst for Glucose Oxidation in a Direct Glucose Alkaline Fuel Cell

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 202
Author(s):  
Yexin Dai ◽  
Jie Ding ◽  
Jingyu Li ◽  
Yang Li ◽  
Yanping Zong ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
High Performance ◽  
Glucose Oxidation ◽  
Alkaline Fuel Cell ◽  
Blank Group ◽  
Graphene Nanocomposites ◽  
Doped Graphene ◽  
One Step ◽  
Hydrothermal Approach

In this work, reduced graphene oxide (rGO) nanocomposites doped with nitrogen (N), sulfur (S) and transitional metal (Ni, Co, Fe) were synthesized by using a simple one-step in-situ hydrothermal approach. Electrochemical characterization showed that rGO-NS-Ni was the most prominent catalyst for glucose oxidation. The current density of the direct glucose alkaline fuel cell (DGAFC) with rGO-NS-Ni as the anode catalyst reached 148.0 mA/cm2, which was 40.82% higher than the blank group. The DGAFC exhibited a maximum power density of 48 W/m2, which was more than 2.08 folds than that of blank group. The catalyst was further characterized by SEM, XPS and Raman. It was speculated that the boosted performance was due to the synergistic effect of N, S-doped rGO and the metallic redox couples, (Ni2+/Ni3+, Co2+/Co3+ and Fe2+/Fe3+), which created more active sites and accelerated electron transfer. This research can provide insights for the development of environmental benign catalysts and promote the application of the DGAFCs.

scholarly journals Requirements for Beneficial Electrochemical Restructuring: A Model Study on a Cobalt Oxide in Selected Electrolytes

2021 ◽  
Author(s):  
Javier Villalobos ◽  
Diego Gonzales-Flores ◽  
Roberto Urcuyo ◽  
Mavis L. Montero ◽  
Götz Schuck ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Rational Design ◽  
Local Order ◽  
Current Increase ◽  
Model Study ◽  
Redox Active ◽  
Open Question ◽  
Diffraction Microscopy

<p>The requirements for beneficial materials restructuring into a higher performance OER electrocatalyst are still a largely open question. Here we use Erythrite (Co<sub>3</sub>(AsO<sub>4</sub>)<sub>2 </sub>8H<sub>2</sub>O) as a Co-based OER electrocatalyst to evaluate its catalytic properties during in-situ restructuring into an amorphous Co-based catalyst in four different electrolytes at pH 7. Using diffraction, microscopy and spectroscopy, we observed a strong effect in the restructuring kinetics depending of the anions in the electrolyte. Only carbonate electrolyte could activate the catalyst electrode, which we relate to its slow restructuring kinetics. While its turnover frequency (TOF) reduced from 2.84 O<sub>2 </sub>Co<sup>-1 </sup>s<sup>-1</sup> to a constant value of 0.10 O<sub>2</sub> Co<sup>-1 </sup>s<sup>-1</sup> after ~ 300 cycles, the number of redox active sites continuously increased, which explained the current increase of around 100%. The final activated material owns an adequate local order, a high Co oxidation state and a high number of redox-active Co ions, which we identify as the trinity for enhancing the OER activity. Thus, this work provides new insights into for the rational design of high-performance OER catalysts by electrochemical restructuring.</p>

Hierarchical Cu(OH)2@Ni2(OH)2CO3 core/shell nanowire arrays in situ grown on three-dimensional copper foam for high-performance solid-state supercapacitors

2017 ◽  
Vol 5 (20) ◽  
pp. 9960-9969 ◽  
Author(s):  
Sheng Zhu ◽  
Zidan Wang ◽  
Fangzhi Huang ◽  
Hui Zhang ◽  
Shikuo Li
Keyword(s):  
Solid State ◽  
High Performance ◽  
Three Dimensional ◽  
Nanowire Arrays ◽  
Core Shell ◽  
Electrochemical Performances ◽  
Copper Foam

Well-aligned hierarchical Cu(OH)2@Ni2(OH)2CO3 core/shell nanowire arrays in situ grown on conductive copper foams as binder- and conductive-free electrodes display superior electrochemical performances.

scholarly journals Hollow CoP/FeP4 Heterostructural Nanorods Interwoven by CNT as a Highly Efficient Electrocatalyst for Oxygen Evolution Reactions

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1450
Author(s):  
Yanfang Liu ◽  
Yong Li ◽  
Qi Wu ◽  
Zhe Su ◽  
Bin Wang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Oxygen Evolution ◽  
Water Oxidation ◽  
Active Sites ◽  
High Performance ◽  
Hydrothermal Reaction ◽  
Clean Energy ◽  
Electrochemical Performances ◽  
Ion Diffusion ◽  
Kinetics Of

Electrolysis of water to produce hydrogen is crucial for developing sustainable clean energy and protecting the environment. However, because of the multi-electron transfer in the oxygen evolution reaction (OER) process, the kinetics of the reaction is seriously hindered. To address this issue, we designed and synthesized hollow CoP/FeP4 heterostructural nanorods interwoven by carbon nanotubes (CoP/FeP4@CNT) via a hydrothermal reaction and a phosphorization process. The CoP/FeP4@CNT hybrid catalyst delivers prominent OER electrochemical performances: it displays a substantially smaller Tafel slope of 48.0 mV dec−1 and a lower overpotential of 301 mV at 10 mA cm−2, compared with an RuO2 commercial catalyst; it also shows good stability over 20 h. The outstanding OER property is mainly attributed to the synergistic coupling between its unique CNT-interwoven hollow nanorod structure and the CoP/FeP4 heterojunction, which can not only guarantee high conductivity and rich active sites, but also greatly facilitate the electron transfer, ion diffusion, and O2 gas release and significantly enhance its electrocatalytic activity. This work offers a facile method to develop transition metal-based phosphide heterostructure electrocatalysts with a unique hierarchical nanostructure for high performance water oxidation.

In situ formation of porous graphitic carbon wrapped MnO/Ni microsphere networks as binder-free anodes for high-performance lithium-ion batteries

2018 ◽  
Vol 6 (26) ◽  
pp. 12316-12322 ◽  
Author(s):  
Xiangzhong Kong ◽  
Anqiang Pan ◽  
Yaping Wang ◽  
Dinesh Selvakumaran ◽  
Jiande Lin ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
High Performance ◽  
Lithium Ion ◽  
Porous Graphitic Carbon ◽  
Graphitic Carbon ◽  
Electrochemical Performances ◽  
Binder Free ◽  
In Situ Formation

Porous graphitic carbon wrapped MnO/Ni microsphere networks exhibit excellent electrochemical performances when used as binder-free anodes for LIBs.

Interface modulation of a layer-by-layer electrodeposited FexCo(1−x)P/NiP@CC heterostructure for high-performance oxygen evolution reaction

2020 ◽  
Vol 4 (4) ◽  
pp. 1863-1874 ◽  
Author(s):  
Bezawit Z. Desalegn ◽  
Harsharaj S. Jadhav ◽  
Jeong Gil Seo
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Oxygen Evolution ◽  
Alkaline Medium ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
High Performance ◽  
Layer By Layer ◽  
Interface Modulation

Heterostructuring assisted trimetallic transition metal phoshide with in situ generated active sites, exhibits superior catalytic activity towards oxygen evolution reaction in alkaline medium.

Preparation and Characterization of NiO/YSZ Cathode and BSCF/SDC Anode of SOEC for Hydrogen Production

2011 ◽  
Vol 287-290 ◽  
pp. 2494-2499 ◽  
Author(s):  
Bo Yu ◽  
Ming Fen Wen
Keyword(s):  
Hydrogen Production ◽  
Composite Powder ◽  
Combustion Method ◽  
Molar Ratio ◽  
Future Application ◽  
Electrochemical Performances ◽  
Potential Candidate ◽  
Temperature Application ◽  
Surface Morphologies

In this paper, NiO-YSZ composite powder was synthesized via in situ urea combustion method to prepare high homogeneity cathode. Sm0.2Ce0.8O1.9(SDC) is used as a barrier interlayer between Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) anode and 8YSZ electrolyte to avoid solid state interaction for high temperature application. The crystal structure and surface morphologies of NiO, YSZ, BSCF and SDC powders were characterized, respectively. The optimization of technological conditions for the synthesis was investigated. The adding amount was calculated by the combustion reaction equation. BSCF-SDC/YSZ/Ni-YSZ single button cells were prepared and the related electrochemical performances were test at 850°C. The research results showed that the products were well crystallized with NiO coating on YSZ particles. The optimized addition of CO(NH2)2to Ni(NO3)2was 2:1. A SOEC single cell made from NiO-YSZ with the molar ratio of 2:1 composite powder exhibited better performance than the other samples with the electrolytic voltage of 0.98V and showed excellent durability under the electrolytic currency of 0.33 A/cm2, the input stream of 90%H2O+10%H2. The hydrogen production rate of the single SOEC using BSCF/SDC can be up to 196.6 mL·cm-2h-1, which indicates that it could be a potential candidate for the future application of SOEC technology.

High sulfur content microporous carbon coated sulfur composites synthesized via in situ oxidation of metal sulfide for high-performance Li/S batteries

2017 ◽  
Vol 5 (13) ◽  
pp. 6052-6059 ◽  
Author(s):  
Qian Wang ◽  
Zhen-Bo Wang ◽  
Chao Li ◽  
Da-Ming Gu
Keyword(s):  
Sulfur Content ◽  
Hollow Sphere ◽  
High Performance ◽  
Oxidation Process ◽  
Metal Sulfide ◽  
Microporous Carbon ◽  
In Situ Oxidation ◽  
High Sulfur Content ◽  
Carbon Coated

Microporous carbon coated sulfur composites with a double-hollow-sphere structure are prepared through anin situoxidation process.

scholarly journals Origin of Enhanced Water Oxidation Activity in an Iridium Single Atom Catalyst

2021 ◽  
Author(s):  
Xueli Zheng ◽  
Jing Tang ◽  
Alessandro Gallo ◽  
Jose Antonio Garrido Torres ◽  
Xiaoyun Yu ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Active Sites ◽  
High Performance ◽  
Operating Conditions ◽  
Utilization Efficiency ◽  
Oxidation Catalyst ◽  
Single Atom ◽  
Photochemical Reduction ◽  
Oxidation Activity

<p>The efficiency of the synthesis of renewable fuels and feedstocks from electrical sources is limited at present by the sluggish water oxidation reaction. Single atom catalysts (SACs) with a controllable coordination environment and exceptional atom utilization efficiency open new paradigms towards designing high performance water oxidation catalysts. Here, using<i> operando</i> X-ray absorption spectroscopy measurements with calculations of spectra and electrochemical activity, we demonstrate that the origin of water oxidation activity of IrNiFe SACs is the presence of highly oxidized Ir single atom (Ir<sup>5.3+</sup>)<sup> </sup>in the NiFe oxyhydroxide under operating conditions. We show that the optimal water oxidation catalyst could be achieved by systematically increasing the oxidation state and modulating the coordination environments of the Ir active sites anchored atop the NiFe oxyhydroxide layers. Based on the proposed mechanism, we have successfully anchored Ir single-atom sites on NiFe oxyhydroxides (Ir<sub>0.1</sub>/Ni<sub>9</sub>Fe SAC) via a unique<i> in situ</i> cryogenic photochemical reduction (<i>in situ</i> Cryo-PCR) method which delivers an overpotential of 183 millivolts at 10 milliamperes per square centimeter and retains its performance following 20 hours of operation in 1 M KOH electrolyte, outperforming the reported catalysts and the commercial IrO<sub>2</sub> catalysts. These findings open the avenue towards atomic-level understanding of oxygen evolution of catalytic centers under <i>in operando</i> condition.</p>

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