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1.
《International Journal of Hydrogen Energy》2021,46(78):38724-38732
Rational design of efficient oxygen evolution reaction (OER) electrocatalysts plays a significant role in various applications like water splitting and metal-air batteries. Simultaneous modulation of geometric and electronic structure is a promising strategy for boosting the electrocatalytic active of OER catalysts. Herein, a novel type of Mn doped Co9S8 supported on N-enriched porous carbon polyhedron composite material (Mn–Co9S8/NC) is constructed via absorption-pyrolysis-sulfurization treatment of Zeolitic-imidazolate frameworks (ZIF-67). ZIF-67 derived N-enriched porous carbon polyhedron serves as the porous skeleton for anchoring numerous Co9S8 nanoparticles. The results confirm that the incorporation of Mn in Co9S8/NC can improve the degree of graphitization compared with Co9S8/NC, implying the enhancement of the conductivity. Meanwhile, the incorporation of Mn can lead to electronic modulation of Co species to bump up the intrinsic activity of active site in Mn–Co9S8/NC. Due to the synergistic effect of Mn, Co9S8 and porous carbon structure, the specific surface area and electronic structure are optimized, endowing the maximum utilization of active sites. The Mn–Co9S8/NC electrocatalyst exhibits superior OER activity with the overpotential of 286 mV at current density of 10 mA cm−2 in 1.0 M KOH electrolyte. This work provides prospective insights into the synergistic coupling of geometric and electronic structure of Metal-Organic Frameworks (MOFs) material for efficient electrocatalysts. 相似文献
2.
《International Journal of Hydrogen Energy》2022,47(78):33308-33318
Rational design and synthesis of carbon nanostructures doped with atomically dispersed metal sites is an effective method to improve electrocatalytic oxygen reduction reaction (ORR) performance. Introducing mesopores into substrate carbon materials would help expose more active sites and improve mass/charge transfer in the microenvironments near active sites, thus accelerating ORR. Nonetheless, it is still challenging to construct atomically dispersed metal-nitrogen-carbon with mesoporous structures. Herein, we propose a facile strategy to synthesize atomically dispersed Fe-Nx sites doped mesopore-dominated carbon nanodisks catalysts (Fe–N/CNDs) using functionalized zeolitic imidazole frameworks (ZIF-D). The Fe–N/CNDs-900 catalyst exhibits outstanding ORR activity (Eo = 1.03 V, E1/2 = 850 mV), as well as excellent long-term durability and methanol-tolerance, ascribed to synergistic effect of the Fe-Nx active sites and the surrounding mesoporous structures. This work presents a promising method to develop highly efficient metal-nitrogen-carbon ORR catalysts using functionalized MOFs. 相似文献
3.
《International Journal of Hydrogen Energy》2020,45(23):12787-12797
The development of safe, cost-effective and efficient electrocatalyst is significant for oxygen evolution reaction (OER). Herein, cobalt nanoparticles embedded-nitrogen doped carbon composite (Co-NC) is prepared by pyrolysis of a Co based zeolitic imidazolate framework (ZIF-67) precursor, which is synthesized by KOH assisted deprotonation of 2-methylimidazole ligand and coordination with Co(Ac)2 in a safe ethanol medium. The alkali deprotonation and employment of Co(Ac)2 reactant obviously enhance the yield, phase purity and structural stability of the afforded ZIF-67 precursor (denoted as K-ZIF-67-Ac) and further the OER catalytic efficiency of the resultant Co-NC composite. The typical Co-NC catalyst prepared by carbonization of K-ZIF-67-Ac at 800 °C in N2 atmosphere, denoted as K-ZIF-67-Ac-800, displays obviously lower overpotential (350 mV) at current density of 50 mA cm−2, higher OER catalytic kinetics and robust durability over other ZIF-67 derived Co-NC catalysts. The current work paves a feasible avenue to prepare efficient Co-NC OER catalyst from alkali deprotonation assisted ZIF precursor. 相似文献
4.
《International Journal of Hydrogen Energy》2022,47(28):13616-13628
Transition metals sulfide-based nanomaterials have recently received significant attention as a promising cathode electrode for the oxygen evolution reaction (OER) due to their easily tunable electronic, chemical, and physical properties. However, the poor electrical conductivity of metal-sulfide materials impedes their practical application in energy devices. Herein, firstly nano-sized crystals of cobalt-based zeolitic-imidazolate framework (Co-ZIF) arrays were fabricated on nickel-form (NF) as the sacrificial template by a facile solution method to enhance the electrical conductivity of the electrocatalyst. Then, the Co3S4/NiS@NF heterostructured arrays were synthesized by a simple hydrothermal route. The Co-ZIFs derived Co3S4 nanosheets are grown successfully on NiS nanorods during the hydrothermal sulfurization process. The bimetallic sulfide-based Co3S4/NiS@NF-12 electrocatalyst demonstrated a very low overpotential of 119 mV at 10 mA cm?2 for OER, which is much lower than that of mono-metal sulfide NiS@NF (201 mV) and ruthenium-oxide (RuO2) on NF (440 mV) electrocatalysts. Furthermore, the Co3S4/NiS@NF-12 electrocatalyst showed high stability during cyclic voltammetry and chronoamperometry measurements. This research work offers an effective strategy for fabricating high-performance non-precious OER electrocatalysts. 相似文献
5.
《International Journal of Hydrogen Energy》2022,47(39):17367-17378
A non-precious metal electrocatalyst was obtained through the in-situ growth of iron phosphide (Fe2P) encapsulated by carbon nanotubes (CNTs) decorated with zeolitic imidazolate framework-8 (ZIF-8). Upon pyrolysis at a specific temperature, the ZIF-8/Fe2P@CNT catalyst exhibits high oxygen reduction reaction (ORR) ability and is close to the ideal electron transfer, which number is 3.99. The structure, high number of nitrogen-containing functional groups, and suitable surface properties of ZIF-8/Fe2P@CNT are critical for enhancing the ORR activity. ZIF-8/Fe2P@CNT exhibits a decay in electrocatalytic activity of 26 mV in the half-wave potential after 30 000 cycles, which is considerably superior to the decay of 123 mV for Pt/C after the same number of cycles. Therefore, ZIF-8/Fe2P@CNT exhibits excellent ORR activity and long-term stability and can be used as a fuel cell catalyst. 相似文献
6.
Jing-Qi Chi Kai-Li Yan Zi Xiao Bin Dong Xiao Shang Wen-Kun Gao Xiao Li Yong-Ming Chai Chen-Guang Liu 《International Journal of Hydrogen Energy》2017,42(32):20599-20607
Trimetallic NiFeCo selenides (NiFeCoSex) anchored on carbon fiber cloth (CFC) as efficient electrocatalyst for oxygen evolution reaction (OER) in alkaline medium have been synthesized via a facile two-step method. Firstly, trimetallic NiFeCo (oxy) hydroxides have been electrodeposited on CFC support (NiFeCo/CFC). Secondly, a solvothermal selenization process has been used to convert NiFeCo/CFC into NiFeCoSex/CFC using N, N-dimethylformamide (DMF) as solvent. The composition and homogeneous distribution of NiFeCoSex/CFC nanoparticles are determined by XRD, XPS, SEM elemental mapping and EDX images. Furthermore, SEM images reveal that NiFeCoSex/CFC has volcano-shaped morphology with rough surface and homogenously distributed on the surface of CFC, which may provide more active sites for OER. The electrochemical measurements show that trimetallic NiFeCoSex/CFC possesses the better electrocatalytic activity with the lower overpotential (150 mV at 10 mA cm?2), Tafel slope (85 mV dec?1), larger double-layer capacitance (200 mF cm?2) and long-term stability than unary or binary metal selenides. The enhanced activity of NiFeCoSex/CFC may be attributed to the trimetallic NiFeCo selenides and selenides-CFC synergistic interaction. It may offer a promising way to design transition multimetallic selenides supported on conductive support as electrocatalysts for OER. 相似文献
7.
Jing-Qi Chi Xiao Shang Wen-Kun Gao Bin Dong Kai-Li Yan Xiao Li Yan-Ru Liu Yong-Ming Chai Chen-Guang Liu 《International Journal of Hydrogen Energy》2017,42(22):15189-15195
Novel binary metal Fe0.5Co0.5Se2 spheres supported on carbon fiber cloth (CFC) as efficient electrocatalyst for oxygen evolution reaction (OER) have been successfully synthesized by a facile solvothermal selenization using N, N-dimethylformamide (DMF) as solvent. Firstly, Fe0.5Co0.5 nanosheets have been electrodeposited on the surface of CFC. Then, Fe0.5Co0.5/CFC as precursor has been converted to uniform Fe0.5Co0.5Se2 spheres on CFC (Fe0.5Co0.5Se2/CFC) by DMF selenization process. XRD and EDX confirm the typical crystalline structure and homogeneous elemental distribution of Fe0.5Co0.5Se2 on the surface of CFC. XPS shows the existence and valence of Fe, Co and Se. The uniform size and good dispersion of Fe0.5Co0.5Se2 spheres with the diameter of about 100 nm have been revealed by SEM and elemental mapping, which may provide more active sites for OER. The electrochemical results demonstrate that the obtained Fe0.5Co0.5Se2/CFC possesses the better OER activity with smaller overpotential, lower Tafel slope and charge transfer resistance than other samples, which may be ascribed to the uniform spherical morphology and the better intrinsic activity from binary metal Fe0.5Co0.5Se2. Moreover, the faster electron transfer rate derived from CFC support and the synergistic effect between Fe0.5Co0.5Se2 and CFC may be responsible for the enhancements of OER performances. 相似文献
8.
《International Journal of Hydrogen Energy》2020,45(41):21221-21231
Non-precious transition metal electrocatalysts with high catalytic performance and low cost enable the scalable and sustainable production of hydrogen energy through water splitting. In this work, based on the polymerization of CoMoO4 nanorods and pyrrole monomer, a heterointerface of carbon-wrapped and Co/Mo2C composites are obtained by thermal pyrolysis method. Co/Mo2C composites show considerable performance for both hydrogen and oxygen evolution in alkaline media. In alkaline media, Co/Mo2C composites show a small overpotential, low Tafel slope, and excellent stability for water splitting. Co/Mo2C exhibits a small overpotential of 157 mV for hydrogen evolution reaction and 366 mV for oxygen evolution reaction at current density of 10 mA cm−2, as well as a low Tafel slope of 109.2 mV dec−1 and 59.1 mV dec−1 for hydrogen evolution reaction and oxygen evolution reaction, respectively. Co/Mo2C composites also exhibit an excellent stability, retaining 94% and 93% of initial current value for hydrogen evolution reaction and oxygen evolution reaction after 45,000 s, respectively. Overall water splitting via two-electrode water indicates Co/Mo2C can hold 91% of its initial current after 40,000 s in 1 M KOH. 相似文献
9.
Yisi Liu Haibo Shen Hao Jiang Wenzhang Li Jie Li Yaomin Li Yang Guo 《International Journal of Hydrogen Energy》2017,42(18):12978-12988
Development of efficient electrocatalysts for the oxygen reduction reaction (ORR) is vitally important for the commercialization of metal–air batteries. In this work, we demonstrate a novel graphene coated/Co9S8 nanoparticles-embedded nitrogen doped porous carbon dodecahedron hybrid (Co9S8/NPCP@rGO) prepared by the pyrolysis and sulphuration of precursors composing of graphene oxide and zeolitic imidazolate-frameworks (ZIF). The Co9S8/NPCP@rGO hybrid is used as a highly efficient nonprecious metal electrocatalyst for oxygen reduction and exhibits more positive onset potential and half-wave potential, higher limiting current density, lower Tafel slope, and better durability and methanol tolerance in alkaline media in comparison to the commercial 20 wt.% Pt/C catalyst. The greatly improved electrocatalytic performance of Co9S8/NPCP@rGO can be attributed to the unique structure with Co9S8 nanoparticles dispersed uniformly inside nitrogen doped porous carbon matrix, and the synergistic effect between Co9S8/NPCP polyhedral hybrid and rGO. 相似文献
10.
《International Journal of Hydrogen Energy》2022,47(5):2958-2966
Exploring cost-efficient electrocatalysts for oxygen evolution reaction (OER) is still a huge challenge in the electrochemical energy conversion technology. In this work, Gallium (Ga)-doped Ni3S2 nanosheet arrays grown on Ti3C2-MXene/nickel foam (Ga–Ni3S2/Ti3C2/NF) have been synthesized by a successive hydrothermal and sulfidization process. The Ga doping modulates the electronic structure of Ni3S2, so tuning the adsorption energies of oxygen intermediate (1OOH). The Ga–Ni3S2/Ti3C2/NF delivers outstanding catalytic activities toward OER with an overpotential of 340 mV at 100 mA cm?2, and exhibits superior electrochemical durability. The excellent OER performance of Ga–Ni3S2/Ti3C2/NF can be ascribed to the 3D sheet arrays morphology and optimized electronic structure. Density functional theory (DFT) calculations also demonstrate that electronic disturbance attributed to Ga doping effectively improves the activity of Ni sites, leading to stronger binding strength of 1OOH intermediate at Ni sites nearby Ga. This study provides insights into the fabrication of advanced electrocatalysts for application. 相似文献
11.
《International Journal of Hydrogen Energy》2014,39(35):20662-20670
Ni oxide based nanoparticles (NPs) have been widely used as electrocatalysts in the electrochemical energy storage and conversion applications. In this paper, NiOx NPs are successfully synthesized by the self-assembly of Ni precursor onto polyethylenimine functionalized carbon nanotubes (PEI-CNTs) assisted with microwave radiation. NiOx NPs with size around 2–3 nm are homogenously dispersed on the PEI-CNTs supports with no aggregation. The electrochemical activity of NiOx NPs on PEI-CNTs, NiOx/PEI-CNTs, as effective electrocatalysts is studied for supercapacitor and oxygen evolution reaction in alkaline solutions. NiOx/PEI-CNTs show a capacitance of 1728 and 1576 F g−1 based on active material, and 221 and 394 F g−1 based on total catalyst loading on 12.5% and 25% NiOx/PEI-CNTs, respectively, which is substantially higher than 152 F g−1 of unsupported NiO. The NiOx/PEI-CNTs electrodes exhibit reversible and stale capacitance of ∼1200 F g−1 based on active materials after 2000 cycles at a high current density of 10 A g−1. NiOx/PEI-CNTs also exhibit significantly higher activities for oxygen evolution reaction (OER) of water electrolysis, achieving a current density of 100 A g−1 at an overpotential of 0.35 V for 25% NiOx/PEI-CNTs. It is believed that the uniformly dispersed nano-sized NiOx NPs and synergistic effect between the NiOx NPs and PEI-CNTs is attributed to the high electrocatalytic performance of NiOx/PEI-CNTs electrocatalysts. The results demonstrate that NiOx NPs supported on PEI-CNTs are highly effective electrocatalysts for electrochemical energy storage and conversion applications. 相似文献
12.
《International Journal of Hydrogen Energy》2023,48(57):21723-21734
The design of hybrid electrocatalysts with abundant active sites and long term stability is crucial for efficient oxygen evolution reaction (OER) application. Cobalt oxide is considered as one of the most promising electrocatalysts to replace noble metal due to its low cost, availability, and electrocatalytic activity towards the oxygen evolution reaction in alkaline media. However, nano-scale cobalt oxide suffers from severe surface self-agglomeration during the OER process, so that leading to poor activity and durability. Herein, ultra-small cobalt oxide nanoparticles are anchored on the surface of nitrogen doped porous 3D graphitic carbon nano-spheres (N-ACS@Co3O4) to increase the amount of exposed active site and avoid the self-agglomeration. The obtained electrocatalyst (N-ACS@Co3O4) is enriched with abundant oxygen vacancies and exhibits a superior OER activity (Overpotential of 237 mV at 10 mA.cm−2) and exceptional stability for at least 30 h in alkaline electrolyte (1 M KOH). The DFT calculations demonstrate that the strong adsorption of Co3O4 on N-doped graphene can prevent its agglomeration, and therefore improves the stability of Co3O4 nanoparticles during OER process in line with the experimental results. 相似文献
13.
Weiwei Bao Lei Xiao Junjun Zhang Peng Jiang Xiangyu Zou Chunming Yang Xiaoli Hao Taotao Ai 《International Journal of Hydrogen Energy》2021,46(17):10259-10267
The oxygen evolution reaction (OER) involves four electron transfer processes and is of great significance in water electrolysis. The development of efficient and robust non-precious OER electrocatalysts remains a critical challenge for the production, storage and conversion of renewable energy. Herein, vertically NiCo2O4 nanosheets are grown on Ti mesh via a facile solvothermal method which is followed by low-temperature calcination. The NiCo2O4/Ti catalyst exhibits outstanding OER performance with a low overpotential of 353 mV to drive the current density of 10 mA cm?2 and a Tafel slope of 61 mV dec?1 in alkaline solution. Moreover, the stable electrocatalyst undergoes negligible degradation in alkaline media at least 20 h. The acceleration of the electrochemical OER likely stems from the facile electron transfer promoted by the NiCo2O4/Ti interface as revealed by X-ray photoelectron spectroscopy. This work introduces a novel strategy for the establishment low-cost electrocatalysts for electrochemical water splitting. 相似文献
14.
《International Journal of Hydrogen Energy》2023,48(33):12176-12184
Electrochemical water splitting is considered as a promising strategy for the efficient hydrogen production, yet it is hindered by the sluggish oxygen evolution reaction (OER). Herein, heterostructure OER catalyst is fabricated by combining MoS2 nanosheets with NiCo2O4 hollow sphere on Ti mesh. Benefiting from the heterogeneous nanointerface between NiCo2O4 and MoS2, this electrocatalyst demonstrates excellent OER activity in basic environment with overpotentials of 313 and 380 mV achieving 10 and 100 mA cm−2. The superb catalytic performance stems from hollow the nanostructure and interfacial engineering strategy that enhance intrinsic activity and provide faster charge transfer. Hence, this work provides a feasible path for exploiting the high-efficient catalysts. 相似文献
15.
《International Journal of Hydrogen Energy》2023,48(21):7698-7707
Here, a dual functional Nb2CTx@Pt nanocomposite has been synthesized by in situ reduction method. The Pt loading in the composite has been optimized to get minimum overpotential (141 mV at 10 mA/cm2) for hydrogen evolution reaction (HER) along with a promising Tafel slope of 46.3 mV/dec, while Pt/C shows an overpotential and Tafel slope of 104 mV and 32.4 mV/dec, respectively. The Pt mass activity for Nb2CTx@Pt3.8 composite at 100 mV overpotential was 3.44 A g?1 while the Pt mass activity for conventional Pt/C was 0.7 A g?1, which shows that the activity of Nb2CTx@Pt3.8 composite is approximately 5 times higher than Pt/C. In addition, the catalyst was found to be stable for continuous 500 cycles without any binder molecules. The oxygen reduction reaction (ORR) capability of the material was also evaluated and found that the catalyst exhibited a current density of ?4.28 mA/cm2 in the diffusion limiting region in comparison with the current density of ?5.82 mA/cm2 for Pt/C at 2600 revolutions per minute (RPM). The Pt mass activity of Nb2CTx@Pt3.8 composite for ORR is approximately 10 times higher than Pt/C. The Nb2CTx@Pt3.8 composite was able to reduce O2 completely using the 4-electron pathway with very little peroxide production. From these results, the dual functionality of the Nb2CTx@Pt3.8 composite for both HER and ORR has been established. 相似文献
16.
Zhou Yu Yu Bai Shimin Zhang Yuxuan Liu Naiqing Zhang Kening Sun 《International Journal of Hydrogen Energy》2018,43(18):8815-8823
The development of efficient, universal and cheap electrocatalysts for the utilization in the oxygen evolution reaction (OER) by desired morphology and composition remains a great challenge. Herein, we report a facile and novel method to prepare the porous hollow nickel-cobalt sulfide (NiCoS) by using zeolitic imidazolate framework-67 (ZIF-67) as the template. The obtained NiCoS-3 polyhedron shows superior catalytic activity toward OER with a low overpotential of 320 mV at the current density of 10 mA cm?2, a small Tafel slope of 58.8 mV dec?1 and excellent stability. Benefiting from their structural and compositional merits, the as-synthesized NiCoS-3 polyhedron may be a good promising candidate electrocatalysts for water splitting. Present work provides a simple strategy to regulated composition, morphology and catalytic activity relationship, offer an effective way to design a low-cost and efficient electrocatalyst. 相似文献
17.
Huijuan Han Shujun Chao Xiaoli Yang Xiaobing Wang Kui Wang Zhengyu Bai Lin Yang 《International Journal of Hydrogen Energy》2017,42(25):16149-16156
Recently, to improve the catalytic activity of oxygen evolution reaction (OER) electrocatalysts, some design strategies, such as the decrease of the catalyst particle size, the formation of the porous structure and the couple of carbon-based materials, are receiving increased attention in energy-related systems. Herein, based on metal organic framework (MOF), we develop an effective strategy to synthesize Ni nanoparticles embedded in N doped carbon nanotubes (Ni NPs@N-CNTs) catalyst. In consequence, the Ni NPs@N-CNTs integrates the advantageous features of NPs and N-CNTs towards OER, such as more catalytic sites, large surface area, pore-rich structure and good electrical conductivity. Benefiting from the favorable features, the Ni NPs@N-CNTs exhibits a better OER performance than commercial RuO2 in alkaline medium, which includes a lower onset potential (1.49 V), a smaller Tafel slope (106 mV dec?1). The present work opens a new window for the construction of the coupling materials between NPs and carbon-based materials to increase the electrocatalytic activity of transition metal catalysts. 相似文献
18.
《International Journal of Hydrogen Energy》2023,48(23):8489-8498
Traditional fossil fuels can be replaced with hydrogen, and electrolysis of water is thought to be one of the most efficient ways to produce hydrogen that is also pollution-free. The oxygen evolution reaction (OER), which is thought to be the bottleneck of the entire water decomposition, is a result of the intricate electrochemical mechanism and the slow kinetic process. In this paper, Cu(OH)2 forerunners with nanorods structure were combined on copper froth by straightforward submersion technique. Then, in a standard three-electrode system Fe7S8 and Co9S8 nanosheets with 3D structures were assembled on Cu(OH)2 precursors by electrodeposition. At an alkaline environment of 1 M KOH, Cu(OH)2/CF requires an overpotential of only 235 mV when the current density reaches 10 mA cm?2, which is lower than that of other reported catalysts. In addition, Fe7S8–Co9S8@Cu(OH)2/CF also showed excellent OER performance after long-term stability test, because bimetallic synergism can adjust the electronic structure of the catalyst and optimize its electrical conductivity. A feasible method for the design of a highly efficient oxygen evolution catalyst based on copper foam is reported in this paper. 相似文献
19.
《International Journal of Hydrogen Energy》2019,44(51):27806-27815
Highly active and stable catalysts towards electrochemical oxygen evolution reaction are crucial for efficient water splitting and sustainable hydrogen generation. Here we report a carbon supported FeNi catalyst synthesized from an in situ freeze-drying method (fd-FeNi/C) with a commonly seen biomass, jasminum mesnyi flower. The fd-FeNi/C exhibits a N-doped hierarchically mesoporous carbon structure decorated with small FeNi nanoparticles with a small diameter of ∼ 4 nm. Electrochemical measurements show excellent catalytic performance in 1 M KOH solution with an overpotential of 301 mV at the current density of 10 mA cm−2. The value is 41 mV lower than that of the commercial IrO2/C. A small Tafel slope (64.5 mV dec−1) and high stability are also recorded. This work provides a facile, scalable, and template-free approach to convert biomass into highly active electrochemical catalysts, which shows great potential for future applications. 相似文献
20.
《International Journal of Hydrogen Energy》2022,47(6):3834-3845
Significant progress has been made in recent time to design and synthesize highly efficient and cost effective electrocatalysts for oxygen evolution reaction (OER). However, the electrocatalytic activity of most recently reported materials is limited by the large onset potential, poor electrical conductivity and low density of catalytic centers. In this study, we report facile deposition of palladium oxide nanoparticles onto cobalt oxide nanostructures (PdONPs@Co3O4) through the illumination of ultraviolet (UV) light. The fabricated PdONPs@Co3O4 nanocomposites offer high density of active sites, improved electrical conductivity and durability for OER activity. The synergetic effect between the Co and Pd ions at the interface of composite system might change the adsorption energy of reaction intermediates, thus enabled the reaction to proceed at lower energy consumption. Significantly, the prepared PdONPs@Co3O4 samples demonstrated a low overpotential of 250 mV at a current density of 20 mA/cm2, with low charge transfer resistant of 48.5 Ωand high durability for more than 40 h during OER processes. The combined results suggest that incorporating of a low amount of PdONPs can tune the surface properties of Co3O4 and interfacial chemistry. This could led to accelerate the charge transport properties at the interface during a specific electrochemical application. 相似文献