共查询到20条相似文献,搜索用时 31 毫秒
1.
以CoCl2·6H2O为原料,通过溶剂热法和磷化工艺在泡沫镍表面构建Co2P4O12阵列,Co2P4O12纳米线直径约200 nm。采用SEM、TEM和XRD进行形貌和晶体学特性表征,并利用三电极体系在碱性环境下测量电化学性能。在析氢过程中,只需要122 mV过电位就能达到10 mA·cm-2电流密度。析氧过程中,仅需要334 mV的过电位就能达到15 mA·cm-2电流密度。组装的电解池在15 mA·cm-2的电流密度下工作40 h后电解槽电压没有发生明显变化,展现出很好的稳定性。Co2P4O12/NF是一种有潜力的双功能催化剂。 相似文献
2.
在室温下利用NaBH4溶液还原Co3O4纳米线获得富含氧空位(VO)的三维自支撑纳米线阵列用作全水解电催化剂,其中NaBH4处理10 min的Co3O4/NF在碱性介质中对析氧反应(OER)和析氢反应(HER)表现出很高的活性,在10 mA·cm-2电流密度下分别仅需240和132 mV的过电位。VO-Co3O4/NF同时作为阴极和阳极电催化剂时,在10 mA·cm-2下电解水槽电压仅为1.63 V,其耐久性可达60 h以上。该工作为富含氧空位结构的过渡金属氧化物双功能电催化剂的制备提供了新的方法和思路。 相似文献
3.
Engineering oxygen vacancy-rich Co3O4 nanowire as high-efficiency and durable bifunctional electrocatalyst for overall alkaline water splitting
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A novel kind of vacancy-rich nanowire arrays were prepared by reducing rough Co3O4 nanowires with NaBH4 solution on 3D nickel foam at room temperature for overall water splitting. Co3O4/NF treated by NaBH4 for 10 min was highly active for oxygen evolution reaction (OER) and simultaneously efficient for hydrogen evolution reaction (HER) with the need of the overpotentials of 240 and 132 mV to drive 10 mA·cm-2 in alkaline media, respectively. Furthermore, the electrocatalysts as both cathode and anode in a two-electrode system presented excellent durability for over 60 h at 10 mA·cm-2, maintaining the cell voltage of merely 1.63 V. This work provides new methods and ideas for the preparation of transition metal oxide bifunctional electrocatalysts rich in oxygen vacancies. 相似文献
4.
Zihuan Yu Haiqing Yan Chaonan Wang Zheng Wang Huiqin Yao Rong Liu Cheng Li Shulan Ma 《Frontiers of Chemical Science and Engineering》2023,17(4):437
High-performance and ultra-durable electrocatalysts are vital for hydrogen evolution reaction (HER) during water splitting. Herein, by one-pot solvothermal method, MoOx/Ni3S2 spheres comprising Ni3S2 nanoparticles inside and oxygen-deficient amorphous MoOx outside in situ grow on Ni foam (NF), to assembly the heterostructure composites of MoOx/Ni3S2/NF. By adjusting volume ratio of the solvents of ethanol to water, the optimized MoOx/Ni3S2/NF-11 exhibits the best HER performance, requiring an extremely low overpotential of 76 mV to achieve the current density of 10 mA∙cm‒2 (η10 = 76 mV) and an ultra-small Tafel slope of 46 mV∙dec‒1 in 0.5 mol∙L‒1 H2SO4. More importantly, the catalyst shows prominent high catalytic stability for HER (> 100 h). The acid-resistant MoOx wraps the inside Ni3S2/NF to ensure the high stability of the catalyst under acidic conditions. Density functional theory calculations confirm that the existing oxygen vacancy and MoOx/Ni3S2 heterostructure are both beneficial to the reduced Gibbs free energy of hydrogen adsorption (|∆GH*|) over Mo sites, which act as main active sites. The heterostructure effectively decreases the formation energy of O vacancy, leading to surface reconstruction of the catalyst, further improving HER performance. The MoOx/Ni3S2/NF is promising to serve as a highly effective and durable electrocatalyst toward HER. 相似文献
5.
Tongzhou Lu Yongzheng Zhang Chun Cheng Yanbin Wang Yongming Zhu 《Frontiers of Chemical Science and Engineering》2020,14(4):595
A facile one-step hydrothermal method has been adopted to directly synthesize the CuCo2S4 material on the surface of Ni foam. Due to the relatively large specific surface area and wide pore size distribution, the CuCo2S4 material not only effectively increases the reactive area, but also accommodates more side reaction products to avoid the difficulty of mass transfer. When evaluated as anode for Li-ion batteries, the CuCo2S4 material exhibits excellent electrochemical performance including high discharge capacity, outstanding cyclic stability and good rate performance. At the current density of 200 mA·g−1, the CuCo2S4 material shows an extremely high initial discharge capacity of 2510 mAh·g−1, and the cycle numbers of the material even reach 83 times when the discharge capacity is reduced to 500 mAh·g−1. Furthermore, the discharge capacity can reach 269 mAh·g−1 at a current of 2000 mA·g−1. More importantly, when the current density comes back to 200 mA·g−1, the discharge capacity could be recovered to 1436 mAh·g−1, suggesting an excellent capacity recovery characteristics. 相似文献
6.
Hongtao Xie Qin Geng Xiaoyue Liu Jian Mao 《Frontiers of Chemical Science and Engineering》2022,16(3):376
To realize renewable energy conversion,it is important to develop low-cost and high-efficiency electrocatalyst for oxygen evolution reaction.In this communication,a novel bijunction CoS/CeO2 electrocatalyst grown on carbon cloth is prepared by the interface engineering.The interface engineering of CoS and CeO2 facilitates a rapid charge transfer from CeO2 to CoS.Such an electrocatalyst exhibits outstanding electrocatalytic activity with a low overpotential of 311 mV at 10 mA·cm?2 and low Tafel slope of 76.2 mV·dec?1,and is superior to that of CoS(372 mV)and CeO2(530 mV)counterparts.And it has long-term durability under alkaline media. 相似文献
7.
Miaomiao Tong Lei Wang Peng Yu Xu Liu Honggang Fu 《Frontiers of Chemical Science and Engineering》2018,12(3):417-424
A highly active bi-functional electrocatalyst towards both hydrogen and oxygen evolution reactions is critical for the water splitting. Herein, a self-supported electrode composed of 3D network nanostructured NiCoP nanosheets grown on N-doped carbon coated Ni foam (NiCoP/NF@NC) has been synthesized by a hydrothermal route and a subsequent phosphorization process. As a bifunctional electrocatalyst, the NiCoP/NF@NC electrode needs overpotentials of 31.8 mV for hydrogen evolution reaction and 308.2 mV for oxygen evolution reaction to achieve the current density of 10 mA·cm−2 in 1 mol·L−1 KOH electrolyte. This is much better than the corresponding monometal catalysts of CoP/NF@NC and NiP/NF@NC owing to the synergistic effect. NiCoP/NF@NC also exhibits low Tafel slope, and excellent long-term stability, which are comparable to the commercial noble catalysts of Pt/C and RuO2. 相似文献
8.
为降低电解水阳极的析氧反应过电位,采用一步水热法制备了泡沫镍基钴铁混合氧化物(CoFe2O4@NF)复合材料。采用XRD、SEM、TEM和XPS等方法对复合材料进行表征,并利用三电极体系对其电解水析氧催化性能进行了测试。结果显示:CoFe2O4以颗粒的形式聚集成空心球结构生长于泡沫镍基底上,其中空心球的直径大约4 μm,而CoFe2O4的粒径约为40 nm左右。在1 mol·L-1 KOH溶液中,CoFe2O4@NF复合材料仅需293 mV的过电位即可达到20 mA·cm-2的电流密度,Tafel斜率为51 mV·dec-1。经过1 000次循环伏安扫描和10 h电流时间曲线测试后,其析氧性能依旧保持高稳定性,在析氧催化材料领域有着广阔的研究前景。 相似文献
9.
Meibo He Zhuang Liu Tong Li Chen Chen Baicang Liu John C.Crittenden 《Frontiers of Chemical Science and Engineering》2019,13(2):400-414
Thin-film composite (TFC) nanofiltration (NF) membranes were fabricated via the interfacial polymerization of piperazine (PIP) and 1,3,5-benzenetricart)oiiyl trichloride on polysulfone (PSf) support membranes blended with K^+-responsive poly(N-isopropylacryamideco- acryloylamidobenzo-15-crown-5)(P(NIPAM-co- AAB15C5)). Membranes were characterized by attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscope, scanning electron microscope, contact angle, and filtration tests. The results showed that:(1) Under K^+-free conditions, the blended P(NIPAM-co-AAB15C5)/PSf supports had porous and hydrophilic surfaces, thereby producing NF membranes with smooth surfaces and low MgSO4 rejections;(2) With K^+ in the PIP solution, the surface roughness and water permeability of the resultant NF membrane were increased due to the K^+-induced transition of low-content P(NIPAM-co-AAB15C5) from hydrophilic to hydrophobic;(3) After a curing treatment at 95℃, the improved NF membrane achieved an even higher pure water permeability of 10.97 L·m^-2·h^-1 - bar1 under 200 psi. Overall, this study provides a novel method to improve the performance of NF membranes and helps understand the influence of supports on TFC membranes. 相似文献
10.
Jie Lan Daizong Qi Jie Song Peng Liu Yi Liu Yun-Xiang Pan 《Frontiers of Chemical Science and Engineering》2020,14(6):948
Cobalt hydroxide has been emerging as a promising catalyst for the electrocatalytic oxidation reactions, including the oxygen evolution reaction (OER) and glucose oxidation reaction (GOR). Herein, we prepared cobalt hydroxide nanoparticles (CoHP) and cobalt hydroxide nanosheets (CoHS) on nickel foam. In the electrocatalytic OER, CoHS shows an overpotential of 306 mV at a current density of 10 mA·cm–2. This is enhanced as compared with that of CoHP (367 mV at 10 mA·cm–2). In addition, CoHS also exhibits an improved performance in the electrocatalytic GOR. The improved electrocatalytic performance of CoHS could be due to the higher ability of the two-dimensional nanosheets on CoHS in electron transfer. These results are useful for fabricating efficient catalysts for electrocatalytic oxidation reactions. 相似文献
11.
Zhe Yang Xiaoyu Huang Jianqiang Wang Chuyang Y. Tang 《Frontiers of Chemical Science and Engineering》2018,12(2):273-282
Most commercial NF membranes are negatively charged at the pH range of a typical feed solution. In order to enhance the removal of cations (such as Mg2+ or Ca2+), we utilized polyethyleneimine (PEI) and trimesoyl chloride (TMC) to perform interfacial polymerization reaction on a polydopamine coated hydrolyzed polyacrylonitrile substrate to obtain a positively charged nanofiltration membrane. Effects of polydopamine coating time, PEI concentration, TMC reaction time and concentration on the membrane physicochemical properties and separation performance were systematically investigated using scanning electron microscopy, streaming potential and water contact angle measurements. The optimal NF membrane showed high rejection for divalent ions (93.6±2.6% for MgSO4, 92.4±1.3% for MgCl2, and 90.4±2.1% for Na2SO4), accompanied with NaCl rejection of 27.8±2.5% with a permeation flux of 17.2±2.8 L·m−2·h−1 at an applied pressure of 8 bar (salt concentrations were all 1000 mg·L−1). The synthesized membranes showed promising potentials for the applications of water softening. 相似文献
12.
采用原位生长法,在泡沫镍(nickel foam,NF)基底上制备具有三维互连结构的CuGeO3纳米片,直接将CuGeO3/NF电极材料用作锂离子电池电极,省去了涂覆法制备粉末电极所需的高分子黏结剂。利用X射线衍射仪、X射线光电子能谱、扫描电镜和透射电镜分析了电极材料的结构和形貌,测试了CuGeO3/NF和CuGeO3两种负极材料的电化学性能。结果表明,与传统涂覆法制备的CuGeO3粉末电极相比,CuGeO3/NF无黏结剂型电极具有更好的循环性能和倍率性能。在0.2A/g电流密度下500次循环后,可逆比容量为972mA·h/g,容量保持率94.1%;在电流密度为1A/g时,可逆比容量为578mA·h/g,电流密度恢复至0.1A/g时,可逆比容量升高至936mA·h/g。CuGeO3/NF电极材料良好的电化学性能归因于泡沫镍的三维导电网络结构。此外,泡沫镍负载CuGeO3纳米片加快了嵌锂/脱锂过程中电子和离子的传输,缓解了活性物质的体积膨胀。 相似文献
13.
Xiqing Luo Miaomiao Jiang Kun Shi Zhangxian Chen Zeheng Yang Weixin Zhang 《Frontiers of Chemical Science and Engineering》2021,15(5):1322
For high performance supercapacitors, novel hierarchical yolk-shell a-Ni(OH)2/Mn2O3 microspheres were controllably synthesized using a facile two-step method based on the solvothermal treatment. The unique a-Ni(OH)2 based yolk-shell microstructures decorated with numerous interconnected nanosheets and the hetero-composition features can synergistically enhance reactive site exposure and electron conduction within the microspheres, facilitate charge transfer between electrolyte and electrode materials, and release structural stress during OH− chemisorption/desorption. Moreover, the Mn2O3 sediments distributed over the a-Ni(OH)2 microspheres can serve as an effective protective layer for electrochemical reactions. Consequently, when tested in 1 mol·L−1 KOH aqueous electrolyte for supercapacitors, the yolk-shell a-Ni(OH)2/Mn2O3 microspheres exhibited a considerably high specific capacitance of 2228.6 F·g−1 at 1 A·g−1 and an impressive capacitance retention of 77.7% after 3000 cycles at 10 A·g−1. The proposed a-Ni(OH)2/Mn2O3 microspheres with hetero-composition and unique hierarchical yolk-shell microstructures are highly promising to be used as electrode materials in supercapacitors and other energy storage devices. 相似文献
14.
Yunrui Tian Haishun Du Shatila Sarwar Wenjie Dong Yayun Zheng Shumin Wang Qingping Guo Jujie Luo Xinyu Zhang 《Frontiers of Chemical Science and Engineering》2021,15(4):1021-1032
We present a one-step route for the preparation of nickel phosphide/carbon nanotube (Ni2P@CNT) nanocomposites for supercapacitor applications using a facile, ultrafast (90 s) microwave-based approach. Ni2P nanoparticles could grow uniformly on the surface of CNTs under the optimized reaction conditions, namely, a feeding ratio of 30:50:25 for CNT, Ni(NO3)2·6H2O, and red phosphorus and a microwave power of 1000 W for 90 s. Our study demonstrated that the single-step microwave synthesis process for creating metal phosphide nanoparticles was faster and simpler than all the other existing methods. Electrochemical results showed that the specific capacitance of the optimal Ni2P@CNT-nanocomposite electrode displayed a high specific capacitance of 854 F·g−1 at 1 A·g−1 and a superior capacitance retention of 84% after 5000 cycles at 10 A·g−1. Finally, an asymmetric supercapacitor was assembled using the nanocomposite with activated carbon as one electrode (Ni2P@CNT//AC), which showed a remarkable energy density of 33.5 W·h·kg−1 and a power density of 387.5 W·kg−1. This work will pave the way for the microwave synthesis of other transition metal phosphide materials for use in energy storage systems. 相似文献
15.
Effective extraction of lithium from high Mg~(2+)/Li+ratio brine lakes is of great challenge. In this work, organic–inorganic hybrid silica nanofiltration(NF) membranes were prepared by dip-coating a 1,2-bis(triethoxysilyl)ethane(BTESE)-derived separation layer on tubular TiO_2 support, for efficient separation of LiC l and MgCl_2 salt solutions. We found that the membrane calcinated at 400 °C(M1–400) could exhibit a narrow pore size distribution(0.63–1.66 nm) owing to the dehydroxylation and the thermal degradation of the organic bridge groups. All as-prepared membranes exhibited higher rejections to LiCl than to MgCl_2, which was attributed to the negative charge of the membrane surfaces. The rejection for LiCl and MgCl_2 followed the order: LiCl N MgCl_2, revealing that Donnan exclusion effect dominated the salt rejection mechanism. In addition, the triplecoated membrane calcined at 400 °C(M3–400) exhibited a permeability of about 9.5 L·m~(-2)·h~(-1)·bar~(-1) for LiCl or MgCl_2 solutions, with rejections of 74.7% and 20.3% to LiCl and MgCl_2,respectively, under the transmembrane pressure at 6 bar. Compared with the previously reported performance of NF membranes for Mg~(2+)/Li+separation, the overall performance of M3–400 is highly competitive. Therefore, this work may provide new insight into designing robust silica-based ceramic NF membranes with negative charge for efficient lithium extraction from salt lakes. 相似文献
16.
Yiyi Fan Jinyong Li Saidi Wang Xiuxia Meng Yun Jin Naitao Yang Bo Meng Jiaquan Li Shaomin Liu 《Frontiers of Chemical Science and Engineering》2021,15(4):882
Hydrogen fuel has been embraced as a potential long-term solution to the growing demand for clean energy. A membrane-assisted separation is promising in producing high-purity H2. Molecular sieving membranes (MSMs) are endowed with high gas selectivity and permeability because their well-defined micropores can facilitate molecular exclusion, diffusion, and adsorption. In this work, MXene nanosheets intercalated with Ni2+ were assembled to form an MSM supported on Al2O3 hollow fiber via a vacuum-assisted filtration and drying process. The prepared membranes showed excellent H2/CO2 mixture separation performance at room temperature. Separation factor reached 615 with a hydrogen permeance of 8.35 × 10−8 mol·m−2·s−1·Pa−1. Compared with the original Ti3C2Tx/Al2O3 hollow fiber membranes, the permeation of hydrogen through the Ni2+-Ti3C2Tx/Al2O3 membrane was considerably increased, stemming from the strong interaction between the negatively charged MXene nanosheets and Ni2+. The interlayer spacing of MSMs was tuned by Ni2+. During 200-hour testing, the resultant membrane maintained an excellent gas separation without any substantial performance decline. Our results indicate that the Ni2+ tailored Ti3C2Tx/Al2O3 hollow fiber membranes can inspire promising industrial applications. 相似文献
17.
Simon Roussanaly Monika Vitvarova Rahul Anantharaman David Berstad Brede Hagen Jana Jakobsen Vaclav Novotny Geir Skaugen 《Frontiers of Chemical Science and Engineering》2020,14(3):436
This paper compares the techno-economic performances of three technologies for CO2 capture from a lignite-based IGCC power plant located in the Czech Republic: (1) Physical absorption with a Rectisol-based process; (2) Polymeric CO2-selective membrane-based capture; (3) Low-temperature capture. The evaluations show that the IGCC plant with CO2 capture leads to costs of electricity between 91 and 120 €·MWh−1, depending on the capture technology employed, compared to 65 €·MWh−1 for the power plant without capture. This results in CO2 avoidance costs ranging from 42 to 84 €·tCO2,avoided−1 , mainly linked to the losses in net power output. From both energy and cost points of view, the low-temperature and Rectisol based CO2 capture processes are the most efficient capture technologies. Furthermore, partial CO2 capture appears as a good mean to ensure early implementation due to the limited increase in CO2 avoidance cost when considering partial capture. To go beyond the two specific CO2-selective membranes considered, a cost/membrane property map for CO2-selective membranes was developed. This map emphasise the need to develop high performance membrane to compete with solvent technology. Finally, the cost of the whole CCS chain was estimated at 54 €·tCO2,avoided−1 once pipeline transport and storage are taken into consideration. 相似文献
18.
Two-dimensional (2D) MoS2 nanomaterials have been extensively studied due to their special structure and high theoretical capacity, but it is still a huge challenge to improve its cycle stability and achieve superior fast charge and discharge performance. Herein, a facile one-step hydrothermal method is proposed to synthetize an ordered and self-assembled MoS2 nanoflower (MoS2/C NF) with expanded interlayer spacing via embedding a carbon layer into the interlayer. The carbon layer in the MoS2 interlayer can speed the transfer of electrons, while the nanoflower structure promotes the ions transport and improves the structural stability during the charging/discharging process. Therefore, MoS2/C NF electrode exhibits exceptional rate performance (318.2 and 302.3 mA·h·g-1 at 5.0 and 10.0 A·g-1, respectively) and extraordinary cycle durability (98.8% retention after 300 cycles at a current density of 1.0 A·g-1). This work provides a simple and feasible method for constructing high-performance anode composites for sodium ion batteries with excellent cycle durability and fast charge/discharge ability. 相似文献
19.
针对甲基丙烯醛氧化酯化浆态床反应过程中颗粒催化剂易破碎、活性组分易流失等缺点,采用浸渍法在电沉积到泡沫镍合金表面的氧化铝-氧化镁涂层上负载活性组分,制备了PdxPby/Al2O3-MgO/泡沫镍合金整体式催化剂。研究分析了铝溶胶含量、Al2O3含量、沉积电压和沉积时间等条件对涂层负载的影响,并对载体和催化剂进行了BET、XRD、SEM、ICP和TEM表征和气-液-固固定床反应性能评价。结果表明,当铝溶胶的体积含量为35%~40%,Al2O3含量为25~30 g·L-1,沉积电压为10~12 V,沉积时间为8~12 min,搅拌速度为200~250 r·min-1时可得到稳定的涂层。在温度为80℃、压力为0.3 MPa、醇醛摩尔比为8:1、液相物料进口流量为0.5 ml·min-1、氧气进口流量为35 ml·min-1、反应时间为2 h条件下,整体式催化剂上甲基丙烯醛转化率最高为76.1%,甲基丙烯酸甲酯选择性为81.2%。研究结果可为甲基丙烯醛氧化酯化制甲基丙烯酸甲酯的生产工艺优化提供科学数据。 相似文献
20.
Huiying Quan Kejiang Qian Ying Xuan Lan-Lan Lou Kai Yu Shuangxi Liu 《Frontiers of Chemical Science and Engineering》2021,15(6):1561
It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction. However, achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging. In this study, we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO3 decorated with ZnxCd1−xS nanoparticles for hydrogen production under visible light irradiation (λ>420 nm). Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers. The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g−1·h−1, with an apparent quantum efficiency of 35.9% at 420 nm, which is 4.2 and 23.9 times higher than those of pure Zn0.5Cd0.5S (4.67 mmol·g−1·h−1) and CdS (0.82 mmol·g−1·h−1), respectively. In particular, under Pt-free conditions, an attractive hydrogen production rate (3.23 mmol·g−1·h−1) was achieved, providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting. Moreover, the composites showed excellent stability, and no obvious loss in activity was observed after five cycling tests. 相似文献