| 1. |
- Chen, Anqi, et al.
(författare)
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Highly Sensitive Graphene Oxide-based Fabry-Perot Low-frequency Acoustic Sensor With Low-coherence Polarized Demodulation Using Three-step Phase-Shifting Arctan Algorithms
- 2024
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Developing low-frequency acoustic senor with high sensitivity is crucial for diverse applications, ranging from seismic monitoring, military operations, to pipeline surveillance. Here, we have proposed a high-sensitivity graphene oxide (GO)-based Fabry-Perot low-frequency sensor, in which a 170 nm thick, large-area and uniformly GO film was prepared by a vacuum filtration method. To enhance the accuracy and stability of the sensor, a low-coherence interference system based on birefringent crystal blocks was designed utilizing a three-step phase-shifting arctangent algorithm. Our sensor exhibited a sensitivity of -93.48 dB re 1 rad/μPa at 6-60 Hz with a fluctuation of 0.6 dB. The minimum detectable pressure of the sensor was measured at 0.37 μPa/Hz1/2 @20 Hz with a signal to noise ratio of 135.41 dB. Overall, this sensor offers simplicity in preparation, high sensitivity, low detectable sound pressure, making it a significant asset for low-frequency acoustic applications.
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| 2. |
- Hou, Lili, 1984, et al.
(författare)
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Efficient Visible‐to‐UV Photon Upconversion Systems Based on CdS Nanocrystals Modified with Triplet Energy Mediators
- 2021
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 31:47
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Tidskriftsartikel (refereegranskat)abstract
- Developing high-performance visible-to-UV photon upconversion systems based on triplet–triplet annihilation photon upconversion (TTA-UC) is highly desired, as it provides a potential approach for UV light-induced photosynthesis and photocatalysis. However, the quantum yield and spectral range of visible-to-UV TTA-UC based on nanocrystals (NCs) are still far from satisfactory. Here, three different sized CdS NCs are systematically investigated with triplet energy transfer to four mediators and four annihilators, thus substantially expanding the available materials for visible-to-UV TTA-UC. By improving the quality of CdS NCs, introducing the mediator via a direct mixing fashion, and matching the energy levels, a high TTA-UC quantum yield of 10.4% (out of a 50% maximum) is achieved in one case, which represents a record performance in TTA-UC based on NCs without doping. In another case, TTA-UC photons approaching 4 eV are observed, which is on par with the highest energies observed in optimized organic systems. Importantly, the in-depth investigation reveals that the direct mixing approach to introduce the mediator is a key factor that leads to close to unity efficiencies of triplet energy transfer, which ultimately governs the performance of NC-based TTA-UC systems. These findings provide guidelines for the design of high-performance TTA-UC systems toward solar energy harvesting.
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| 3. |
- Hou, Lili, et al.
(författare)
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Optically switchable organic light-emitting transistors
- 2019
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Ingår i: Nature Nanotechnology. - : Springer Science and Business Media LLC. - 1748-3387 .- 1748-3395. ; 14:4, s. 347-353
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Tidskriftsartikel (refereegranskat)abstract
- Organic light-emitting transistors are pivotal components for emerging opto- and nanoelectronics applications, such as logic circuitries and smart displays. Within this technology sector, the integration of multiple functionalities in a single electronic device remains the key challenge. Here we show optically switchable organic light-emitting transistors fabricated through a judicious combination of light-emitting semiconductors and photochromic molecules. Irradiation of the solution-processed films at selected wavelengths enables the efficient and reversible tuning of charge transport and electroluminescence simultaneously, with a high degree of modulation (on/off ratios up to 500) in the three primary colours. Different emitting patterns can be written and erased through a non-invasive and mask-free process, on a length scale of a few micrometres in a single device, thereby rendering this technology potentially promising for optically gated highly integrated full-colour displays and active optical memory.
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| 4. |
- Jansson, Helen, 1964, et al.
(författare)
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Carbon enhanced cementitious coatings: Alternative anode materials for impressed current cathodic protection systems intended for reinforced concrete
- 2024
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Ingår i: Materials and Corrosion - Werkstoffe und Korrosion. - 1521-4176 .- 0947-5117. ; 75:6, s. 705-718
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the functionality of self-formulated carbon-based conductive coatings (CBCCs) with incorporation of graphite as the anode in an impressed current cathodic protection system is studied. The anode materials are tested and evaluated for long-term durability and performance by an accelerated durability test method. The results show that the functional time is highly dependent on the acceleration factor, and thus the charge passed through the material during testing, as well as the material composition. From the results, there are also indications that the addition of graphene into the CBCC matrix has a positive effect on the homogeneity of the material, but without any major influence on the conductivity and performance.
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| 5. |
- Martin, N., et al.
(författare)
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Chemical Functionalization of 2D Materials
- 2020
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Ingår i: Chemistry - A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 26:29, s. 6292-6295
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This Special Issue of Chemistry-A European Journal is dedicated to the Chemical Functionalization of 2D Materials, and features some great contributions from experts in the field of 2D materials. This issue was originally assembled to support the Symposium G "Chemical Functionalization of 2D Materials" at the European Materials Research Society (E-MRS) 2020 Spring Meeting, which was originally scheduled to be held in Strasbourg, France, from May 25th to 29th, 2020. Although the E-MRS 2020 Spring Meeting has been cancelled due to the COVID-19 outbreak, the publication of this Special Issue has proceeded and has become even more important as the contributors discuss diverse and timely research themes related to 2D materials. In this Editorial, a brief overview of the different types of 2D materials is given, together with the chemical functionalization schemes that can be applied to them to achieve new properties as well as enable improved performance in applications. Some of the articles featured in this Special Issue are also highlighted, with the hope that they will inspire readers and further advance the field.
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| 6. |
- Peng, Cheng, 1993, et al.
(författare)
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Aqueous Asymmetric Supercapacitors with Pyrenetetraone-Derived Pseudocapacitive Polymer-Functionalized Graphene Cathodes Enabling a 1.9 V Operating Window
- 2024
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Ingår i: Advanced Energy and Sustainability Research. - 2699-9412. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Pseudocapacitive polymers have garnered significant attention in the realm of supercapacitors due to their versatile molecular design capabilities, cost-effectiveness, and impressive electrical conductivity. However, limited by the low capacity and short cycle life, the investigation on conducting polymers for potential electrode materials is still insufficient. Herein, a series of pyrenetetraone-derived polymers with pyrazine units are designed and synthesized. Furthermore, UV–vis spectroscopy demonstrates the different interaction behavior between the polymers and reduced graphene oxide (rGO), which can further indicate the performance difference of the composite electrodes. As a result, the pseudocapacitive polymer/rGO composite electrode (2/1 PPYT/rGO) exhibits a high specific capacitance of 591 F g−1 at 1 A g−1 in a 1 m sulfuric acid electrolyte. The asymmetric supercapacitor (ASC) assembled by the 2/1 PPYT/rGO cathode and the annealed Ti3C2Tx anode (2/1 PPYT/rGO//A-Ti3C2Tx) delivers an excellent energy density of 38.1 Wh kg−1 at a power density of 950 W kg−1. Additionally, both devices demonstrate outstanding stability, retaining over 90% of their capacity after 15 000 charge/discharge cycles. As a result, these carefully engineered organic polymers, with their well-thought-out structural designs, showcase exceptional electrochemical performance, positioning them as highly promising candidates for the next generation of high-performance energy storage materials.
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| 7. |
- Peng, Cheng, 1993, et al.
(författare)
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Chemical Functionalization of Graphene Nanoplatelets with Hydroxyl, Amino, and Carboxylic Terminal Groups
- 2021
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Ingår i: Chemistry (Switzerland). - : MDPI AG. - 2624-8549. ; 3:3, s. 873-888
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Forskningsöversikt (refereegranskat)abstract
- As the most studied two-dimensional material, graphene is still attracting a lot of attention from both academia and industry due to its fantastic properties such as lightness, excellent mechanical strength, and high conductivity of heat and electricity. As an important branch of graphene materials, graphene nanoplatelets show numerous applications such as in coating, fillers of polymer composites, energy conversion and storage devices, sensing, etc. Chemical functionalization can introduce different functional groups to graphene nanoplatelets and can potentially endow them with different properties and functions to meet the increasing demand in the fields mentioned above. In this minireview, we present an overview of the research progress of functionalized graphene nanoplatelets bearing hydroxyl, amino, and carboxylic terminal groups, including both covalent and noncovalent approaches. These terminal groups allow subsequent functionalization reactions to attach additional moieties. Relevant characterization techniques, different applications, challenges, and future directions of functionalized graphene nanoplatelets are also critically summarized.
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| 8. |
- Shi, Mangmang, et al.
(författare)
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A Novel Aqueous Asymmetric Supercapacitor based on Pyrene-4,5,9,10-Tetraone Functionalized Graphene as the Cathode and Annealed Ti3C2Tx MXene as the Anode
- 2023
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 19, s. 2301449-
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Tidskriftsartikel (refereegranskat)abstract
- Asymmetric supercapacitors (ASCs), employing two dissimilar electrode materials with a large redox peak position difference as cathode and anode, have been designed to further broaden the voltage window and improve the energy density of supercapacitors. Organic molecule based electrodes can be constructed by combining redox-active organic molecules with conductive carbon-based materials such as graphene. Herein, pyrene-4,5,9,10-tetraone (PYT), a redox-active molecule with four carbonyl groups, exhibits a four-electron transfer process and can potentially deliver a high capacity. PYT is noncovalently combined with two different kinds of graphene (Graphenea [GN] and LayerOne [LO]) at different mass ratios. The PYT-functionalized GN electrode (PYT/GN 4–5) possesses a high capacity of 711 F g−1 at 1 A g−1 in 1 M H2SO4. To match with the PYT/GN 4–5 cathode, an annealed-Ti3C2Tx (A-Ti3C2Tx) MXene anode with a pseudocapacitive character is prepared by pyrolysis of pure Ti3C2Tx. The assembled PYT/GN 4–5//A-Ti3C2Tx ASC delivers an outstanding energy density of 18.4 Wh kg−1 at a power density of 700 W kg−1. The PYT-functionalized graphene holds great potential for high-performance energy storage devices.
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| 9. |
- Shi, Mangmang, et al.
(författare)
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Aqueous Organic Batteries Using the Proton as a Charge Carrier
- 2023
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Ingår i: Advanced Materials. - 0935-9648 .- 1521-4095. ; 35:42
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Forskningsöversikt (refereegranskat)abstract
- Benefiting from the merits of low cost, nonflammability, and high operational safety, aqueous rechargeable batteries have emerged as promising candidates for large-scale energy-storage applications. Among various metal-ion/non-metallic charge carriers, the proton (H+) as a charge carrier possesses numerous unique properties such as fast proton diffusion dynamics, a low molar mass, and a small hydrated ion radius, which endow aqueous proton batteries (APBs) with a salient rate capability, a long-term life span, and an excellent low-temperature electrochemical performance. In addition, redox-active organic molecules, with the advantages of structural diversity, rich proton-storage sites, and abundant resources, are considered attractive electrode materials for APBs. However, the charge-storage and transport mechanisms of organic electrodes in APBs are still in their infancy. Therefore, finding suitable electrode materials and uncovering the H+-storage mechanisms are significant for the application of organic materials in APBs. Herein, the latest research progress on organic materials, such as small molecules and polymers for APBs, is reviewed. Furthermore, a comprehensive summary and evaluation of APBs employing organic electrodes as anode and/or cathode is provided, especially regarding their low-temperature and high-power performances, along with systematic discussions for guiding the rational design and the construction of APBs based on organic electrodes.
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| 10. |
- Smith, Anderson David, 1985, et al.
(författare)
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Carbon-Based Electrode Materials for Microsupercapacitors in Self-Powering Sensor Networks : Present and Future Development
- 2019
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 19:19
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need to fulfill future energy demands for micro and nanoelectronics. This work outlines a number of important design features for carbon-based microsupercapacitors, which enhance both their performance and integration potential and are critical for complimentary metal oxide semiconductor (CMOS) compatibility. Based on these design features, we present CMOS-compatible, graphene-based microsupercapacitors that can be integrated at the back end of the line of the integrated circuit fabrication. Electrode materials and their interfaces play a crucial role for the device characteristics. As such, different carbon-based materials are discussed and the importance of careful design of current collector/electrode interfaces is emphasized. Electrode adhesion is an important factor to improve device performance and uniformity. Additionally, doping of the electrodes can greatly improve the energy density of the devices. As microsupercapacitors are engineered for targeted applications, device scaling is critically important, and we present the first steps toward general scaling trends. Last, we outline a potential future integration scheme for a complete microsystem on a chip, containing sensors, logic, power generation, power management, and power storage. Such a system would be self-powering.
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