Frontiers in Energy Research
·
2020
·
IF 2.746
Zhou Weijun,Wang Anran,Huang Aixiang,Chen Minfeng,Tian Qinghua,Chen Jizhang,Xu Xinwu
With the advantages of intrinsic safety, low price, high output potential, and acceptable energy density, aqueous rechargeable Zn–MnO2 batteries are gradually emerging as promising energy storage devices in recent years. Unfortunately, the structural instability and poor electrical conductivity of manganese dioxides still hinder their further applications. To tackle these issues, we demonstrate a high-performance cathode material for Zn–MnO2 batteries by hybridizing lignin-derived porous carbon with δ-MnO2 (denoted as LPC/δ-MnO2). Benefiting from the high electrical conductivity of porous carbon, the LPC/δ-MnO2 cathode material can offer high discharge capacity of 332.3 mAh g–1 at 0.2 A g–1 and excellent high-rate capability (196.1 mAh g–1 at 5 A g–1). Meanwhile, the assembled Zn–MnO2 battery displays good long-term cycling stability (82% capacity retention after 1000 cycles). Such superior performances are attributed to the synergetic effect of nanostructured δ-MnO2 and porous carbon scaffold, which is in favor of rapid Zn2+ ion diffusion and large contribution ratio of pseudocapacitive Zn2+ ion intercalation. The results of this study show great prospects of hybridizing biomass-derived carbon framework with electrochemically active materials toward advanced energy storage materials.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 9
·1-9
·
IF 6.232
Wang Meng,Wang Jingjing,Wang Kangkang,Chen Tingxiang,Wang Jide
A novel magnetic porous carbon with a high specific surface and magnetization saturation, derived from a Zn/Co-MOF-5, was fabricated by direct carbonization of Zn/Co-MOF-5 without the need of additional carbon precursors under optimum pyrolysis temperature. The material was employed as an adsorbent for magnetic solid-phase extraction of four carbamates from water and tomato samples prior to high-performance liquid chromatography–tandem quadrupole mass spectrometry analysis. Under optimum conditions, the method displayed good linearity ( r > 0.9987) within the concentration range 0.05–20 ng mL −1 for water samples and 0.1–40 ng g −1 for tomato samples. The limits of detection (S/ N = 3) for the four carbamate pesticides were in the range 0.0006–0.013 ng mL −1 for water samples and 0.001–0.01 ng g −1 for tomato samples and satisfactory spiked recoveries in the range 86.1 to 109.1% were obtained with the relative standard deviation values from 2.1 to 14.0%.
Graphical abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Hairus Abdullah,Noto Susanto Gultom,Hardy Shuwanto,Worku Lakew Kebede,Dong-Hau Kuo
Zn(O,S) has been successfully doped with different amounts of Ho and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and transient photocurrent (TPC). The as-prepared Ho-doped Zn(O,S) catalysts with different Ho amounts are evaluated for hydrogen evolution reaction. The catalyst with the best performance in evolving hydrogen is further utilized to hydrogenate 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). It is found that doping with Ho obviously enhanced charge transfer and photoresponse properties of the catalyst. Therefore, the modified Zn(O,S) can optimally evolve hydrogen by 18 624 μmol/g, which is 20% higher than that of pristine Zn(O,S). Subsequently, the in situ generated hydrogen ions on catalyst surfaces also play an important role as a hydrogen source to hydrogenate 4-NP to 4-AP without any reducing agents such as NaBH4, which is commonly used as a hydrogen source. As Ho is doped in the lattices of Zn(O,S), it acts not only to separate photocarriers and to enhance the charge transfer but also to shorten the diffusion time of nitrophenolate ions to catalyst surfaces for further photocatalytic hydrogenation reaction (PHR) process. A plausible PHR mechanism has been provided to elucidate the great performance of Ho-modified Zn(O,S) for photocatalytic hydrogenation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Lili Deng,Wenzhong Sun,Zijie Shi,Wei Qian,Qian Su,Li Dong,Hongyan He,Zengxi Li,Weiguo Cheng
The development of stable and efficient catalysts is an attractive topic for green chemistry reactions under mild reaction conditions. In order to improve solvent-free synthesis of cyclic carbonates from urea and diols , a binary catalyst systems of Zn-based and different ionic liquids (ILs) were developed and examined in this study. The yield of ethylene carbonate (EC) could reach to 92.2% in the presence of C 16 mimCl/ZnCl 2 catalyst. Through exploring the structure-activity relationships of cation and anion, it was confirmed that a synergistic effect of cation and anion of catalyst had important influences on urea alcoholysis . Additionally, the controlling step of EC synthesis reaction involving the elimination of an ammonia molecule from intermediates had been revealed by in situ FT-IR. This could afford a guided insight for synthesizing cyclic carbonates with high yield. Furthermore, a possible mechanism for the catalytic process was proposed based on DFT and the experimental results via FT-IR, 1 H-NMR and 13 C NMR analysis, which revealed that not only a probable synergistic effects of cation-anion matters, but also C(2)-H of ILs and Zn 2+ played a key role in accelerating the reaction of urea alcoholysis . This catalytic mechanism study is to provide a preliminary basis to develop novel catalysts for cyclic carbonates from urea and diols through a green synthetic pathway.
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2020
·Vol. 15
·期 10
·1544-1548
·
IF 4.056
You Zhang,Jie Liu,Zhengsong Fang,Xiaofeng Lin,Wenchao Zhang,Dingshan Yu
Graphical An efficient self-standing metal-free polyaniline @carbon nanotubes (PANI@CNTs) membrane catalyst is designed and synthesized via a facile solution casting approach. Without introducing any heteroatoms into carbon lattices, the newly-produced composite catalyst exhibits remarkably improved oxygen evolution activity relative to pure CNTs. Notably, it can be directly used as an additive-free bifunctional oxygen electrode to endow a Zn-air battery with good charge/discharge performance. A facile design and fabrication of self-standing metal-free polyaniline (PANI)@carbon nanotubes (CNTs) composite membrane was initially proposed by straightforward noncovalent wrapping the polymer around pure CNTs. Without introduction of extra heteroatoms into CNTs, the optimized PANI@CNTs composite exhibits a much better electrocatalytic performance for oxygen evolution reaction (OER) than pure CNTs via favorable interfacial modification with PANI to largely expose the active sites of on the surface of pure CNTs. Besides, it displays good oxygen reduction reaction (ORR) performance. When directly utilized as bifunctional air electrode without extra additive agents, the composite membrane-enabled rechargeable Zn-air batteries not only deliver a high peak power density (201.9 W g −1 ) and a large energy density (850.3 Wh kg Zn −1 ), but also present robust cycling performance for 216 cycles with a high energy efficiency of 57.8%.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Minggui Peng,Peng Liu,Zhangjian Li,Zhe Li,Jiaming Wen,Chaobo Yan,Qi Zhang,Xierong Zeng,Jizhao Zou
Reasonable design of nanostructures is the key to efficient electro-catalytic reactions. Herein, a facile and efficient approach is used to successfully construct Co/N-doped carbon composites (Co@NCs-T). The resultant Co@NCs-900 exhibits a rose-like hierarchical porous structure with high specific surface area (SSA), which can greatly expose a large number of active sites. The embedded cobalt nanoparticles contribute to the improvement of oxygen adsorption capacity and the enhancement for corrosion resistance performance of the metal active centers. The Co-N x active sites resulted from the combination of Co and N species can increase the ORR catalytic activity. The Co@NCs-900 performs a four-electron reaction process and exhibits a good catalytic activity with a half-wave potential of 0.83 V and limiting current density of 5.93 mA cm −2 in alkaline medium. The excellent ORR electro-catalytic activities of Co@NCs-900 benefits from the synergetic effect between pyridinic-N, graphitic-N and Co-N x . The Zn-air battery assembled by Co@NCs-900 exhibits open circuit voltages of 1.441 V and a maximum power density of 57.63 mW cm −2 . Meanwhile, it shows outstanding reversibility and ultra-long-life span (1116 h, 3045 cycles). In this work, the catalyst with a rose-like structure is successfully synthesized, and the mechanism of Co-N x active sites in the ORR is investigated.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Girma Sisay,Hairus Abdullah,Dong-Hau Kuo,Worku Lakew,Hardy Shuwanto,Sleshi Fentie
The works on photocatalytic hydrogen production and green chemical conversion have received significant attention due to the current need for clean energy and a secure environment. Herein, Ce and Ga codoped Zn(O,S) has been synthesized with different amounts of Ce using facile precipitation method at a low temperature of 95 °C and characterized by XRD, SEM, HRTEM, XPS, EPR, Raman, DRS, PL, EIS, UV–vis, GC–MS, and photocurrent response measurements. The as-prepared photocatalysts were utilized for hydrogen production and hydrogenation of toxic organic compounds, viz. nitrobenzene (NB) and azobenzene (AB) into a valuable product of aniline. The incorporation of Ce and Ga into Zn(O,S) enhanced the hydrogen evolution and hydrogenation reactions of NB and AB. This notable enhancement was ascribed to the synergistic effects of Ce and Ga dopants to form positively charged defects that trap the photogenerated electron. The trapping mechanism improves the photogenerated charge separation and transfer as confirmed with impedance spectroscopy (EIS), transient photocurrent response, and PL measurements. The highest hydrogen production was attained by 15Ce-5Ga-Zn(O,S) with a rate of 7130 μmol∙g − 1 ∙h − 1 in 10% ethanol solution. In addition, NB and AB were effectively converted to aniline in 15 min and 30 min, respectively. A plausible photocatalytic hydrogenation mechanism for both hydrogenation of NB and AB is proposed with the steps of surface adsorption, molecular diffusion, pinning at oxygen vacancy sites, and hydrogenation reaction with the help of in situ generated H + coupled with electrons.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
You Zhang,Juping Wang,Shuai Zhao,Maria Serdechnova,Carsten Blawert,Hao Wang,Mikhail L. Zheludkevich,Fei Chen
A promising double-ligand strategy for the delivery of active corrosion inhibitors by a Zn(II)-based metal–organic framework (Zn-MOF) is developed. Zn-MOF compounds were synthesized by a facile one-pot solvothermal method and characterized. The Zn-MOF is based on the corrosion inhibitor benzotriazole (BTA) and 2,5-furandicarboxylic acid (H2FDA) ligand, which is a promising renewable building block alternative to terephthalic or isophthalic acid. The crystal structure and morphology are characterized by single-crystal X-ray diffraction analysis, powder X-ray diffraction analysis (PXRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The synthesized MOF crystallites are in the trigonal space group R3c with the cell parameters in a three-dimensional (3D) anionic framework. Their ability to inhibit the corrosion process of aluminum alloy 2A12 in NaCl solution was also evaluated by immersion tests in solutions with and without a MOF. The postcorrosion analysis was performed by SEM and X-ray photoelectron spectroscopy (XPS). Additional information about the inhibition efficiency was obtained by electrochemical impedance spectroscopy (EIS). The results suggest that the as-synthesized MOF can release the inhibitors and form protective layers effectively on the surface of the aluminum alloy. The use of inhibitor-loaded MOF nanocontainers provides promising opportunities for the smart delivery of inhibitors and effective corrosion protection of 2A12 aluminum alloys.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 39
·22453-22462
·
IF 10.733
Liang Yan,Bing Zhang,Junlu Zhu,Zhonggang Liu,Haiyan Zhang,Yunyong Li
Exploring highly efficient and cost-effective electrocatalysts has become imperative for neutral-pH water splitting, which is environmentally friendly and can reduce the cost of electrolysis systems. Here, we report an effective strategy to design a novel type of callistemon-like Zn and S codoped CoP nanorod clusters by introducing both Zn and S into cobalt phosphide, thereby creating electrocatalysts for highly efficient and stable neutral water splitting. The best Zn and S codoped CoP nanorod clusters on carbon paper (Zn,S–CoP NRCs/CP) require overpotential values of 67 and 391 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm−2 in 1.0 M phosphate-buffered solution, respectively. Remarkably, this enables a neutral electrolyzer to deliver 10 mA cm−2 at a low cell voltage of 1.70 V, which is superior to those afforded by the Pt/C/CP‖IrO2/CP couple and most of the state-of-the-art electrocatalysts. Impressively, this electrolyzer can be powered by an AA battery (∼1.5 V). Density functional theory computations and systematic experiments have verified that the improved HER and OER activities originate from the optimized electronic structures that can facilitate the adsorption and desorption of hydrogen intermediates after introducing Zn and S and accelerating the formation of oxygenated intermediates on CoOOH, respectively. This work provides a new strategy to boost the performance of transition metal phosphides for neutral water or seawater splitting.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Chen Wang,Zhongfang Li,Likai Wang,Xueliang Niu,Suwen Wang
Exploring the oxygen electrocatalysts with both high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance is crucial to developing the rechargeable Zn–air batteries (ZABs). Herein, we prepared a bifunctional three-dimensional graphene-like iron-nitrogen doped oxygen electrocatalyst (3D Fe/N-G#4, polyacrylamide (PAM):NaCl = 1:4, mass ratio) by a facile synthesis with PAM and iron as precursors and NaCl as template. The NaCl template melted during the pyrolysis process, which could fabricate a stable 3D network structure in the precursors to form more mesopores, higher specific surface area, and more exposed active sites and prevent the loss of precursors. The low-cost and water-soluble PAM as the N precursor provided abundant N and dissolved adequately with NaCl solution. The Fe precursor coordinated with the N to form Fe-Nx active sites that were investigated by HR-TEM, XRD, XPS, and RDE techniques. The 3D Fe/N-G#4 exhibited excellent electrochemical activity with a high half-wave potential (0.852 V vs RHE) for ORR and a low overpotential (393 mV at 10 mA cm–2) for OER in the alkaline conditions. In addition, the homemade rechargeable ZAB based on the prepared 3D Fe/N-G#4 exhibits high power density (168.2 mW cm–2) and excellent discharge-charge cycling stability (over 60 h) at 20 mA cm–2. This work provides a cost-efficient, simple, and eco-friendly method to synthesize excellent bifunctional non-noble electrocatalysts for commercialization of ZABs.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Jie Di,Junxia Guo,Nannan Wang,Guiping Ma
In this work, unique sugar-coated haws stick-like core–shell ZIF-67@PAN-HCCP-MIM-FeCl3 nanofibers were successfully prepared by electrospinning and an in situ nanocrystal growth process. After carbonization of the as-synthesized nanofibers at various temperatures, the resulting sample Fe/Co-N/P-9 (carbonized at 900 °C) retained the presented a sugar-coated haws stick-like structure. The internal carbon nanofiber acts like a “stick” as a support, the “haws” composed of Co2P and Fe5C2 nanoparticles act as catalytic active sites, and the graphite carbon acts as “sugar” to protect particles from detachment. The channel gap between inner core and outer layer can improve the mass transfer process. Owing to these special structure and unique composition features, Fe/Co-N/P-9 exhibited excellent oxygen reduction reaction (ORR) performance with an onset potential of 0.96 V (vs RHE) and a half wave potential of 0.85 V (vs RHE) in 0.1 M KOH solution. Fe/Co-N/P-9 also showed good catalytic stability and methanol tolerance. In addition, the rechargeable Zn–air battery fabricated by Fe/Co-N/P-9 exhibited a galvanostatic discharge voltage of 1.25 V, a higher specific capacity of 565 mAh/gZn, and a better cycle stability than Pt/C+RuO2.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Shan Yuan,Miaomiao Weng,Dajun Liu,Xingquan He,Li−Li Cui,Tewodros Asefa
Platinum (Pt)-based catalysts are widely used for the oxygen reduction reaction (ORR) in many energy conversion and storage devices, such as fuel cells and metal–air batteries. However, Pt is among the least earth abundant and most expensive elements; as a result, these energy devices are currently difficult to scale up. This has motivated researchers to try to develop sustainable and alternative catalysts that can replace Pt as well as other noble metal-based catalysts. Herein, novel Co nanocrystals-loaded, Zn, N, and S codoped carbon materials, dubbed (Co, Zn)/NSC, which have hollow spherical structures and which can serve as efficient ORR catalysts, are developed via a facile synthetic method involving microemulsion and pyrolysis. The key in the synthesis of these nonprecious metal-containing heteroatom-doped nanostructured carbon catalysts is the preparation of nanosized, mixed metal–organic frameworks (MOFs) in solution using microemulsion, and the exploitation of their morphology to produce hollow spherical structures via pyrolysis. Elemental mapping shows the presence of Co, Zn, N, and S atoms throughout the structures of the materials. The material obtained at pyrolysis temperature of 800 °C, denoted (Co, Zn)/NSC-800, exhibits excellent electrocatalytic activity for ORR in alkaline and acidic media, with onset potentials of 1.000 and 0.802 V vs RHE, respectively. In addition, the catalyst is stable and tolerates the methanol crossover reaction in both cases. Thus, this material has the potential to replace Pt catalysts in fuel cells. Moreover, the synthetic approach used to make it can be extended to produce other robust, nonprecious transition metal-based catalysts for ORR.
✓ 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）