INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Feifei Fang,Lu Liu,Luofu Min,Li Xu,Wen Zhang,Yuxin Wang
To increase the conductivity of proton exchange membranes in the membrane thickness direction, a novel mixed matrix membrane of Nafion ionomer and sulfonated graphene nanoplates (sGNP) with aligned proton channels is prepared with the assistance of an electric field. A high voltage alternative electric field is applied to a casting solution consisting of Nafion ionomer , sGNP, N, N-dimethylformamide (DMF), and p-xylene (PX) while evaporating the solvents. The sGNP, naturally attracting the ionic groups of Nafion ionomer to their vicinity, is polarized and rotated under the electric field, leaving aligned proton channels in the solidified membrane. The trans-plane proton conductivity of the mixed matrix membrane can reach 0.155 S cm −1 at 80 °C and 100% RH, an increase of 48% as compared with the conventional cast Nafion membrane . Accordingly, the peak power output of H 2 /O 2 fuel cell with the mixed matrix membrane increases by 15%, reaching 440 mW cm −2 at 80 °C.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Zinan Zhi,Wanshuo Gao,Jiawei Yang,Chong Geng,Boxuan Yang,Chen Tian,Shurui Fan,Haoyi Li,Jinpo Li,Zhongqiu Hua
In the present work, an amperometric electrochemical hydrogen (H 2 ) sensor was fabricated by solid polymer electrolyte and screen-printed electrodes (SPE). The carbon electrode modified by Pt/C/Nafion film gave an enhanced sensitivity. The Pt/C/Nafion suspension could be directly added dropwise to the carbon electrodes for modification, which was simple and efficient. For hydrogen sensors, it was proved that hydrogen and Pt nanoparticles in aprotic electrolyte were the electrochemical behavior of single electron transfer in an anaerobic environment and the coupling electrochemical behavior with oxygen in an aerobic environment. A solid amperometric gas sensor was fabricated by a 3D printing package with a solid polymer electrolyte and porous ceramic subtracts printed with modified electrodes. It was indicated that the sensor device fabrication was quite simple; however, the sensitivity could be greatly improved.
研究领域:
材料科学
·
电化学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Polymer Science
·
2024
·
IF 3.4
Shuangjie Liu,Jialin Yu,Yongping Hao,Feng Gao,Mo Zhou,Lijun Zhao
Using Nafion212 membrane and TEOS solution as raw materials, Nafion212/SiO2 composite membranes were prepared. In the in situ sol-gel reaction process, a series of Nafion/SiO2 composite membranes were prepared by varying the reaction temperature and reaction time. The effects of different modification schemes on Nafion/SiO2 composite membranes were studied using SEM, EDS, TEM, TGA, XRD, and mechanical tensile experiments, among other methods. The results show that Nafion/SiO2 composite membranes prepared at 3°C exhibit a well-separated phase structure and excellent water retention properties, with a water uptake of 29.23% and a swelling ratio of 24.25%. These membranes also demonstrate outstanding physical and chemical performance, with a maximum tensile stress of 13.6 MPa and an elongation at a break of 270%. At 110°C, the proton conductivity of the Nafion/SiO2 composite membrane reaches 0.172 S/cm, meeting the requirements for high-temperature proton exchange membrane fuel cells.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Hui Liu,Zhujiang Wang,Hao Chen,Yushan Tu,Jun Wu,Fenghua Shen,Xudong Liu,Yingxue Fu,Lin Wu,Jiaqi Long,Kaisong Xiang
The electrocatalytic reduction of SO2 to produce H2S is a critical approach for achieving the efficient utilization of sulfur resources. At the core of this approach for commercial applications lies the imperative need to elevate current density. However, the challenges posed by high current density manifest in the rapid depletion of protons, leading to a decrease in SO2 partial pressure, consequently hampering the generation and separation of H2S. Here, we demonstrate an effective solution to alleviate the problem of insufficient supply of protons by employing Nafion polymer as the proton conductor to modified Cu catalysts surface, creating a proton-enriched layer to boost H2S generation. It was observed that Nafion shortens the hydrogen bonds with water molecules in the electrolyte via its sulfonic acid groups, benefiting the proton transfer and consequently increasing the proton density on the electrode surface by 5-fold. With the Nafion-modified catalyst, the H2S partial current density and separation efficiency reached 205.9 mA·cm–2 (1.01 mmol·cm–2·h–1) and 87.8%, which were 1.34 and 1.22 times that on unmodified Cu, respectively. This work highlights the practicality of fabricating a proton conductor via ionic polymer for the control over product selectivity in pH-sensitive reactions under high current density.
研究领域:
电化学
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材料科学
·
催化
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2015
·
IF 3.313
Lei Wang,Pengjin Ye,Fang Yuan,Shuzhen Li,Zixin Ye
In this work, we report a novel means, named liquid phase in-situ hydrodeoxygenation of bio-derived phenol to cyclohexene and cyclohexane over Raney Ni and Nafion/SiO 2 . In this method, producing hydrogen , hydrogenation and dehydration are merged and coupled owing to the close reaction conditions. The overall specific reaction pathway was studied and influences of Nafion loading, temperature, H 2 O/MeOH ratio and the quantity of catalysts on the reaction were also researched. In terms of 3 g phenol, the suitable operating conditions are drawn as follows: the Nafion loading 13 wt%, the reaction temperature 200 °C, H 2 O/MeOH ratio 20 mL:15 mL, Raney Ni 1 g, Nafion/SiO 2 0.3 g. The conversion rate of phenol and the total yield of cyclohexene and cyclohexane can reach respectively 100% and 87%. The whole reaction system is performed in the liquid phase using in situ hydrogen produced from methanol aqueous-phase reforming, not requiring an external source of hydrogen. The operating conditions are gentle, and the cost is considerably reduced.
研究领域:
化学工程
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 4
·3195-3203
·
IF 8.897
Wang Yan,Gao Hexiang,Wu Wenjia,Zhou Zhuofan,Yang Zhiwei,Wang Jingtao,Zou Yecheng
Porous laminar membranes hold great promise to realize ultrafast ion transfer if efficient and stable transfer channels are constructed in vertical direction. Here, metal-organic framework (MOF) nanosheets bearing imidazole molecules in the pores were designed as building blocks to assemble free-standing MOF laminar membrane. Then, Nafion chains were threaded into the pores induced by electrostatic attraction from imidazole molecules by slowly filtering dilute Nafion solution. We demonstrate that the threaded Nafion chains lock adjacent MOF nanosheets, affording highly enhanced structural stability to the resultant laminar membrane with almost no water swelling. Significantly, abundant acid-base pairs are formed in the pores along Nafion chains, working as efficient, continuous conduction pathways in vertical direction. Proton conductivities as high as 110 and 46 mS·cm −1 are obtained by this membrane under 100% and 40% relative humidity (RH), respectively, which are two orders of magnitude higher than that of pristine MOF membrane. The conductivity under low humidity (40% RH) is even over 2 times higher than that of commercial Nafion membrane, generating the maximum power density of 1,100 mW·cm −2 in hydrogen fuel cell (vs. 291 mW·cm −2 of Nafion membrane). Besides, the influence of water state on proton transfer in confined space is investigated in detail.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Shilong Liu,Gangqiang Tang,Yifan Pan,Shunan An,Yujun Ji,Yanjie Wang
As a type of smart material, flexible stimulus-responsive actuators have become a hot research topic nowadays. However, flexible actuators responding to a single stimulus source are susceptible to external perturbations, which may lead to an unstable function or even failure. Therefore, in this paper, we proposed a bilayer actuator that can be driven by both humidity and light by combining the humidity-sensitive Nafion, carboxylated multiwalled carbon nanotubes (cMWCNT) with excellent photothermal conversion properties, and commercial polyethylene (PE) tape with good humidity insensitivity and thermal expansion. First, the cMWCNT-Nafion film was prepared by a solution casting method and bonded together with PE tape to obtain a bilayer actuator. Then, the effects of the cMWCNT mass fraction and film thickness on the humidity and light response performance of the bilayer actuator were investigated. The optimal ratios of raw materials were obtained for different stimulation sources, respectively. Furthermore, the performance of the bilayer actuator with the optimal ratios was tested; it was verified that the proposed dual-responsive actuator can realize different degrees of bending deformation under different relative humidity (RH) and ultraviolet (UV) light intensity with good stability. Finally, the application potential in multiple scenarios was further verified by applying the prepared cMWCNT-Nafion/PE bilayer actuator to a smart window, crawling robot, and flexible gripper. This paper will provide a meaningful reference for the development and performance optimization of high-performance dual-responsive actuators.
研究领域:
材料科学
·
智能材料
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Lingchu Huang,Weijia Li,Huaiyuan Sun,Jianyu Zhang,Bin Wang,Qi Lu,Tong Wang,Xishuang Liang,Fangmeng Liu,Peng Sun,Fengmin Liu,Geyu Lu
Expanding the application field of fuel cell type gas sensors is of great significance for achieving high sensitivity, real-time gas detection at room temperature. Here, we developed a fuel cell type NO 2 gas sensor based on MoS 2 nanosheet/Carbon fiber (CF) sensing electrode and Nafion proton conductor , enabling the fuel cell type sensor to detect NO 2 for the first time. The effect of MoS 2 loadings(10, 20, 40, 60 and 80 mg) on the sensors’ performance and the sensitizing mechanism are investigated, the sensor containing 40 mg MoS 2 exhibits the best performance, which can be attributed to the large number of active sites and efficient carrier transport properties of the corresponding electrode materials. At room temperature, the optimal sensor demonstrates a sensitivity of 45.6 nA/ppm to 1–50 ppm NO 2 and an ultra-low detection limit of 28.8 ppb, both the response and recovery time are less than 60 s. This work not only develops a highly sensitive, reversible and fast response NO 2 gas sensor, but also provides insights into sensing electrochemistry, material selection and catalyst/support materials, offering guidelines for future fuel cell type gas sensors to monitor a wider range of environmental pollutants.
研究领域:
材料科学
·
环境科学
·
电化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Minglu Zhang,Man Wang,Xiaojun Zhang,Chengwei Zhang,Manhong Li,Sujun Yu
Ionic polymer-metal composites (IPMCs) composed of Nafion film and platinum deposited on both faces have gained much attention in biomedical engineering as actuators because it can show large bending motion under an electric field. This study focuses on the design of a multilayered IPMC actuator based on sulfonated graphene oxide (SGO) modified macroporous Nafion film. The Nafion film is firstly fabricated via templating technique by using silica spheres as template and SGO as a conductive agent dispersed in Nafion film. Then, Pt nanoparticles are deposited on both faces of the as-prepared Nafion film to fabricate the actuator (denoted as IPMC-SGO-M). In the IPMC-SGO-M, macropores and SGO co-exist in the Nafion film, which can effectively enhance the rapid transport of ions and electrons. In addition, small Pt nanoparticles are uniformly dispersed on the surface of the Nafion film, which can improve the water-uptake capability and charge redistribution between two layers of electrode regions. As a result, the tip displacements of the IPMC-SGO-M are 1.7-fold and 1.9-fold higher than that of the IPMC based on macroporous Nafion film (IPMC-M) under 6.2 and 6.6 V, respectively. The blocking forces of the IPMC-SGO-M are about 2.6-fold and 2.3-fold higher than that of IPMC-M under 6.2 and 6.6 V, respectively.
研究领域:
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Hang Wang,Xiaojie Li,Xupin Zhuang,Bowen Cheng,Wei Wang,Weimin Kang,Lei Shi,Hongjun Li
Proton currents are an integral part of the most important energy-converting structures in biology. We prepared a new type of bioinspired Nafion (Bio-Nafion) membrane composited of biofunctional SiO 2 (Bio-SiO 2 ) nanofiber and Nafion matrix . SiO 2 nanofibers were prepared by electrospinning silica sol prepared from tetraethyl orthosilicate . Meanwhile, Bio-SiO 2 nanofibers were synthesized by immobilizing amino acids (cysteine, serine , lysine, and glycine) on SiO 2 nanofibers, which acted as efficient proton-conducting pathways that involved numerous H + transport sites. In our study, the SiO 2 nanofibers biofunctionalized with cysteine were further oxidized, and the composite membranes were designated as Nafion-Cys, Nafion-Lys, Nafion-Ser, and Nafion-Gly, respectively. We then investigated the different polar groups ( SO 3 H, OH, and NH 2 ) of the amino acids that contributed to membrane properties of thermal stability, water uptake (WU), dimensional stability, proton conductivity , and methanol permeability . Nafion-Cys exhibited the highest proton conductivity of 0.2424 S/cm (80 °C). Nafion-Gly showed the lowest proton conductivity and WU because glycine contains the least number of hydrophilic groups among the amino acids. Overall, the introduction of Bio-SiO 2 nanofiber to composite membranes significantly improved proton conductivity, dimensional stability, and methanol permeability.
研究领域:
材料科学
·
能源科学
·
生物仿生学
✓ 已验证
产品关联
DOI
高影响因子
ECS Journal of Solid State Science and Technology
·
2021
·Vol. 10
·期 2
·025003
·
IF 2.07
Peng-Lin Mou,Wan-Qing Huang,Feng-Jie Yan,Xi Wan,Feng Shao
Nafion is the most classic and also the mostly used proton exchange membrane material for polymer electrolyte fuel cells. It has excellent proton transport property and chemical-physical stability. Yet to the best knowledge of the authors, Nafion as the gate dielectric had not been reported for the low voltage electric-double-layer transistors that gated by ion-based dielectrics. It is the aim of this work to explore the behavior of Nafion as the gate dielectric in metal-oxide electric-double-layer transistors. The effects of pretreatment with H2O2 and H2SO4 on the film properties were characterized and the correlations with EDLT's static and transient characteristics were analyzed. The pretreatment process is proved to be effective in enhancing the performance of as prepared transistors. The H2O2 + 3.5 M H2SO4 treated devices showed gate voltage below 1.5 V, field-effect mobility up to 16.9 cm2 V−1s−1, on/off radio at the level of 104, small hysteresis and transient response time of within 10 ms. These results solidify our understanding in proton gated electric-double-layer transistors which is helpful in guiding the future developments.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Xiaohui Leng,Dan Luo,Zongxiang Xu,Fei Wang
Graphene oxide (GO) and its derivatives have been applied to the humidity sensing area in recent years due to its abundant hydrophilic functional groups, and proved to be ultrasensitive to the humidity changing. But the stability of the sensors is always an obstacle to their application. Besides, the long-term linearity is seldom studied. In this work, diamine modified GO (MGO) has been synthesized and mixed with Nafion polymer to form a hybrid film, and applied to the humidity sensors. We have applied two measurement methods by either fitting of the impedance spectra to extract charge transfer resistance (R ct ) or measurement of the impedance under a certain frequency, to evaluate the response to the relative humidity (RH). Both MGO and its composite show good sensitivity to the RH under the two testing methods The R ct shows good linearity at the full testing RH range even after two months, while the impedance under a certain frequency can’t keep the linear response to the RH after certain period of time. The addition of Nafion decreases the R ct and increases the sensitivity of MGO based sensor. Linearity of the sensor is improved by the combination of MGO and Nafion. Long-term testing results show the linearity of the composite sensors changes over time but always keeps a better linearity than the pure MGO sensor.
研究领域:
材料科学
·
传感技术
✓ 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）