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排序方式: 共有818条查询结果,搜索用时 31 毫秒
1.
N. Clament Sagaya Selvam Lijie Du Bao Yu Xia Pil J. Yoo Bo You 《Advanced functional materials》2021,31(12):2008190
Electroreduction of small molecules such as H2O, CO2, and N2 for producing clean fuels or valuable chemicals provides a sustainable approach to meet the increasing global energy demands and to alleviate the concern on climate change resulting from fossil fuel consumption. On the path to implement this purpose, however, several scientific hurdles remain, one of which is the low energy efficiency due to the sluggish kinetics of the paired oxygen evolution reaction (OER). In response, it is highly desirable to synthesize high-performance and cost-effective OER electrocatalysts. Recent advances have witnessed surface reconstruction engineering as a salient tool to significantly improve the catalytic performance of OER electrocatalysts. In this review, recent progress on the reconstructed OER electrocatalysts and future opportunities are discussed. A brief introduction of the fundamentals of OER and the experimental approaches for generating and characterizing the reconstructed active sites in OER nanocatalysts are given first, followed by an expanded discussion of recent advances on the reconstructed OER electrocatalysts with improved activities, with a particular emphasis on understanding the correlation between surface dynamics and activities. Finally, a prospect for clean future energy communities harnessing surface reconstruction-promoted electrochemical water oxidation will be provided. 相似文献
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Di Suo Zhen Fang Yang-Yang Yu Yang-Chun Yong 《American Institute of Chemical Engineers》2020,66(4):e16897
Microbial electrocatalysis systems (MES) provide a cutting-edge solution to global problems associated with the environment and energy, but practical applications are hindered by the expensive electrode materials. Although stainless steel (SS) has been proposed as a promising inexpensive candidate, poor cell/SS interaction results in a low performance for MES. Here, a new synthetic biology approach was established for reinforcing the cell/SS interaction. Hybridized curli nanofibers fused with a metal-binding domain were heterogeneously expressed onto the cell surface, which realized efficient cell binding with the SS electrode. Consequently, it enabled a ~420-fold improvement of the anodic power output and a substantial enhancement of the cathodic Coulombic efficiency (from 0.6 to 4% to over 80%) with an SS electrode. This work demonstrates low-cost MES with an SS electrode and introduces a new avenue to engineer the cell/electrode interaction, which is promising for future practical applications of MES. 相似文献
5.
Abebe Reda Woldu Aamir Hassan Shah Haifeng Hu David Cahen Xuehua Zhang Tao He 《国际能源研究杂志》2020,44(1):548-559
Electrocatalytical conversion of CO2 into various chemicals like hydrocarbons and CO is regarded as a promising approach to mitigate carbon emission and, meanwhile, to provide sustainable energy and value-added chemicals. Two different reactors are used in this work. One is based upon the two-electrode configuration powered by a DC power supply or Si solar cell, which is suitable for practical applications. Another is three-electrode one powered by a potentiostat, which is feasible to study the electrode performance. Polycrystalline Cu electrode is used as the cathode, and hematite is the anode. Performance of CO2 reduction using the two- and three-electrode configurations is studied by measuring electrode potential, cell voltage, current density, Faradaic efficiency, and reduction selectivity of CO2. Cu cathode used here exhibits a low overpotential for CO2 reduction, specifically for the cell with two-electrode configuration. No obvious difference can be observed between the two types of configurations at a low bias like −0.3 and −0.4 V; while the reactor with two-electrode configuration exhibits better performance at a high bias like −0.8 V than the one with three-electrode configuration. Thus, the reactors with two-electrode configuration are desirable for practical applications, specifically considering solar cells can be used as the power source to provide green and sustainable energy. 相似文献
6.
Chidinma Judith Oluigbo Nabi Ullah Meng Xie Chukwuma Christian Okoye Bashir Adegbemiga Yusuf Waleed Yaseen Jagadeeh Kumar Alagarasan Kanagaraj Rajalakshmi Yuanguo Xu Jimin Xie 《国际能源研究杂志》2020,44(11):9157-9165
Cheap production of hydrogen (H2) from eco-friendly routes is preeminent for solving future energy challenges. This study explores the hydrogen evolution reaction (HER) activity of nickel (Ni) nanoparticles and nitrogen doped carbon nanotubes (NiNCNTs), which are fabricated by a cheap and one-step pyrolysis method. The most active catalyst synthesized at 800°C exhibits an overpotential of 0.244 V to reach a current density of 10 mA cm−2, Tafel slope of 93.3 mV dec−1 and a satisfactory 10 hours stability. Low resistance and large ECSA value of the sample also favor the competent response for HER in alkaline media. The robust HER activity of the catalyst is as a result of the nickel nanoparticles which are the active spots of reaction; while the presence of well-developed nitrogen containing carbon nanotubes with large content of pyridinic and graphitic nitrogen may provide high-electron density and feasible routes for its transportation to deliver an outstanding HER performance. 相似文献
7.
Engineering Morphologies of Cobalt Pyrophosphates Nanostructures toward Greatly Enhanced Electrocatalytic Performance of Oxygen Evolution Reaction 下载免费PDF全文
Herein, a surfactant‐ and additive‐free strategy is developed for morphology‐controllable synthesis of cobalt pyrophosphate (CoPPi) nanostructures by tuning the concentration and ratio of the precursor solutions of Na4P2O7 and Co(CH3COO)2. A series of CoPPi nanostructures including nanowires, nanobelts, nanoleaves, and nanorhombuses are prepared and exhibit very promising electrocatalytic properties toward the oxygen evolution reaction (OER). Acting as both reactant and pseudo‐surfactant, the existence of excess Na4P2O7 is essential to synthesize CoPPi nanostructures for unique morphologies. Among all CoPPi nanostructures, the CoPPi nanowires catalyst renders the best catalytic performance for OER in alkaline media, achieving a low Tafel slope of 54.1 mV dec−1, a small overpotential of 359 mV at 10 mA cm−2, and superior stability. The electrocatalytic activities of CoPPi nanowires outperform the most reported non‐noble metal based catalysts, even better than the benchmark Ir/C (20%) catalyst. The reported synthesis of CoPPi gives guidance for morphology control of transition metal pyrophosphate based nanostructures for a high‐performance inexpensive material to replace the noble metal‐based OER catalysts. 相似文献
8.
Liquid‐Phase Exfoliated Indium–Selenide Flakes and Their Application in Hydrogen Evolution Reaction 下载免费PDF全文
Single‐ and few‐layered InSe flakes are produced by the liquid‐phase exfoliation of β‐InSe single crystals in 2‐propanol, obtaining stable dispersions with a concentration as high as 0.11 g L−1. Ultracentrifugation is used to tune the morphology, i.e., the lateral size and thickness of the as‐produced InSe flakes. It is demonstrated that the obtained InSe flakes have maximum lateral sizes ranging from 30 nm to a few micrometers, and thicknesses ranging from 1 to 20 nm, with a maximum population centered at ≈5 nm, corresponding to 4 Se–In–In–Se quaternary layers. It is also shown that no formation of further InSe‐based compounds (such as In2Se3) or oxides occurs during the exfoliation process. The potential of these exfoliated‐InSe few‐layer flakes as a catalyst for the hydrogen evolution reaction (HER) is tested in hybrid single‐walled carbon nanotubes/InSe heterostructures. The dependence of the InSe flakes' morphologies, i.e., surface area and thickness, on the HER performances is highlighted, achieving the best efficiencies with small flakes offering predominant edge effects. The theoretical model unveils the origin of the catalytic efficiency of InSe flakes, and correlates the catalytic activity to the Se vacancies at the edge of the flakes. 相似文献
9.
Yuxing Yan Guangrui Chen Peihong She Guiyuan Zhong Wenfu Yan Bu Yuan Guan Yusuke Yamauchi 《Advanced materials (Deerfield Beach, Fla.)》2020,32(44):2004654
Mesoporous materials have attracted considerable attention because of their distinctive properties, including high surface areas, large pore sizes, tunable pore structures, controllable chemical compositions, and abundant forms of composite materials. During the last decade, there has been increasing research interest in constructing advanced mesoporous nanomaterials possessing short and open channels with efficient mass diffusion capability and rich accessible active sites for electrochemical energy conversion and storage. Here, the synthesis, structures, and energy-related applications of mesoporous nanomaterials are the main focus. After a brief summary of synthetic methods of mesoporous nanostructures, the delicate design and construction of mesoporous nanomaterials are described in detail through precise tailoring of the particle sizes, pore sizes, and nanostructures. Afterward, their applications as electrode materials for lithium-ion batteries, supercapacitors, water-splitting electrolyzers, and fuel cells are discussed. Finally, the possible development directions and challenges of mesoporous nanomaterials for electrochemical energy conversion and storage are proposed. 相似文献
10.
《International Journal of Hydrogen Energy》2021,46(59):30355-30365
To design inexpensive carbon catalysts and enhance their oxygen reduction reaction (ORR) activity is critical for developing efficient energy-conversion systems. In this work, a novel Fe-N-C hybrid electrocatalyst with carbon nanolayers-encapsulated Fe3O4 nanoparticles is synthesized successfully by utilizing the molecular-level confinement of graphitic C3N4 structures via hemin biomaterial. Benefiting from the Fe-N structure prevalent on the carbon nanosheets and large mesopore-dominated specific surface area, the synthesized catalyst under optimized conditions shows excellent electrocatalytic performance for ORR with an EORR at 1.08 V versus reversible hydrogen electrode (RHE) and an E1/2 at 0.87 V vs. RHE, and outstanding long-term stability, which is superior to commercial Pt/C catalysts (EORR at 1.04 V versus RHE and E1/2 at 0.84 V versus RHE). Moreover, the low hydrogen peroxide yield (<11%) and average electron transfer number (~3.8) indicate a four-electron ORR pathway. Besides, the maximum power density of the home-made Zn-air battery using the obtained catalyst is 97.6 mW cm−2. This work provides a practical route for the synthesis of cheap and efficient ORR electrocatalysts in metal-air battery systems. 相似文献