共查询到20条相似文献,搜索用时 15 毫秒
1.
Qing Shi Qiao Liu Yu Ma Zhi Fang Zhao Liang Gang Shao Bin Tang Weiyou Yang Lin Qin Xiaosheng Fang 《Liver Transplantation》2020,10(10)
Currently, it is still a significant challenge to simultaneously boost various reactions by one electrocatalyst with high activity, excellent durability, as well as low cost. Herein, hybrid trifunctional electrocatalysts are explored via a facile one‐pot strategy toward an efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The catalysts are rationally designed to be composed by FeCo nanoparticles encapsuled in graphitic carbon films, Co2P nanoparticles, and N,P‐codoped carbon nanofiber networks. The FeCo nanoparticles and the synergistic effect from Co2P and FeCo nanoparticles make the dominant contributions to the ORR, OER, and HER activities, respectively. Their bifunctional activity parameter (?E) for ORR and OER is low to 0.77 V, which is much smaller than those of most nonprecious metal catalysts ever reported, and comparable with state‐of‐the‐art Pt/C and RuO2 (0.78 V). Accordingly, the as‐assembled Zn–air battery exhibits a high power density of 154 mW cm?2 with a low charge–discharge voltage gap of 0.83 V (at 10 mA cm?2) and excellent stability. The as‐constructed overall water‐splitting cell achieves a current density of 10 mA cm?2 (at 1.68 V), which is comparable to the best reported trifunctional catalysts. 相似文献
2.
Siraj Sultan Jitendra N. Tiwari Aditya Narayan Singh Shynggys Zhumagali Miran Ha Chang Woo Myung Pandiarajan Thangavel Kwang S. Kim 《Liver Transplantation》2019,9(22)
The sustainable and scalable production of hydrogen through hydrogen evolution reaction (HER) and oxygen through oxygen evolution reaction (OER) in water splitting demands efficient and robust electrocatalysts. Currently, state‐of‐the‐art electrocatalysts of Pt and IrO2/RuO2 exhibit the benchmark catalytic activity toward HER and OER, respectively. However, expanding their practical application is hindered by their exorbitant price and scarcity. Therefore, the development of alternative effective electrocatalysts for water splitting is crucial. In the last few decades, substantial effort has been devoted to the development of alternative HER/OER and water splitting catalysts based on various transition metals (including Fe, Co, Ni, Mo, and atomic Pt) which show promising catalytic activities and durability. In this review, after a brief introduction and basic mechanism of HER/OER, the authors systematically discuss the recent progress in design, synthesis, and application of single atom and cluster‐based HER/OER and water splitting catalysts. Moreover, the crucial factors that can tune the activity of catalysts toward HER/OER and water splitting such as morphology, crystal defects, hybridization of metals with nonmetals, heteroatom doping, alloying, and formation of metals inside graphitic layered materials are discussed. Finally, the existing challenges and future perspectives for improving the performance of electrocatalysts for water splitting are addressed. 相似文献
3.
Yinlong Zhu Wei Zhou Yijun Zhong Yunfei Bu Xiaoyang Chen Qin Zhong Meilin Liu Zongping Shao 《Liver Transplantation》2017,7(8)
The development of highly efficient and low‐cost electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is paramount for water splitting associated with the storage of clean and renewable energy. Here, this study reports its findings in the development of a nanostructured perovskite oxide as OER/HER bifunctional electrocatalyst for overall water splitting. Prepared by a facile electrospinning method, SrNb0.1Co0.7Fe0.2O3–δ perovskite nanorods (SNCF‐NRs) display excellent OER and HER activity and stability in an alkaline solution, benefiting from the catalytic nature of perovskites and unique structural features. More importantly, the SNCF‐NR delivers a current density of 10 mA cm?2 at a cell voltage of merely ≈1.68 V while maintaining remarkable durability when used as both anodic and cathodic catalysts in an alkaline water electrolyzer. The performance of this bifunctional perovskite material is among the best ever reported for overall water splitting, offering a cost‐effective alternative to noble metal based electrocatalysts. 相似文献
4.
Ziliang Chen Yuan Ha Huaxian Jia Xiaoxiao Yan Mao Chen Miao Liu Renbing Wu 《Liver Transplantation》2019,9(19)
Construction of well‐defined metal–organic framework precursor is vital to derive highly efficient transition metal–carbon‐based electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting. Herein, a novel strategy involving an in situ transformation of ultrathin cobalt layered double hydroxide into 2D cobalt zeolitic imidazolate framework (ZIF‐67) nanosheets grafted with 3D ZIF‐67 polyhedra supported on the surface of carbon cloth (2D/3D ZIF‐67@CC) precursor is proposed. After a low‐temperature pyrolysis, this precursor can be further converted into hybrid composites composed of ultrafine cobalt nanoparticles embedded within 2D N‐doped carbon nanosheets and 3D N‐doped hollow carbon polyhedra (Co@N‐CS/N‐HCP@CC). Experimental and density functional theory calculations results indicate that such composites have the advantages of a large number of accessible active sites, accelerated charge/mass transfer ability, the synergistic effect of components as well as an optimal water adsorption energy change. As a result, the obtained Co@N‐CS/N‐HCP@CC catalyst requires overpotentials of only 66 and 248 mV to reach a current density of 10 mA cm?2 for HER and OER in 1.0 m KOH, respectively. Remarkably, it enables an alkali‐electrolyzer with a current density of 10 mA cm?2 at a low cell voltage of 1.545 V, superior to that of the IrO2@CC||Pt/C@CC couple (1.592 V). 相似文献
5.
Developing highly efficient, cost effective, and environmentally friendly electrocatalysts for the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) is of interest for sustainable and clean energy technologies, including metal–air batteries and fuel cells. In this work, the screening of electrocatalytic activities of a series of single metallic iron, cobalt, and nickel nanoparticles and their binary and ternary alloys encapsulated in a graphitic carbon shell toward the OER, ORR, and HER in alkaline media is reported. Synthesis of these compounds proceeds by a two‐step sol–gel and carbothermal reduction procedure. Various ex situ characterizations show that with harsh electrochemical activation, the graphitic shell undergoes an electrochemical exfoliation. The modified electronic properties of the remaining graphene layers prevent their exfoliation, protect the bulk of the metallic cores, and participate in the electrocatalysis. The amount of near‐surface, higher‐oxidation‐state metals in the as‐prepared samples increases with electrochemical cycling, indicating that some metallic nanoparticles are not adequately encased within the graphite shell. Such surface oxide species provide secondary active sites for the electrocatalytic activities. The Ni–Fe binary system gives the most promising results for the OER, and the Co–Fe binary system shows the most promise for the ORR and HER. 相似文献
6.
Multifunctional Single‐Crystallized Carbonate Hydroxides as Highly Efficient Electrocatalyst for Full Water splitting
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The controllable synthesis of single‐crystallized iron‐cobalt carbonate hydroxide nanosheets array on 3D conductive Ni foam (FCCH/NF) as a monolithic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) bifunctional electrocatalyst for full water splitting is described. The results demonstrate that the incorporation of Fe can effectively tune the morphology, composition, electronic structure, and electrochemical active surface area of the electrocatalysts, thus greatly enhancing the intrinsic electrocatalytic activity. The optimal electrocatalyst (F0.25C1CH/NF) can deliver 10 and 1000 mA cm?2 at very small overpotentials of 77 and 256 mV for HER and 228 and 308 mV for OER in 1.0 m KOH without significant interference from gas evolution. The F0.25C1CH‐based two‐electrode alkaline water electrolyzer only requires cell voltages of 1.45 and 1.52 V to achieve current densities of 10 and 500 mA cm?2. The results demonstrate that such fascinating electrocatalytic activity can be ascribed to the increase in the catalytic active surface area, facilitated electron and mass transport properties, and the synergistic interactions because of the incorporation of Fe. 相似文献
7.
Xu Luo Pengxia Ji Pengyan Wang Ruilin Cheng Ding Chen Can Lin Jianan Zhang Jianwei He Zuhao Shi Neng Li Shengqiang Xiao Shichun Mu 《Liver Transplantation》2020,10(17)
Rational design and construction of bifunctional electrocatalysts with excellent activity and durability is imperative for water splitting. Herein, a novel top‐down strategy to realize a hierarchical branched Mo‐doped sulfide/phosphide heterostructure (Mo‐Ni3S2/NixPy hollow nanorods), by partially phosphating Mo‐Ni3S2/NF flower clusters, is proposed. Benefitting from the optimized electronic structure configuration, hierarchical branched hollow nanorod structure, and abundant heterogeneous interfaces, the as‐obtained multisite Mo‐Ni3S2/NixPy/NF electrode has remarkable stability and bifunctional electrocatalytic activity in the hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) in 1 m KOH solutions. It possesses an extremely low overpotential of 238 mV at the current density of 50 mA cm?2 for OER. Importantly, when assembled as anode and cathode simultaneously, it merely requires an ultralow cell voltage of 1.46 V to achieve the current density of 10 mA cm?2, with excellent durability for over 72 h, outperforming most of the reported Ni‐based bifunctional materials. Density functional theory results further confirm that the doped heterostructure can synergistically optimize Gibbs free energies of H and O‐containing intermediates (OH*, O*, and OOH*) during HER and OER processes, thus accelerating the catalytic kinetics of electrochemical water splitting. This work demonstrates the importance of the rational combination of metal doping and interface engineering for advanced catalytic materials. 相似文献
8.
Ding Chen Zonghua Pu Ruihu Lu Pengxia Ji Pengyan Wang Jiawei Zhu Can Lin Hai‐Wen Li Xiangang Zhou Zhiyi Hu Fanjie Xia Jingsong Wu Shichun Mu 《Liver Transplantation》2020,10(28)
Water splitting is a promising technology for sustainable conversion of hydrogen energy. The rational design of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) bifunctional electrocatalysts with superior activity and stability in the same electrolyte is the key to promoting their large‐scale applications. Herein, an ultralow Ru (1.08 wt%) transition metal phosphide on nickel foam (Ru–MnFeP/NF) derived from Prussian blue analogue, that effectively drivies both the OER and the HER in 1 m KOH, is reported. To reach 20 mA cm?2 for OER and 10 mA cm?2 for HER, the Ru–MnFeP/NF electrode only requires overpotentials of 191 and 35 mV, respectively. Such high electrocatalytic activity exceeds most transition metal phosphides for the OER and the HER, and even reaches Pt‐like HER electrocatalytic levels. Accordingly, it significantly accelerates full water splitting at 10 mA cm?2 with 1.470 V, which outperforms that of the integrated RuO2 and Pt/C couple electrode (1.560 V). In addition, the extremely long operational stability (50 h) and the successful demonstration of a solar‐to‐hydrogen generation system through full water splitting provide more flexibility for large‐scale applications of Ru–MnFeP/NF catalysts. 相似文献
9.
Electrocatalytic Oxygen Evolution Reaction in Acidic Environments – Reaction Mechanisms and Catalysts
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tobias Reier Hong Nhan Nong Detre Teschner Robert Schlögl Peter Strasser 《Liver Transplantation》2017,7(1)
The low efficiency of the electrocatalytic oxidation of water to O2 (oxygen evolution reaction‐OER) is considered as one of the major roadblocks for the storage of electricity from renewable sources in form of molecular fuels like H2 or hydrocarbons. Especially in acidic environments, compatible with the powerful proton exchange membrane (PEM), an earth‐abundant OER catalyst that combines high activity and high stability is still unknown. Current PEM‐compatible OER catalysts still rely mostly on Ir and/or Ru as active components, which are both very scarce elements of the platinum group. Hence, the Ir and/or Ru amount in OER catalysts has to be strictly minimized. Unfortunately, the OER mechanism, which is the most powerful tool for OER catalyst optimization, still remains unclear. In this review, we first summarize the current state of our understanding of the OER mechanism on PEM‐compatible heterogeneous electrocatalysts, before we compare and contrast that to the OER mechanism on homogenous catalysts. Thereafter, an overview over monometallic OER catalysts is provided to obtain insights into structure‐function relations followed by a review of current material optimization concepts and support materials. Moreover, missing links required to complete the mechanistic picture as well as the most promising material optimization concepts are pointed out. 相似文献
10.
Bimetallic Zeolitic Imidazolite Framework Derived Carbon Nanotubes Embedded with Co Nanoparticles for Efficient Bifunctional Oxygen Electrocatalyst
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yinle Li Baoming Jia Yanzhong Fan Kelong Zhu Guangqin Li Cheng‐Yong Su 《Liver Transplantation》2018,8(9)
Bifunctional oxygen catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high activities and low‐cost are of prime importance and challenging in the development of fuel cells and rechargeable metal–air batteries. This study reports a porous carbon nanomaterial loaded with cobalt nanoparticles (Co@NC‐x/y) derived from pyrolysis of a Co/Zn bimetallic zeolitic imidazolite framework, which exhibits incredibly high activity as bifunctional oxygen catalysts. For instance, the optimal catalyst of Co@NC‐3/1 has the interconnected framework structure between porous carbon and embedded carbon nanotubes, which shows the superb ORR activity with onset potential of ≈1.15 V and half‐wave potential of ≈0.93 V. Moreover, it presents high OER activity that can be further enhanced to over commercial RuO2 by P‐doped with overpotentials of 1.57 V versus reversible hydrogen electrode at 10 mA cm?2 and long‐term stability for 2000 circles and a Tafel slope of 85 mV dec?1. Significantly, the nanomaterial demonstrates better catalytic performance and durability than Pt/C for ORR and commercial RuO2 and IrO2 for OER. These findings suggest the importance of a synergistic effect of graphitic carbon, nanotubes, exposed Co–Nx active sites, and interconnected framework structure of various carbons for bifunctional oxygen electrocatalysts. 相似文献
11.
Jin Goo Lee Jae‐Ha Myung Aaron B. Naden Ok Sung Jeon Yong Gun Shul John T. S. Irvine 《Liver Transplantation》2020,10(10)
For efficient catalysis and electrocatalysis well‐designed, high‐surface‐area support architectures covered with highly dispersed metal nanoparticles with good catalyst‐support interactions are required. In situ grown Ni nanoparticles on perovskites have been recently reported to enhance catalytic activities in high‐temperature systems such as solid oxide cells (SOCs). However, the micrometer‐scale primary particles prepared by conventional solid‐state reactions have limited surface area and tend to retain much of the active catalytic element within the bulk, limiting efficacy of such exsolution processes in low‐temperature systems. Here, a new, highly efficient, solvothermal route is demonstrated to exsolution from smaller scale primary particles. Furthermore, unlike previous reports of B‐site exsolution, it seems that the metal nanoparticles are exsolved from the A‐site of these perovskites. The catalysts show large active site areas and strong metal‐support interaction (SMSI), leading to ≈26% higher geometric activity (25 times higher mass activity with 1.4 V of Eon‐set) and stability for oxygen‐evolution reaction (OER) with only 0.72 µg base metal contents compared to typical 20 wt% Ni/C and even commercial 20 wt% Ir/C. The findings obtained here demonstrate the potential design and development of heterogeneous catalysts in various low‐temperature electrochemical systems including alkaline fuel cells and metal–air batteries. 相似文献
12.
Jiawei Zhu Minghao Xie Zitao Chen Zhiheng Lyu Miaofang Chi Wanqin Jin Younan Xia 《Liver Transplantation》2020,10(16)
The development of dual catalysts with high efficiency toward oxygen reduction and evolution reactions (ORR and OER) in acidic media is a significant challenge. Here an active and durable dual catalyst based upon cubic Pt39Ir10Pd11 nanocages with an average edge length of 12.3 nm, porous walls as thin as 1.0 nm, and well‐defined {100} facets is reported. The trimetallic nanocages perform better than all the reported dual catalysts in acidic media, with a low ORR‐OER overpotential gap of only 704 mV at a Pt‐Ir‐Pd loading of 16.8 µgPt+Ir+Pd cm?2geo. For ORR at 0.9 V, when benchmarked against the commercial Pt/C and Pt‐Pd nanocages, the trimetallic nanocages exhibit an enhanced mass activity of 0.52 A mg?1Pt+Ir+Pd (about four and two times as high as those of the Pt/C and Pt‐Pd nanocages) and much improved durability. For OER, the trimetallic nanocages show a remarkable mass activity of 0.20 A mg?1Pt+Ir at 1.53 V, which is 16.7 and 4.3 fold relative to those of the Pt/C and Pt‐Pd nanocages, respectively. These improvements can be ascribed to the highly open structure of the nanocages, and the possible electronic coupling between Ir and Pt atoms in the lattice. 相似文献
13.
《Liver Transplantation》2018,8(1)
Nonprecious metal catalysts (NPMCs) Fe? N? C are promising alternatives to noble metal Pt as the oxygen reduction reaction (ORR) catalysts for proton‐exchange‐membrane fuel cells. Herein, a new modulation strategy is reported to the active moiety Fe? N4 via a precise “single‐atom to single‐atom” grafting of a Pt atom onto the Fe center through a bridging oxygen molecule, creating a new active moiety of Pt1? O2? Fe1? N4. The modulated Fe? N? C exhibits remarkably improved ORR stabilities in acidic media. Moreover, it shows unexpectedly high catalytic activities toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with overpotentials of 310 mV for OER in alkaline solution and 60 mV for HER in acidic media at a current density of 10 mA cm?2, outperforming the benchmark RuO2 and comparable with Pt/C(20%), respectively. The enhanced multifunctional electrocatalytic properties are associated with the newly constructed active moiety Pt1? O2? Fe1? N4, which protects Fe sites from harmful species. Density functional theory calculations reveal the synergy in the new active moiety, which promotes the proton adsorption and reduction kinetics. In addition, the grafted Pt1? O2? dangling bonds may boost the OER activity. This study paves a new way to improve and extend NPMCs electrocatalytic properties through a precisely single‐atom to single‐atom grafting strategy. 相似文献
14.
Single‐Atom to Single‐Atom Grafting of Pt1 onto FeN4 Center: Pt1@FeNC Multifunctional Electrocatalyst with Significantly Enhanced Properties
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiaojun Zeng Jianglan Shui Xiaofang Liu Qingtao Liu Yongcheng Li Jiaxiang Shang Lirong Zheng Ronghai Yu 《Liver Transplantation》2018,8(1)
Nonprecious metal catalysts (NPMCs) Fe?N?C are promising alternatives to noble metal Pt as the oxygen reduction reaction (ORR) catalysts for proton‐exchange‐membrane fuel cells. Herein, a new modulation strategy is reported to the active moiety Fe?N4 via a precise “single‐atom to single‐atom” grafting of a Pt atom onto the Fe center through a bridging oxygen molecule, creating a new active moiety of Pt1?O2?Fe1?N4. The modulated Fe?N?C exhibits remarkably improved ORR stabilities in acidic media. Moreover, it shows unexpectedly high catalytic activities toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with overpotentials of 310 mV for OER in alkaline solution and 60 mV for HER in acidic media at a current density of 10 mA cm?2, outperforming the benchmark RuO2 and comparable with Pt/C(20%), respectively. The enhanced multifunctional electrocatalytic properties are associated with the newly constructed active moiety Pt1?O2?Fe1?N4, which protects Fe sites from harmful species. Density functional theory calculations reveal the synergy in the new active moiety, which promotes the proton adsorption and reduction kinetics. In addition, the grafted Pt1?O2? dangling bonds may boost the OER activity. This study paves a new way to improve and extend NPMCs electrocatalytic properties through a precisely single‐atom to single‐atom grafting strategy. 相似文献
15.
A Monodisperse Rh2P‐Based Electrocatalyst for Highly Efficient and pH‐Universal Hydrogen Evolution Reaction
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fulin Yang Yuanmeng Zhao Yeshuang Du Yongting Chen Gongzhen Cheng Shengli Chen Wei Luo 《Liver Transplantation》2018,8(18)
The search for Pt‐free electrocatalysts exceeding pH‐universal hydrogen evolution reaction (HER) activities when compared to the state‐of‐the‐art commercial Pt/C is highly desirable for the development of renewable energy conversion systems but still remains a huge challenge. Here a colloidal synthesis of monodisperse Rh2P nanoparticles with an average size of 2.8 nm and their superior catalytic activities for pH‐universal HER are reported. Significantly, the Rh2P catalyst displays remarkable HER performance with overpotentials of 14, 30, and 38 mV to achieve 10 mA cm?2 in 0.5 m H2SO4, 1.0 m KOH, and 1.0 m phosphate‐buffered saline, respectively, exceeding almost all the documented electrocatalysts, including the commercial 20 wt% Pt/C. Density functional theory calculations reveal that the introduction of P into Rh can weaken the H adsorption strength of Rh2P to nearly zero, beneficial for boosting HER performance. 相似文献
16.
Sharath Kandambeth Vinayak. S. Kale Dong Fan Jeremy A. Bau Prashant M. Bhatt Sheng Zhou Aleksander Shkurenko Magnus Rueping Guillaume Maurin Osama Shekhah Mohamed Eddaoudi 《Liver Transplantation》2023,13(1):2202964
Here, this work reports an innovative strategy for the synthesis of chemically robust metal–organic frameworks (MOFs), and applies them as catalysts for the electrocatalytic oxygen evolution reaction (OER). A bimetallic squarate-based MOF (Sq-MOF) with a zbr topology serves as an excellent platform for electrocatalytic OER owing to its open porous structure, high affinity toward water, and presence of catalytically active 1D metal hydroxide strips. By regulating the Ni2+ content in a bimetallic squarate MOF system, the electrochemical structural stability toward OER can be improved. The screening of various metal ratios demonstrates that Ni3Fe1 and Ni2Fe1 Sq- zbr -MOFs show the best performance for electrocatalytic OER in terms of catalytic activity and structural stability. Ni2Fe1 Sq- zbr -MOF shows a low overpotential of 230 mV (at 10 mA cm−2) and a small Tafel slope of 37.7 mV dec−1, with an excellent long-term electrochemical stability for the OER. Remarkably, these overpotential values of Ni2Fe1 Sq- zbr -MOF are comparable with those of the best-performing layered double hydroxide (LDH) systems and outperforms the commercially available noble-metal-based RuO2 catalyst for OER under identical operational conditions. 相似文献
17.
Vasanth Rajendiran Jothi Karuppasamy Karuppasamy Thandavarayan Maiyalagan Hashikaa Rajan Chi‐Young Jung Sung Chul Yi 《Liver Transplantation》2020,10(24)
Alongside rare‐earth metals, Ni, Fe, Co, Cu are some of the critical materials that will be in huge demand thanks to growth in clean‐energy sector. Herein scrap stainless steel wires (SSW) from worn‐out tires are employed as a support material for catalyst integration in the hydrogen evolution reaction (HER). In addition, SSW by corrosion engineering is exercised as an in situ formed freestanding robust electrode for the oxygen evolution reaction (OER). By superficial corrosion of SSW, inherent active species are unmasked in the form of Ni/FeOOH nanocrystallites displaying efficient water oxidation by reaching 500 mA cm?2 at low overpotential (η500) of 287 mV in 1 m KOH. Similarly, cathode scrap SSW with active (alloy) coatings of MoNi4 catalyzes the HER at η‐200 = 77 mV, with a low activation energy (Ea = 16.338 kJ mol?1) and high durability of 150 h. Promisingly, when used in industrial conditions, 5 m KOH, 343 K, these electrodes demonstrate abnormal activity by yielding high anodic and cathodic current density of 1000 mA cm?2 at η = 233 mV and η = 161 mV, respectively. This work may inspire researchers to explore and reutilize high‐demand metals from scrap for addressing critical material shortfalls in clean‐energy technologies. 相似文献
18.
Sandwich‐Like Reduced Graphene Oxide/Carbon Black/Amorphous Cobalt Borate Nanocomposites as Bifunctional Cathode Electrocatalyst in Rechargeable Zinc‐Air Batteries
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jiqing Sun Dongjiang Yang Sean Lowe Lijuan Zhang Yazhou Wang Shenlong Zhao Porun Liu Yun Wang Zhiyong Tang Huijun Zhao Xiangdong Yao 《Liver Transplantation》2018,8(27)
The inhibitively high cost of the noble‐metal‐containing materials has become a major obstacle for the large‐scale application of rechargeable zinc‐air batteries (ZABs). To solve this problem in a practical way, a green and scalable method to prepare sandwich‐like reduced graphene oxide /carbon black/amorphous cobalt borate nanocomposites (rGO/CB/Co‐Bi) is reported. These composites are shown to be a highly efficient and robust bifunctional electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this system, the spontaneous assembly of the GO sheet and CB nanoparticles is demonstrated by noncovalent interactions to build the sandwich‐like structure with hierarchical pore distribution. The impressive ORR and OER activities of the obtained nanocomposite are attributed to the high conductivity, large surface area, and the hierarchically porous channels. With room‐temperature synthesis and significant activities shown in the demonstrative battery test, the prepared nanocomposite can potentially serve as an alternative for noble‐metal‐based rechargeable ZAB cathode materials. 相似文献
19.
Bifunctional Oxygen Electrocatalysis through Chemical Bonding of Transition Metal Chalcogenides on Conductive Carbons
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Improving the electrochemical performance of both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been of great interest in emerging renewable energy technologies. This study reports an advanced bifunctional hybrid electrocatalyst for both ORR and OER, which is composed of tungsten disulphide (WS2) and carbon nanotube (CNT) connected via tungsten carbide (WC) bonding. WS2 sheets on the surface of CNTs provide catalytic active sites for electrocatalytic activity while the CNTs act as conduction channels and provide a large surface area. Moreover, the newly formed WC crystalline structure provides an easy path for electron transfer by spin coupling and helps to solve stability issues to enable excellent electrocatalytic activity. In addition, it is found that four to five layers of WS2 sheets on the surface of CNTs produce excellent catalytic activity toward both ORR and OER, which is comparable to noble metals (Pt, RuO2, etc.). These findings show the many advantages enabled by designing highly active, durable, and cost‐effective ORR and OER electrocatalysts. 相似文献
20.
Amorphous Cobalt Boride (Co2B) as a Highly Efficient Nonprecious Catalyst for Electrochemical Water Splitting: Oxygen and Hydrogen Evolution
下载免费PDF全文
![点击此处可从《Liver Transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Justus Masa Philipp Weide Daniel Peeters Ilya Sinev Wei Xia Zhenyu Sun Christoph Somsen Martin Muhler Wolfgang Schuhmann 《Liver Transplantation》2016,6(6)
It is demonstrated that amorphous cobalt boride (Co2B) prepared by the chemical reduction of CoCl2 using NaBH4 is an exceptionally efficient electrocatalyst for the oxygen evolution reaction (OER) in alkaline electrolytes and is simultaneously active for catalyzing the hydrogen evolution reaction (HER). The catalyst achieves a current density of 10 mA cm?2 at 1.61 V on an inert support and at 1.59 V when impregnated with nitrogen‐doped graphene. Stable performance is maintained at 10 mA cm?2 for at least 60 h. The optimized catalyst, Co2B annealed at 500 °C (Co2B‐500) evolves oxygen more efficiently than RuO2 and IrO2, and its performance matches the best cobalt‐based catalysts reported to date. Co2B is irreversibly oxidized at OER conditions to form a CoOOH surface layer. The active form of the catalyst is therefore represented as CoOOH/Co2B. EXAFS observations indicate that boron induces lattice strain in the crystal structure of the metal, which potentially diminishes the thermodynamic and kinetic barrier of the hydroxylation reaction, formation of the OOH* intermediate, a key limiting step in the OER. 相似文献