Nano Energy
·
2013
·
IF 0
Wei Wen,Jin-Ming Wu,Min-Hua Cao
Rapid and economical fabrications of macroporous materials are of general interest in various fields of energy storage, energy conversion, catalysis and gas sensors. In this paper, macroporous NiO/Ni powders were achieved in a flash by the direct decomposition of a metal complex, which is template-free, surfactant-free and highly effective. The metal complex was achieved by simply mixing nickel acetate, nickel nitrate, hydrazine hydrate and glycine in water. The pore size, porosity and even morphology of the porous network (three- or two-dimensional architectures) can be conveniently tuned by adjusting the composition of the complex. It is found that, the amounts of hydrazine hydrate and glycine in the reactants affected the morphology of the porous network; whilst that of nickel acetate determined the macropores . The electrochemical performance of the achieved macroporous NiO/Ni as anodes in Li-ion batteries was comparatively investigated. The 3D macroporous NiO/Ni powders exhibited better electrochemical performances than that of 2D macroporous NiO/Ni and 3D compact NiO/Ni because of its better electrical conductivity and unique porous architecture. The presence of Ni and the continuous network of 3D structures improved the electrical conductivity of electrode materials. In addition, the macroporous architectures not only favored the ingress of electrolytes but also compensated the large volume change of the active materials during the cycling.
研究领域:
材料科学
·
能源存储与转换
·
电化学
✓ 已验证
DOI
Sustainable Energy & Fuels
·
2019
·Vol. 4
·期 1
·164-170
·
IF 4.912
Shijian Luo,Xiaoman Li,Wanguo Gao,Haiqiang Zhang,Min Luo
Today, industrial ammonia synthesis mainly depends on the Haber–Bosch process, which causes a lot of energy consumption and huge CO2 emissions. The electrochemical N2 reduction reaction (NRR) is considered a more sustainable and environmentally benign alternative to produce ammonia, but it requires an efficient catalyst to overcome the difficulty of N2 activation. In this work, we reported that MOF-derived C@NiO@Ni microtubes behaved as a high-efficiency electrocatalyst in 0.1 M KOH electrolyte. This electrocatalyst achieved a high NH3 yield of 43.15 μg h−1 mgcat.−1 and faradaic efficiency of 10.9% at −0.7 V vs. a reversible hydrogen electrode. The experimental results indicated that the excellent NRR performance originated from the oxygen vacancies in NiO. Moreover, the abundant NiO/Ni interfaces were conducive to proton adsorption and further enhanced the NRR performance.
研究领域:
材料科学
·
电化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Tianming Jia,Yanling Hao,Xiaosi Qi,Yongchao Rao,Lei Wang,Junfei Ding,Yunpeng Qu,Wei Zhong
It is well recognized that interfacial effect and/or impedance matching play a great impact on microwave absorption. Herein, we proposed a facile strategy to take full advantage of interface engineering and impedance matching for boosting microwave absorption performance (MAPs). Three-dimensional (3D) hierarchical urchin-like core@shell structured NiO/Ni@CNTs multicomponent nanocomposites (MCNCs) were elaborately constructed and produced in high efficiency through a facile continuous chemical bath deposition, thermal treatment, and catalytic chemical vapor decomposition process. By controlling the pyrolysis time, the NiO/Ni@CNTs urchin-like MCNCs with different lengths and aggregation degrees of CNTs could be selectively synthesized. The obtained results revealed that the enhanced CNT contents provided abundant interfaces and effectively aggrandized their interfacial effects, which resulted in improved polarization loss, conductivity loss, and comprehensive MAPs. Impressively, the interfaces and impedance matching in the designed NiO/Ni@CNTs urchin-like MCNCs could be optimized by regulating the pyrolysis temperature, which further improved the comprehensive MAPs. And the designed NiO/Ni@CNTs urchin-like MCNCs could simultaneously display strong absorption capabilities, broad absorption bandwidths, and thin matching thicknesses. Therefore, our findings not only provided a simple and universal approach to produce core@shell structured magnetic carbon-based urchin-like MCNCs but also presented an interface engineering and impedance matching strategy to develop the tunable, strong absorption, broadband, lightweight high-efficiency microwave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 12
·2207197
·
IF 13.3
Bei Li,Ziqian Ma,Xiao Zhang,Jia Xu,Yujin Chen,Xitian Zhang,Chunling Zhu
Hollow carbon spheres are potential candidates for lightweight microwave absorbers. However, the skin effect of pure carbon-based materials frequently induces a terrible impedance mismatching issue. Herein, small-sized NiO/Ni particles with heterojunctions on the N-doped hollow carbon spheres (NHCS@NiO/Ni) are constructed using SiO 2 as a sacrificing template. The fabricated NHCS@NiO/Ni displayed excellent microwave absorbability with a minimum reflection loss of −44.04 dB with the matching thickness of 2 mm and a wider efficient absorption bandwidth of 4.38 GHz with the thickness of 1.7 mm, superior to most previously reported hollow absorbers. Experimental results demonstrated that the excellent microwave absorption property of the NHCS@NiO/Ni are attributed to balanced dielectric loss and optimized impedance matching characteristic due to the presence of NiO/Ni heterojunctions. Theoretical calculations suggested that the redistribution of charge at the interfaces and formation of dipoles induced by N dopants and defects are responsible for the enhanced conduction and polarization losses of NHCS@NiO/Ni. The simulations for the surface current and power loss densities reveal that the NHCS@NiO/Ni has‑ applicable attenuation ability toward microwave under the practical application scenario. This work paves an efficient way for the reasonable design of small-sized particles with well-defined heterojunctions on hollow nanostructures for high-efficiency microwave absorption.
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
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 33
·335603
·
IF 3.874
Baige Yuan,Jun Li,Manman Xia,Ying Zhang,Ruyan Lei,Peng Zhao,Xiao Li
Hollow-structured NiO + Ni nanofibers wrapped by graphene were designed and successfully fabricated via a simple method. First, solid NiO + Ni nanofibers were prepared by electrospinning followed by calcination. Here, a portion of the metallic Ni was retained to improve the electrochemical performance of NiO by adjusting the calcination temperature. Next, the nanofibers were thoroughly mixed with different amounts of graphene and calcinated once more to form hollow-structured NiO + Ni nanofibers with an extremely high specific surface via the reaction between graphene and NiO on the nanofiber surface and subsequent migration of NiO into the nanofibers. Results showed that the obtained hollow-structured NiO + Ni electrode demonstrates optimal electrochemical performance when the graphene content is controlled to 3 wt%. The first cycle discharge/charge specific capacity of the electrode peaked (1596/1181 mAh · g−1 ) at 100 mA · g−1, with a coulombic efficiency of approximately 74% (60% for 0 wt% graphene, 65% for 1 wt% graphene, and 51% for 4 wt% graphene). It also presented excellent cycling stability after 100 cycles at 100 mA · g−1 on account of its high retained discharge specific capacity (251 mAh · g−1 for 0 wt% graphene, 385 mAh · g−1 for 1 wt% graphene, 741 mAh · g−1 for 3 wt% graphene, and 367 mAh · g−1 for 4 wt% graphene). Moreover, the synthesized electrode possessed outstanding rate capability owing to its large average discharge specific capacity of approximately 546 mAh · g−1 (45 mAh · g−1 for 0 wt% graphene, 256 mAh · g−1 for 1 wt% graphene, and 174 mAh · g−1 for 4 wt% graphene) from 100 mA · g−1 to 2000 mA · g−1. The observed improvement in electrochemical performance could be attributed to the increase in active sites and decrease in charge transport distance in the hollow-structured NiO + Ni nanofibers. Excessive introduction of graphene caused a sharp loss in electrochemical performance due to the agglomeration of graphene sheets on the nanofiber surfaces.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Yongchao Rao,Xiaosi Qi,Qiong Peng,Yanli Chen,Xiu Gong,Ren Xie,Wei Zhong
It was well recognized that the penetrated electromagnetic (EM) wave could be dissipated by means of magnetic loss, polarization loss and conduction loss. In order to improve their loss capacities and take full advantage of flower-like geometrical morphology, in this study, we proposed a simple route for the production of flower-like core@shell structure NiO/Ni@C microspheres through the carbon thermal reaction using NiO microflowers as precursor. The obtained results revealed that our proposed strategy successfully synthesized the core@shell structure magnetic carbon-based multicomponent nanocomposites without destroying the geometrical morphology of precursor. By regulating the annealing temperature, the as-prepared NiO/Ni@C microspheres with different contents of Ni and degrees of graphitization could be selectively synthesized, which effectively boosted their magnetic loss, polarization loss and conduction loss capabilities. Therefore, the elaborately designed NiO/Ni@C microspheres displayed the superior microwave absorption performances including strong absorption capability, broad absorption bandwidth and thin matching thicknesses compared to the NiO precursor. In summary, our findings not only provided a simple route to design and synthesize flower-like core@shell structure magnetic carbon-based nanocomposites as novel microwave absorbers, but also presented an effective strategy to comprehensively improve their loss capacities.
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
Journal of Energy Storage
·
2021
·
IF 6.583
XianYan Jiang,ShuPing Deng,JunJie Liu,Ning Qi,ZhiQuan Chen
In this work, metal oxide/metal@carbon (NiO/Ni@C) composites as electrode materials have been successfully prepared using the pillared Ni 2 (bdc) 2 (dabco) (bdc = 1,4-benzenedicarboxylic acid, dabco = 1,4-diazabicyclo[2.2.2]-octane) as the precursor. Owing to the multiple active sites (NiO, Ni and Carbon), rich oxygen defects, and abundant Ni 3 + , the NiO/Ni@C composites show excellent electrochemical performance. A maximum specific capacitance of 805.3 F g −1 at 0.5 A g −1 and 576.2 F g −1 at 10 A g −1 is obtained for the NiO/Ni@C electrode material calcined at 500 °C, indicating a high rate capability. Meanwhile, the assembled asymmetric supercapacitor (ASC) NiO/Ni@C//PEDOT-AC (poly(3,4-ethylenedioxy-thiophene)-activated carbon) has a wide working voltage of 0–1.7 V, high specific energy of 20.7 W h kg −1 , superior specific power of 12920 W kg −1 , and excellent cycle stability with capacitance retention of 69.7% after 10 000 cycles. Furthermore, a red light-emitting diode (LED) is lighted up by two NiO/Ni@C//PEDOT-AC ASCs in series connection.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Materials Advances
·
2021
·Vol. 2
·期 14
·4667-4676
·
IF 0
Qi Zhao,Jinkai Wang,Yuanyuan Cui,Xinghui Ai,Zhang Chen,Chuanxiang Cao,Feng Xu,Yanfeng Gao
Developing a highly stable electrode has been a research focus for electrochromic smart windows (ECSWs) with an ultralong cycling life. This paper reports a NiO/Ni counter electrode and the discovery of conductive ionic bonds at the NiO/Ni interface. The formation of these conductive ionic bonds between NiO and Ni is verified by electron localization function (ELF) and Bader charge analyses. Furthermore, the density of states (DOS) results reveal the metallic character of these ionic bonds. Such conductive ionic bonds stabilize the NiO lattice in the process of ion intercalation/deintercalation and weaken the electrostatic interaction between Ni and O. The experimental results show that the NiO/Ni electrode shows high visible transparency in the bleached state (90.1%), a fast switching speed (4.5 s for coloring and 5 s for bleaching) and an ultralong cycling life (87.0% retention of the original optical contrast at 550 nm after 10 000 cycles). Additionally, a 10 cm × 10 cm ECSW assembled with this NiO/Ni counter electrode and a WO3 electrode shows excellent EC performances such as large optical contrast (67.1%@550 nm, −2 V), very small transparency (lower than 1% in the wavelength range of 1600–800 nm), and a high coloration efficiency of 175.7 cm2 C−1. This work on an all-solution preparation of NiO/Ni counter electrodes represents an important step toward the development of cheap ECSWs.
研究领域:
材料科学
·
能源技术
·
光学工程
✓ 已验证
产品关联
DOI
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 35
·14970-14978
·
IF 3.288
Jingchuang Zhao,Yingzhen Zhang,Xianyu Kang,Yancai Li
Direct methanol fuel cells (DMFCs) have been extensively studied for developing a new non-precious metal catalyst to replace commercial platinum catalysts, due to their expensive cost and susceptibility to CO poisoning. In this work, nanocomposites of nickel oxide/nickel supported by N-doped carbon (NiO/Ni–N/C) were prepared by using a hydrothermal method and further carbonization at different temperatures. The surface morphology and composition of the NiO/Ni–N/C nanocomposites were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). As observed through electrochemical experiments, the NiO/Ni–N/C nanocomposite modified glassy carbon electrode (NiO/Ni–N/C/GCE) exhibits high electrocatalytic activity for the methanol oxidation reaction (MOR) in alkaline solution. Among the nanocomposites, NiO/Ni–N/C carbonized at 500 °C (NiO/Ni–N/C500) displays the highest mass activity (1043 mA mgNi−1) at 0.73 V (vs. Ag/AgCl), which is much higher than that of Ni(OH)2/N–C and NiO/Ni–N/C carbonized at other temperatures (400, 600, and 700 °C). In addition, the catalytic activity of NiO/Ni–N/C500 is 2.12 times that of the commercial Pt/C. NiO/Ni–N/C500/GCE also possesses fast kinetics, excellent stability and CO tolerance. Therefore, the NiO/Ni–N/C500 nanocomposites have great application potential as MOR catalysts.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yanqing Cong,Yanan Li,Xiaoran Wang,Xing Wei,Lin Che,Shi-Wen Lv
In this study, a double p-n heterojunction based on g-C 3 N 4 @NiO/Ni@MIL-101 ternary composite was successfully prepared by a feasible method. Results suggested that the rational growth of NiO and MIL-101 on the surface of g-C 3 N 4 can improve the absorption capacity for visible light. Importantly, the formation of double p-n heterojunction can effectively inhibit the recombination of photogenerated electrons and holes. Due to the significant Fermi level differences among NiO, MIL-101 and g-C 3 N 4 , the internal electric fields were established on the interface after constructing the composite, consequently reducing the electrical resistance and accelerating the transfer of photoinduced charge carriers. As expected, the g-C 3 N 4 @NiO/Ni@MIL-101 ternary composite with good stability had excellent photocatalytic performance in the degradation of emerging pollutants, and the removal efficiency of ibuprofen was as high as 95.6%. The •O 2 − , •OH and 1 O 2 were the major active species in the reaction system. Furthermore, developed photocatalytic oxidation system can also achieve the rapid inactivation of bacteria. Based on the synergistic effects of energy band position and double internal electric fields, the separation and transfer of photogenerated charge carriers followed a traditional type-II route. In short, current work not only constructed a promising photocatalyst, but also shared an effective strategy for boosting the photocatalytic activity.
研究领域:
材料科学
·
环境科学
·
化学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2025
·
IF 7
Lingying Chen,Jiangchuan Liu,Qinke Tang,Qingzhu Wang,Zeyang Zhang,Kai Liu,Wenrui Li,Jiguang Zhang,Rui Shi,Yana Liu,Jun Wang,Yunfeng Zhu
Active metal hydrolysis is favored for safety and environmental friendliness in the field of hydrogen generation. In practice, however, dense oxide/hydroxide films form instantaneously on the metal surface; these passivating layers act as electronic insulators that severely curtail charge transfer and, consequently, suppress hydrogen evolution. Herein, a novel heterostructure of NiO/Ni(OH)2 was designed to enhance the electron transfer rate in the magnesium powder hydrolysis system, achieving rapid hydrogen production. Surprisingly, Mg-2 wt % NiO/Ni(OH)2 achieved a near 100% conversion rate, producing 880.2 mL g–1 of H2 in only 20 s at 30 °C. Its maximum hydrogen generation rate (mHGR) surpassed that of pure magnesium by 35-fold, and such hydrolysis performance is superior to all the reported results of catalyzed-Mg systems so far. Theoretical studies confirmed that the space charge region in NiO/Ni(OH)2 affects the electronic structure; thus, the correspondingly generated built-in electric field accelerated the hydrolysis of magnesium and greatly facilitated the electron transfer of the system. This work provides a strategy for designing nickel-based oxides/hydroxides catalysts for light metal hydrolysis and facilitates the understanding of the catalytic mechanism in multiphase catalytic systems.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Ru Song,Ningshuang Zhang,Peng Wang,Hao Ding,Shiyou Li
The scarcity of freshwater resources and energy crisis are major challenges to the progress of human society. Recently, solar-driven interfacial water evaporation utilizes photothermal conversion materials to convert solar energy into thermal energy , which possesses great application potential in seawater desalination and sewage treatment . Here, we fabricated porous nickel sponge (NSP) composite photothermal material (NiO-NSP) containing abundant NiO nanoneedles array. This in situ-grown NiO with enhanced bonding between photothermal material and substrate can be used as a solar absorber directly without consuming additional photothermal material compared to conventional coating and cladding on the carrier surface. Due to the multi-scattering induced light trapping effect of the semiconductor NiO nanoneedles array on the surface of nickel fibers, resulting in light absorption up to 96.5 %. NiO-NSP evaporators have an abundance of interconnected porous channels for water supply , which results in strong capillary action to pump water to the evaporation interface efficiently. Moreover, the highly dispersed nanoneedles array expand the evaporation surface area. Consequently, the NiO-NSP evaporator delivers an excellent evaporation rate of 1.78 kg m −2 h −1 and a photothermal conversion efficiency of 84.7 % at one sun radiation. In addition, the micron-sized porous mesh structure of NiO-NSP dissolve salt crystals and diffuse them downward into the bulk brine, exhibiting excellent salt resistance and remarkable seawater desalination stability. Moreover, NiO-NSP solar evaporators has been demonstrated to possess excellent ability to purify dye and heavy metal ion wastewater. Therefore, the NiO-NSP high-performance evaporator produced by straightforward process proved to be suitable for solar seawater desalination and wastewater purification.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）