ACS Omega
·
2018
·
IF 0
Anning Jiang,Nagapradeep Nidamanuri,Chenyun Zhang,Zhonghao Li
The sluggish oxygen evolution reaction (OER) hinders the development of electrocatalytic water splitting for energy conversion and storage. Therefore, it is imperative to explore the cost-effective and highly efficient noble-metal-free electrocatalysts for OER. Herein, we are introducing such OER electrocatalyst based on Co, fabricated through an ionic-liquid-assisted one-step synthesis, where ionic liquid played a dual role as solvent cum structure-directing agent. Besides possessing large-accessible surface area and numerous active sites, the as-prepared stable CoO nanosheets exhibited excellent electrochemical activity through establishing an extensive contact with the electrolyte. Under alkaline conditions, the overpotential to achieve a current density of 10 mA cm–2 is only 320 mV, and the Tafel slope is as small as 70 mV dec–1. Thus, our work provides a new pathway for designing and engineering the highly efficient non-noble metal OER electrocatalysts by using ionic liquids.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
ChemNanoMat
·
2023
·Vol. 9
·期 3
·e202200521
·
IF 3.8
Xinjie Guo,Xingyu Gan,Yun Wang,Xiaoxia Lv,Fengxiang Wang,Shuxin Wang,Shan Peng
Graphical A Co/CoO@NC/CNT-10 catalyst was effectively synthesized using melamine-assisted pyrolysis with Co-MOF as the precursor. With the synergistic effect of metal species, oxygen defects and N-doped carbon nanotubes, the intrinsic activity and electron transfer ability of the catalysts were greatly improved, showing excellent electrocatalytic oxygen reduction performance. Low-cost and high-efficiency oxygen reduction reaction (ORR) electrocatalysts are the basis for large-scale applications of electrochemical energy storage and conversion technologies such as fuel cells and metal-air batteries. Herein, cobalt and oxygen vacancy-rich cobalt oxide encapsulated in nitrogen-doped carbon and carbon nanotubes (Co/CoO@NC-CNTs) have been prepared by direct solid-state pyrolysis of Co-MOF. The carbon morphology, oxygen vacancy content and type of nitrogen can be finely tuned by mixing Co-MOF with proper amounts of melamine. The optimized material has an interwoven CNT structure with abundant micro- and mesopores, suitable nitrogen type and certain number of oxygen vacancies and exhibiting outstanding ORR electrocatalytic performance in alkaline media with an onset potential of 0.96 V and a half-wave potential of 0.88 V vs RHE, which is higher than 20 wt% Pt/C, as well as being highly stable and well resistant to methanol.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2023
·Vol. 25
·期 13
·1915-1927
·
IF 3.1
Yuan Song,Qiang Shen,Guo-Xiang Pan,Chao Ye,Yi-Fan Zhang,Lin Song
CoO and CoAl layered double hydroxide (CoAl-LDH) are both promising active electrode materials for pseudocapacitors. It is of great significance to integrate the advantages of both materials and design ingenious electrode structures to achieve high electrochemical performance. Herein, 3D core–shell CoO@CoAl-LDH nanobouquet arrays on Ni foam were fabricated via two-step hydrothermal growth methods, where CoAl-LDH nanoflakes regularly grew on the surface of CoO nanosheets. The composite exhibits superior specific capacitance (2031.2 F g−1 at 1 A g−1) and desirable cycling stability (88.2% after 5000 cycles at 16 A g−1). Asymmetric supercapacitors (ASCs) devices were also assembled using an as-synthesized CoO@CoAl-LDH composite as a positive electrode and activated carbon (AC) as a negative electrode. The electrochemical test of ASCs provides a specific capacitance of 195.6 F g−1 at 1 A g−1, and the devices retained approximately 85% of the capacitance after 5000 cycles. The ASCs display a high energy density of 69.55 W h kg−1 at a high-power density of 800 W kg−1 and remained at 29.2 W h kg−1 even at a higher power density of 12 800 W kg−1. The electrochemical mechanism was discussed. This work offers a meaningful perspective to explore the possibility of supercapacitor applications of LDH-based materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yuan Shu,Tingkai Zhao,Weiyu Jia,Lei Yang,Xianghong Li,Guyue Feng,Yatao Li,Fa Luo
The combination of magnetic and dielectric materials followed by appropriate structure design is an effective approach to achieve high electromagnetic wave absorption properties. Here, crosslinked Co@CoO/reduced graphene oxide nanohybrids (CCRGO) were fabricated via a simple three-step method. The experimental results show that compared with previous works, the as-prepared CCRGO nanohybrids achieve higher electromagnetic wave absorption and broader effective bandwidth at a lower filler loading. The electromagnetic parameters and electromagnetic wave absorption performance could be apparently adjusted by controlling the adding content of graphene oxide (GO) and the reduction temperature. Among a series of samples, CCRGO3-650 nanohybrid yields the best electromagnetic wave absorption performance benefiting from the proper GO addition and reduction temperature. At a filler loading of 20 wt%, the maximal reflection loss reaches to −64.67 dB at a thickness of 2.53 mm and the effective bandwidth below −10 dB covers the whole X band at a thickness of 2.51 mm. The good performance may be ascribed to the advantages of the dielectric and magnetic component as well as the special crosslinked structure, which triggers a synergistic absorption mechanism including multiple reflection/scattering, interface polarization, dipole polarization, conductive loss, eddy current loss, exchange resonance in the electromagnetic wave dissipation process. The good electromagnetic wave absorption performance affirms the potential application of CCRGO nanohybrids in the field of stealth materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2023
·
IF 17.1
Chuansheng He,Linlin Yang,Xiaohui Peng,Shangheng Liu,Jia Wang,Chengyuan Dong,Delin Du,Leigang Li,Lingzheng Bu,Xiaoqing Huang
Thickness regulation of transition metal hydroxides/oxides nanosheets with superior catalytic properties represents a promising strategy to enhance catalytic performance, but it remains an enormous challenge to achieve precise control, especially when it comes to the ultrathin limit (several atomic layers). In this work, a facile strategy of alkylamine-confined growth is proposed for the synthesis of thickness-tunable metal hydroxide/oxide nanosheets. Specifically, ultrathin cobalt hydroxide and cobaltous oxide hybrid (Co(OH)2-CoO) nanosheets (Co–O NSs) with a thickness in the range of 2–6 nm (5–13 atomic layers) are synthesized by using alkylamines with different carbon chain lengths as the ligand to modulate vertical coordination ability. Co–O NSs with a thickness of 2 nm (Co–O NSs-2 nm) exhibit excellent oxygen evolution reaction (OER) performance with an overpotential of 278 mV at 10 mA/cm2. The maximized number of active sites including oxygen vacancies, optimal adsorption strength, and the highest electrical conductivity are considered as the potential factors contributing to the excellent OER performance of Co–O NSs-2 nm. This work holds great significance for the precise thickness-tunable synthesis of transition metal layered hydroxide nanosheets with modulated and improved catalytic performance.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 38
·26196-26202
·
IF 3.3
Zhijun Wang,Ying Xiong,Limin Liu,Lili Xia,Yinfeng Wang,Xuexia Liu
In recent years, bifunctional electrocatalysts, nanomaterials directly grown on the substrate for application towards the hydrogen evolution reaction (HER), have become of interest for sustainable and clean energy technologies. However, the influence of interfacial interactions between the electrode materials and substrate on device performance remains unclear and is rarely investigated. Herein, we report two-dimensional (2D) CoO nanosheets grown on carbon cloth (CC) (2D CoO/CC) to construct a hybrid electrocatalyst with a seamlessly conductive network. By a series of structure analyses, we recommend that the CoO nanosheets and CC are connected via adsorption. The 2D CoO/CC nanosheets show superior HER performance to the commercial Pt/C and CoO(aq.)/CC nanosheets, including onset potentials of 2 mV, low overpotential of 22 mV at 10 mA cm−2 and Tafel slope of 37 mV dec−1. The results of density functional theory (DFT) calculations reveal that the adsorbability plays an important role in determining the performance of the electrocatalysts for the HER. This work provides a new insight into the interfacial interactions between the electrode material and the substrate in electrochemical devices, and paves the way for the rational design and construction of high-performance electrochemical devices for practical energy applications.
研究领域:
材料科学
·
能源技术
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yang Zhu,Tongfeng Cai,Huangping Rui,Xiangyao Gu,Xueqin Mu,Yu Tong,Haibao Duan,Changyun Chen,Suli Liu,Shichun Mu
The surface configuration of low‐cost spinel oxides for oxygen evolution reaction (OER) can significantly affect the electrochemical behavior by generating a thin oxyhydroxide layer and other structures on the surface. Herein, we design and construct phosphorus (P)-activated ~1.0 nm ultrathin CoO nanosheets (devoted as P x -CoO NSs) with enriched P-O bonds and high valence state Co active sites, which is beneficial to the OER process due to the balance with Co 3+ and oxygen vacancies on the reconstructed surface/interface. In addition, such an ultrathin nanosheet structure is also benefit to expose more active sites and improve the intrinsic electronic conductivity. As a result, the surface reconstructed P x -CoO NSs show superior OER activity compared with pure CoO and IrO 2 as benchmark. Furthermore, P 1 -CoO NSs demonstrate intrinsically high mass activity of 6.8 A g Co −1 at an overpotential of 270 mV, large turnover frequency of 0.0024 s −1 at an overpotential of 300 mV, and strong cycling stability in 0.1 M KOH solutions. Structural analysis further reveals that, as compared with CoO, the P-substitution not only induces the surface reconstruction into active Co oxyhydroxides under OER conditions, but also enhances the reaction kinetics. Undoubtedly, this work enriches the ways to prepare high-performance transition-metal-oxide-based catalyst for practical applications.
研究领域:
材料科学
·
电化学
·
催化
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 48
·24767-24772
·
IF 9.931
Rui-Qing Li,Pengfei Hu,Meng Miao,Yongle Li,Xiang-Fen Jiang,Qiang Wu,Zhen Meng,Zheng Hu,Yoshio Bando,Xue-Bin Wang
Obtaining a high-performance nonprecious electrocatalyst for oxygen and hydrogen evolution reactions (OER and HER) under mild conditions is highly desirable yet challenging. Transition metal nitrides are emerging as cost-effective substitutes for state-of-the-art noble metal based catalysts, but large OER overpotentials plague these nitrides. Herein, we developed the heterostructure of CoO-domain-anchored Co4N nanowhiskers as an effective bifunctional electrocatalyst for both OER and HER in neutral media. The exterior CoO targets OER, and the CO4N matrix is active for HER. The periodically-aligned {111} crystalline planes between Co4N and CoO provide good electron transport through their interface. The heterostructure performs dual functions of elevating activity and diminishing interior resistance of the catalyst. Moreover, the porous metallic Co4N nanowhiskers were integrated on a nickel foam, and this configuration contributes an arterial channel for collecting current as well as a spacious surface area for increasing the reaction cross section for heterocatalysis. These advantages actuate our bifunctional 3D catalytic electrode to achieve low OER and HER overpotentials in neutral systems. It finally provides an unprecedentedly low cell voltage (1.79 V for 10 mA cm−2) for catalyzing overall water splitting in neutral media.
研究领域:
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
IONICS
·
2017
·Vol. 24
·期 5
·1321-1328
·
IF 2.062
Zhou Rihui,Chen Yaqin,Fu Yuanyuan,Li Yanfei,Chen Shouhui,Song Yonghai,Wang Li
A novel graphene (G)-Co/CoO shaddock peel-derived carbon foam (SPDCF) hybrid was fabricated as anode materials for lithium-ion batteries. The preparation of G-Co/CoO SPDCF was according to the following two steps. Firstly, the dried shaddock peels were immersed into the mixture of Co(NO 3 ) 2 /graphene oxide for about 12 h. Then, the shaddock peels were taken out and heated at 800 °C for 2 h under N 2 atmosphere. The strategy is simple, low-cost, and environmentally friendly because the shaddock peel is abundant and renewable. The obtained G-Co/CoO SPDCF hybrid were carefully characterized by SEM, EDS, XPS, XRD, TGA, BET, TEM, and electrochemical techniques. The results showed that the carbonized shaddock peels had hierarchical porous nanoflakes structures and graphene was uniformly dispersed into the SPDCF. The nanosized Co/CoO was formed on the G-SPDCF. The resulted G-Co/CoO SPDCF hybrid could maintain a high capacity of 600 mA h g −1 at 0.2 A g −1 after 80 cycles, which was much higher than that of commercial graphite (372 mA h g −1 ). The enhanced performance might be ascribed to the existence of lots of uniform Co/CoO and the hierarchical G-SPDCF alleviating the mechanical stress during the process of lithiation/delithiation.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
Nano-Micro Letters
·
2020
·Vol. 13
·期 1
·1-15
·
IF 12.264
Tian Yuhui,Xu Li,Li Meng,Yuan Ding,Liu Xianhu,Qian Junchao,Dou Yuhai,Qiu Jingxia,Zhang Shanqing
Interface engineering of heterogeneous CoS/CoO nanocrystals and N-doped graphene composite facilitates high-performance oxygen reduction reaction and oxygen evolution reaction.
Density functional theory calculations and experimental results confirm the enhanced electrocatalytic performances via the proposed interface engineering.
The bifunctional oxygen electrocatalyst exhibits excellent performances in rechargeable Zn–air batteries.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
催化化学
·
先进电池技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 14
·22727-22732
·
IF 3.83
Xu Chen,Xi Sun,Jing Zhou,Defeng Zhou,Xiaofei Zhu,Jian Meng
Nd 0.2 Ce 0.8 O 3-δ (NDC) is one of the most common solid electrolyte materials used in solid oxide fuel cells (SOFCs). However, the densification temperature of NDC electrolyte is above 1400 °C. In this work, Bi 2 O 3 and CoO sintering aids were individually or synergistically added to Nd 0.2 Ce 0.8 O 3-δ (NDC) electrolytes through the sol-gel method to lower its sintering temperature . Effects of Bi 2 O 3 -CoO dual sintering aid on the sintering behavior, phase composition, microstructure, and electrochemical properties of NDC electrolyte were all investigated. The data revealed that Bi 2 O 3 -CoO dual-sintering aid doped-NDC (labeled as NDC-CB) possessed high density and superior conductivity at low temperatures, better than that of Bi 2 O 3 or CoO single sintering aid. NDC electrolyte doped with Bi 2 O 3 -CoO dual-sintering aid achieved highest relative density of 95.3% at 1100 °C and total conductivity of 5.765 × 10 -2 S cm -1 at 800 °C. Furthermore, NDC-CB displayed excellent physical and chemical compatibility with La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ (LSCF) cathode and NiO-NDC anode. Oxygen reduction reaction at LSCF/NDC-CB interface was improved by about 40% when compared to NDC. In sum, Bi 2 O 3 -CoO looks promising as dual-sintering additive for lowing sintering temperature and increasing electrical conductivity of NDC. Therefore, NDC-CB might be potential electrolyte for future intermediate-temperature solid oxide fuel cells (IT-SOFCs).
研究领域:
材料科学
·
电化学
·
能源材料
·
陶瓷
·
燃料电池
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Yixiang Pan,Xiaoyan Wang,Jianguo Lu,Qing Yan,Weiyong Yuan,Chang Ming Li
Metal–organic complex (MOC) multilayers are, for the first time, conformally constructed on Ni foam (NF) via a three-component sequential layer-by-layer (LbL) self-assembly approach and converted to three-dimensional (3-D) NF-supported interconnected CoO nanoparticles (NPs)/N-doped carbon nanohybrid multilayers via calcination. The obtained nanoarchitecture delivers an overpotential of 318 mV to achieve 10 mA cm–2 and a Tafel slope of 46.1 mV dec–1. This activity is superior to most reported oxygen evolution reaction (OER) catalysts, and even much better than those of Ir- and Ru-based ones measured under the same conditions (0.1 M KOH). Additionally, this electrode undergoes negligible potential and current change after 19.8 h chronopotentiometric measurement and 300 cyclic voltammetry cycles. The outstanding catalytic performance is mainly attributed to the ultrasmall and high-density CoO NPs embedded in N-doped carbon uniformly assembled on the 3-D substrate significantly increasing electrochemically accessible active sites and durability and the N-doped carbon greatly promoting intrinsic activity of CoO. This work not only creates 3-D highly tunable networked nanostructured electrodes with excellent durability for high-efficiency electrocatalysis but also develops a facile, economical, and extremely versatile strategy to controllably self-assemble conformal MOC-based multilayers with multifunctionality and superior performance on essentially any substrate at the molecular level for broad applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）