Co-reporter:Fanhong Chen, Pengbo Wan, Haijun Xu, and Xiaoming Sun
ACS Applied Materials & Interfaces May 31, 2017 Volume 9(Issue 21) pp:17865-17865
Publication Date(Web):May 11, 2017
DOI:10.1021/acsami.7b02460
Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.Keywords: all-solid state supercapacitors; flexible electronic devices; graphene; nanocomposites; transparent conducting films;
Co-reporter:Yan-Jun Liu, Wen-Tao Cao, Ming-Guo Ma, and Pengbo Wan
ACS Applied Materials & Interfaces August 2, 2017 Volume 9(Issue 30) pp:25559-25559
Publication Date(Web):July 11, 2017
DOI:10.1021/acsami.7b07639
Robust, stretchable, and strain-sensitive hydrogels have recently attracted immense research interest because of their potential application in wearable strain sensors. The integration of the synergistic characteristics of decent mechanical properties, reliable self-healing capability, and high sensing sensitivity for fabricating conductive, elastic, self-healing, and strain-sensitive hydrogels is still a great challenge. Inspired by the mechanically excellent and self-healing biological soft tissues with hierarchical network structures, herein, functional network hydrogels are fabricated by the interconnection between a “soft” homogeneous polymer network and a “hard” dynamic ferric (Fe3+) cross-linked cellulose nanocrystals (CNCs–Fe3+) network. Under stress, the dynamic CNCs–Fe3+ coordination bonds act as sacrificial bonds to efficiently dissipate energy, while the homogeneous polymer network leads to a smooth stress-transfer, which enables the hydrogels to achieve unusual mechanical properties, such as excellent mechanical strength, robust toughness, and stretchability, as well as good self-recovery property. The hydrogels demonstrate autonomously self-healing capability in only 5 min without the need of any stimuli or healing agents, ascribing to the reorganization of CNCs and Fe3+ via ionic coordination. Furthermore, the resulted hydrogels display tunable electromechanical behavior with sensitive, stable, and repeatable variations in resistance upon mechanical deformations. Based on the tunable electromechanical behavior, the hydrogels can act as a wearable strain sensor to monitor finger joint motions, breathing, and even the slight blood pulse. This strategy of building synergistic “soft and hard” structures is successful to integrate the decent mechanical properties, reliable self-healing capability, and high sensing sensitivity together for assembling a high-performance, flexible, and wearable strain sensor.Keywords: dynamic coordination; hybrid network hydrogels; self-healing; strain sensing; wearable strain sensors;
Co-reporter:Ting Wang;Yunlong Guo;Xiaoming Sun;Han Zhang;Zhongzhen Yu;Xiaodong Chen
Nanoscale (2009-Present) 2017 vol. 9(Issue 2) pp:869-874
Publication Date(Web):2017/01/05
DOI:10.1039/C6NR08265C
A flexible, transparent, and portable wrist strap sensor device has been well developed from a hierarchical polydiacetylene/MoS2 nanocomposite (PDA/MoS2) film. MoS2 with a nanoflake structure and chelation ability acts as a supporter for PDA films to enhance the porosity as well as the transparency of films, which increases the sensitivity, selectivity, and application potential of a PDA sensor. The PDA/MoS2 film sensor shows a linear detection range for N,N-dimethylformamide (DMF) vapor from 0.01% to 4% with a visible blue to red color change detected by the naked eye, which is more sensitive than other organic vapors. Exploiting the high transparency, vivid color change, remarkable flexibility and reliability, a wearable wrist strap sensor device with visible DMF sensing ability is fabricated based on PDA/MoS2 films, indicating their great potential for smart wearable devices.
Co-reporter:Meihong Liao;Jiangru Wen;Min Gong;Xiaoxuan Wu;Yonggang Wang;Rui Shi;Liqun Zhang
Advanced Functional Materials 2017 Volume 27(Issue 48) pp:
Publication Date(Web):2017/12/01
DOI:10.1002/adfm.201703852
AbstractHealable, adhesive, wearable, and soft human-motion sensors for ultrasensitive human–machine interaction and healthcare monitoring are successfully assembled from conductive and human-friendly hybrid hydrogels with reliable self-healing capability and robust self-adhesiveness. The conductive, healable, and self-adhesive hybrid network hydrogels are prepared from the delicate conformal coating of conductive functionalized single-wall carbon nanotube (FSWCNT) networks by dynamic supramolecular cross-linking among FSWCNT, biocompatible polyvinyl alcohol, and polydopamine. They exhibit fast self-healing ability (within 2 s), high self-healing efficiency (99%), and robust adhesiveness, and can be assembled as healable, adhesive, and soft human-motion sensors with tunable conducting channels of pores for ions and framework for electrons for real time and accurate detection of both large-scale and tiny human activities (including bending and relaxing of fingers, walking, chewing, and pulse). Furthermore, the soft human-motion sensors can be enabled to wirelessly monitor the human activities by coupling to a wireless transmitter. Additionally, the in vitro cytotoxicity results suggest that the hydrogels show no cytotoxicity and can facilitate cell attachment and proliferation. Thus, the healable, adhesive, wearable, and soft human-motion sensors have promising potential in various wearable, wireless, and soft electronics for human–machine interfaces, human activity monitoring, personal healthcare diagnosis, and therapy.
Co-reporter:Crystal Shaojuan Luo;Hui Yang;Sayyed Asim Ali Shah;Xiaodong Chen
Advanced Functional Materials 2017 Volume 27(Issue 23) pp:
Publication Date(Web):2017/06/01
DOI:10.1002/adfm.201606339
With the advent of the digital era, healable electronic devices are being developed to alleviate the propagation of breakdown in electronics due to the mechanical damage caused by bending, accidental cutting or scratching. Meanwhile, flexible transparent electronics, exhibiting high transmittance and robust flexibility, are drawing enormous research efforts due to their potential applications in various integrated wearable electronics. However, the breakdown of flexible transparent electronics seriously limits their reliability and lifetime. Therefore, transparent healable electronics are desired to tackle these problems, yet most of the healable electronics are not transparent nowadays. The combination of high performance, healability, and transparency into electronics is often mutually exclusive. Herein, after a brief introduction of self-healing materials, healable electronics, and flexible transparent electronics, the recent progress in the healable electronic devices without transparency is reviewed in detail. Then, healable transparent electronic devices with high transparency, robust portability, and reliable flexibility are summarized. They are drawing great attention owing to their potential application in optical devices as well as smart wearable and integrated optoelectronic devices. Following that, the critical challenges and prospects are highlighted for the development of healable transparent electronic devices.
Co-reporter:Lina Xue, Wen Wang, Yunlong Guo, Guangqing Liu, Pengbo Wan
Sensors and Actuators B: Chemical 2017 Volume 244(Volume 244) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.snb.2016.12.064
•The interconnected nanocomposite networks of PANI nanoparticle-coated CNT and PANI nanofiber were obtained and deposited on PET substrates.•The assembled electronic gas sensors exhibit highly sensitive NH3 sensing from 200 ppb to 50 ppm at room temperature and reliable flexibility.•It could be attributed to the synergistic properties of the interconnected nanocomposite networks with high surface area.Real-time ammonia (NH3) detection in anaerobic digestion is highly desirable, due to the ammonia inhibition on methane production. Here, the interconnected nanocomposite network of polyaniline (PANI) nanoparticle-coated carbon nanotube (CNT) and PANI nanofiber is fabricated by adding ammonium persulfate into CNT-containing aniline solution for PANI polymerization and film deposition. The film is assembled as high-sensitive ammonia sensors, exhibiting highly sensitive NH3 sensing from 200 ppb to 50 ppm, fast response/recovery time, room-temperature operation without external aid, reliable flexibility and excellent selectivity to NH3 compared to other volatile organic compounds.A hierarchical polyaniline/carbon nanotube nanocomposite network film is fabricated and assembled as high-sensitive ammonia (NH3) sensors for potentially monitoring NH3 in anaerobic digestion. It exhibits highly sensitive NH3 sensing from 200 ppb to 50 ppm, room-temperature operation without external aid, and excellent selectivity to NH3 compared to other volatile organic compounds.Download high-res image (142KB)Download full-size image
Co-reporter:Yunlong Guo, Ting Wang, Fanhong Chen, Xiaoming Sun, Xiaofeng Li, Zhongzhen Yu, Pengbo Wan and Xiaodong Chen
Nanoscale 2016 vol. 8(Issue 23) pp:12073-12080
Publication Date(Web):19 May 2016
DOI:10.1039/C6NR02540D
A hierarchically nanostructured graphene–polyaniline composite film is developed and assembled for a flexible, transparent electronic gas sensor to be integrated into wearable and foldable electronic devices. The hierarchical nanocomposite film is obtained via aniline polymerization in reduced graphene oxide (rGO) solution and simultaneous deposition on flexible PET substrate. The PANI nanoparticles (PPANI) anchored onto rGO surfaces (PPANI/rGO) and the PANI nanofiber (FPANI) are successfully interconnected and deposited onto flexible PET substrates to form hierarchical nanocomposite (PPANI/rGO-FPANI) network films. The assembled flexible, transparent electronic gas sensor exhibits high sensing performance towards NH3 gas concentrations ranging from 100 ppb to 100 ppm, reliable transparency (90.3% at 550 nm) for the PPANI/rGO-FPANI film (6 h sample), fast response/recovery time (36 s/18 s), and robust flexibility without an obvious performance decrease after 1000 bending/extending cycles. The excellent sensing performance could probably be ascribed to the synergetic effects and the relatively high surface area (47.896 m2 g−1) of the PPANI/rGO-FPANI network films, the efficient artificial neural network sensing channels, and the effectively exposed active surfaces. It is expected to hold great promise for developing flexible, cost-effective, and highly sensitive electronic sensors with real-time analysis to be potentially integrated into wearable flexible electronics.
Co-reporter:Yingjie Li;Haichuan Zhang;Tianhao Xu;Zhiyi Lu;Xiaochao Wu;Xiaoming Sun;Lei Jiang
Advanced Functional Materials 2015 Volume 25( Issue 11) pp:1737-1744
Publication Date(Web):
DOI:10.1002/adfm.201404250
A pine-shaped Pt nanostructured electrode with under-water superaerophobicity for ultrahigh and steady hydrogen evolution reaction (HER) performance is successfully fabricated by a facile and easily scalable electrodeposition technique. Due to the lower bubble adhesive force (11.5 ± 1.2 μN), the higher bubble contact angle (161.3° ± 3.4°) in aqueous solution, and the smaller size of bubbles release for pine-shaped Pt nanostructured electrode, the incomparable under-water superaerophobicity for final repellence of bubbles from submerged surface with ease, is successfully achieved, compared to that for nanosphere electrode and for Pt flat electrode. With the merits of superior under-water superaerophobicity and excellent nanoarray morphology, pine-shaped Pt nanostructured electrode with the ultrahigh electrocatalytic HER performance, excellent durability, no obvious current fluctuation, and dramatically fast current density increase at overpotential range (3.85 mA mV−1, 2.55 and 13.75 times higher than that for nanosphere electrode and for Pt flat electrode, respectively), is obtained, much superior to Pt nanosphere and flat electrodes. The successful introduction of under-water superaerophobicity to in-time repel as-formed H2 bubbles may open up a new pathway for designing more efficient electrocatalysts with potentially practical utilization in the near future.
Co-reporter:Haichuan Zhang, Yingjie Li, Guoxin Zhang, Tianhao Xu, Pengbo Wan and Xiaoming Sun
Journal of Materials Chemistry A 2015 vol. 3(Issue 12) pp:6306-6310
Publication Date(Web):20 Feb 2015
DOI:10.1039/C5TA00707K
A CoS2 nanopyramid array with a low mass loading (∼0.625 mg cm−2) fabricated on 3D carbon fiber paper exhibits ultrahigh activity towards acidic hydrogen evolution with a low onset potential (∼61 mV) and a small overpotential (∼140 mV) for driving a current density of ∼100 mA cm−2, ascribed to the one-step solvothermal synthesis, unique 3D nanostructure and intrinsic metallic properties of the electrocatalyst.
Co-reporter:Yuhang Wang;Guoxin Zhang;Wenwen Xu; Pengbo Wan;Zhiyi Lu;Yaping Li ; Xiaoming Sun
ChemElectroChem 2014 Volume 1( Issue 7) pp:1138-1144
Publication Date(Web):
DOI:10.1002/celc.201402089
Abstract
3D Ni–Mo electrocatalysts with well-controlled composition, dimensions and nanoporosity are fabricated using a facile and effective electrodeposition technique on Cu foam. These catalysts exhibit enhanced stability and activity for the hydrogen evolution reaction (HER). By optimizing the Ni/Mo ratio, electrodeposition current density, and reaction time, the overpotential for the HER is reduced to 10 mV. The ultrahigh activity and stability of these catalysts are the highest among non-precious-metal electrocatalysts previously reported. The optimized Ni–Mo electrocatalyst has similar overpotential and a much higher current density compared to Pt/C. The improved HER performance is attributed to the Ni/Mo ratio (4:1), the large surface area, and the in situ growth method, which provides a well-defined catalyst. These catalysts are potentially an attractive alternative to Pt in HERs, and therefore represent new technological opportunities for the development of renewable and economic hydrogen production.
Co-reporter:Yuhang Wang;Guoxin Zhang;Wenwen Xu; Pengbo Wan;Zhiyi Lu;Yaping Li ; Xiaoming Sun
ChemElectroChem 2014 Volume 1( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/celc.201402180
Abstract
The front cover artwork is provided by the group of Prof. Xiaoming Sun and Prof. Pengbo Wan at Beijing University of Chemical Technology (PR China). The image shows a Ni–Mo electrocatalyst for the hydrogen evolution reaction (HER). It is revealed that the performance of the fabricated 3D Ni–Mo electrocatalyst with negligible overpotential, high current density, ultrahigh activity, and durable stability for alkaline HER, challenges that of Pt catalysts. Read the full text of the article at 10.1002/celc.201402089.
Co-reporter:Yuhang Wang;Guoxin Zhang;Wenwen Xu; Pengbo Wan;Zhiyi Lu;Yaping Li ; Xiaoming Sun
ChemElectroChem 2014 Volume 1( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/celc.201490034
Co-reporter: Pengbo Wan; Xiaodong Chen
ChemElectroChem 2014 Volume 1( Issue 10) pp:1602-1612
Publication Date(Web):
DOI:10.1002/celc.201402266
Abstract
Inspired by natural biochemical promotion and inhibition of electron-transport processes in response to real-life physical/chemical stimuli, artificial signal-triggered bioelectrocatalysis and modulation of the electron-transfer processes of redox biomolecules are vitally important for understanding electron-transport pathways in bioelectrochemical systems and for mimicking the dynamic properties of sensitive biochemical reactions in real bioprocesses. Recently, the reversible activation and deactivation of bioelectrocatalysis by external stimuli on functional electrodes integrated with redox enzymes has been established, especially at stimuli-responsive supramolecular interfaces. Potential applications in various research fields include controllable biofuel cells, bioelectronic devices, stimuli-responsive biosensors, energy transduction, information storage, and data processing. This Minireview aims to summarize the current state-of-the-art knowledge on various controllable bioelectrocatalysts from diverse functional interfaces formed by supramolecular interactions and supramolecular assemblies. The role of the assembled interface is highlighted, and the electrochemical kinetics during “on” and “off” states of bioelectrocatalysis is discussed. Finally, possible strategies for the future design of stimuli-responsive bioelectrocatalysts integrated with multifunctional supramolecular interfaces are presented.
Co-reporter:Haichuan Zhang, Yingjie Li, Guoxin Zhang, Tianhao Xu, Pengbo Wan and Xiaoming Sun
Journal of Materials Chemistry A 2015 - vol. 3(Issue 12) pp:NaN6310-6310
Publication Date(Web):2015/02/20
DOI:10.1039/C5TA00707K
A CoS2 nanopyramid array with a low mass loading (∼0.625 mg cm−2) fabricated on 3D carbon fiber paper exhibits ultrahigh activity towards acidic hydrogen evolution with a low onset potential (∼61 mV) and a small overpotential (∼140 mV) for driving a current density of ∼100 mA cm−2, ascribed to the one-step solvothermal synthesis, unique 3D nanostructure and intrinsic metallic properties of the electrocatalyst.
