ELECTROANALYSIS
·
2026
·Vol. 38
·期 6
·e70181
·
IF 2.6
Shijie Xu,Zefeng Li,Xinwei Dou,Yawen Kong,Lu Li,Xin Li,Debao Xiao
The possibility of an electrochromic platform for the visual detection of target molecule has been proven in our previous work. In this article, levodopa, which bears a phenol combined with amine, is envisaged as an extension of research. Levodopa is added into the electrolyte gel of the electrochromic devices based on benzyl viologen. We found that levodopa can improve the electrochromic performance of benzyl viologen. Levodopa reduces the driving voltage of the electrochromic device to −1.2 V, in comparison to that of −2.4 V without levodopa. The optical contrast of the device at 535 nm increases dramatically with the introduction of levodopa under the same condition. The coloration time of the device in the absence of levodopa can be shortened from 67.7 to 14.2 s with this compound, and the bleaching time decreased from 1030.4 to 874.6 s. The coloration efficiency of the as-fabricated devices at 535 nm can reach from 23.93 cm 2 ·C − 1 (benzyl viologen-only) up to 73.91 cm 2 ·C − 1 (with levodopa). It is interesting to note that the coloration of the electrochromic devices evolves as a function of the concentration of levodopa from 1.0 × 10 − 6 to 2.0 × 10 − 2 mol·L − 1 at a fixed driving voltage, giving a linear relationship between RGB chrominance values and logarithmic of levodopa concentrations, showing the possibility of electrochromic visual indication. This article demonstrates levodopa can enhance the electrochromic performance of benzyl viologen and also holds promise for visual indication of levodopa level.
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DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Jinxu Zhao,Qijun Chen,Zitao Wang,Jianming Zheng,Chunye Xu
Ionic liquids have been recognized as promising electrolytes in electrochromic devices (ECDs). However, the limited solubility of commercial electrochromic materials (ECMs) in ionic liquid effects the electrochromic performance of ECDs. This work synthesized viologen-type (Vio-IL) and ferrocene-type (Fc-IL) room-temperature ionic liquids (RTILs), which have melting points of −22.5 °C and −43.6 °C, respectively. ECDs prepared using these two RTILs exhibit superior optical modulation ability (ΔT = 79.4 %) and good cyclic stability (1000cycles 96.2 %). These two RTILs exhibit advantages because they can be miscible with commonly ionic liquids solvent. Further, ultra-thin (10 μm) ECDs prepared using these RTILs with 20 wt% ionic liquid diluent not only have good electrochromic performance (ΔT = 73.1 %, 1000cycles 95.6 %, 3.7 s for coloring and 13.3 s for bleaching) but also have a wide temperature working window (−30°C–70 °C). These ultra-thin and low-solvent ECDs have the potential to enable temperature adaptability and lightweight and eco-friendly smart windows.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 9
·3654-3663
·
IF 3.288
Dong-Mei Ma,Jing Wang,Hao Guo,Dong-Jin Qian
Thioxanthones (TXs) and viologens (VIOs) are important photo-sensitizers and electron mediators with interesting opto-electrochemical properties and potential applications for novel opto-electrical devices, displays, switches and sensors. Here, we reported the photophysical and electrochemical properties of newly synthesized TX–VIO binary derivatives, and their photo-/electrochromic displays in the ionic liquids and polymer gels. The precursor of TXBr (without the VIO substituent) gave off a blue light emission centered at about 437 nm with a quantum efficiency (QE) of approximately 0.2. For TX-VIOs, their QE was below 0.01; this significant luminescent quenching was attributed to an intramolecular energy transfer from the excited singlet state of TX to electroactive VIO. Thus, these TX–VIOs displayed good photochromic behaviors under ultraviolet and/or visible light radiation. Cyclic voltammograms of TX–VIOs showed two couples of chemically reversible waves centered at approximately −0.43 and −0.90 V (vs. Hg/Hg2Cl2). The former one was attributed to the electron transfer process of TX–VIO2+ ↔ TX–VIO+˙, and the latter one to that of TX–VIO+˙ ↔ TX–VIO0 together with that of TX(red)–VIO2+ ↔ TX(ox)–VIO2+. Finally, sandwiched types of transparent and flexible photo- and electrochromic devices were constructed with the use of TX–VIOs in the ionic liquids and polymeric gels as the light-sensitizer and color display layer. These devices displayed a good transmittance and good reversible color (pink, blue and colorless) change behavior under visible light radiation or an applied bias of −2.4 V.
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高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 28
·9570-9577
·
IF 6.4
Na Chen,Wan-Xiong Yong,Tuo-Dong Xiong,Guo-Dong Fu
The development of viologen-based photochromic composite materials with a fast response to ultraviolet light has become a major research focus. In this paper, we fabricated viologen-based composite films with excellent durability and rapid photochromic performance by the solution casting method. The films changed color within one second when exposed to ultraviolet light (3 W, 365 nm). This was because ZnO NPs photogenerated electrons that enhanced the photoreduction of viologens with matched energy bands. The decoloration process of the films could be regulated by different moisture levels while keeping their photochromic properties unaffected. Moreover, the films exhibited less than 15% change in absorbance over 20 repeated coloring and fading cycles. Therefore, the excellent photoresponsiveness, repeatability and environmental friendliness of the films provide them potential for applications in areas such as rewritable paper, solar UV detection, smart windows and anti-counterfeiting.
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2023
·
IF 4.6
Fangyuan Sun,He Zhang,Cong Wang,Huan Ling,Jiayi Cai,Weilun Peng,Yanhong Tian,Fengyu Su,Yanqing Tian,Yan Jun Liu
Viologen-based electrochromic devices (ECDs) have attracted considerable attention due to their potential applications in smart windows. Herein, two viologen derivatives with N-substituted monohexyl ( MHEV ) and dihexyl ( DHEV ), and two extended viologen derivatives with a thiophene unit inserted between the bipyridine moieties and N-substituted monohexyl ( m-MHEV ) and dihexyl ( m-DHEV ) were synthesized. All-in-one ECDs were assembled using these materials. m-DHEV and m-MHEV- based ECDs exhibited red and dark orange colors, while DHEV and MHEV- based ECDs exhibited blue and magenta colors. The extended conjugation of the chromophore by the thiophene unit endowed the devices with visible-NIR absorption and excellent cyclic stability. After 10000 cycles, ECDs based on m-DHEV and m-MHEV retained 94.2% and 95.0% of their initial optical contrasts, respectively. A binary chromophore mixture of DHEV and m-DHEV was used to fabricate a uniform large-area ECD (8 cm × 8 cm) with strong sunlight absorption ability. The device maintained high optical contrast (80.2% of initial state) after 2000 cycles. Furthermore, a solar cell powered ECD (8 cm × 8 cm) with negligible loss of optical contrast after 100 cycles of coloring and bleaching under sunlight was developed, demonstrating the application potential of self-powered smart windows using these materials.
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高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2026
·
IF 3.2
Xiaonan Li,Xirong Huang
Abstract An oil-in-water microemulsion is an excellent candidate medium for the electrochemical regeneration of the coenzyme NADH and its subsequent coupled conversion application due to its good electrical conductivity and solubilization capacity for hydrophobic substrates. In this work, the reduced methyl viologen (MV+•)-mediated electrochemical reduction of coenzyme NAD+ was studied in a Triton X-100 (TX-100)-stabilized methyl tert-butyl ether (MTBE)-in-water microemulsion. The effects of the surfactant concentration and the oil content on the electrochemical behavior of the MV2+/MV+• couple and the activity of diaphorase (DH) were systematically investigated. The results show that in the microemulsion, the couple exhibits excellent reversibility. Compared with the aqueous buffer system, the couple in the microemulsion system has a more positive formal potential and a lower redox peak current, depending on the levels of both the surfactant and the oil. The positive shift of the formal potential is attributed to the stabilizing effect of the surfactant aggregates on the relatively hydrophobic MV+• species, and the decrease of the redox currents is ascribed to the decrease of the electroactive area of the electrode due to the adsorption of the surfactant and the oil as well as the decrease of the diffusion coefficients of MV species associated with or solubilized in the surfactant aggregates. The activity of DH in the microemulsion system also depends on the TX-100 concentration and the MTBE content. Increases in both [TX-100] and [MTBE] result in a decrease in DH activity. This phenomenon could be explained based on the [TX-100]/[MTBE]-dependent changes in the local acidity and the local concentration of the substrate DCPIP in the microemulsions. Based on cyclic voltammetry, the MV+•-mediated electroreduction of NAD+ in the TX-100-stabilized MTBE/H2O (0.1 M PB, pH = 7.0) microemulsion was studied. For the microemulsion system containing 0.5 mM MV2+, 5 mM NAD+, and 26.6 μM DH, when a scan rate of 2 mV s–1 was applied, a typical steady-state S-shaped CV curve was obtained. UV–vis spectroscopy confirms that the NADH generated by the mediated reaction is bioactive. By coupling the MV+•-mediated NADH electrochemical regeneration reaction with the horse liver alcohol dehydrogenase (HLADH)-catalyzed reduction of the hydrophobic substrate 4-phenyl-2-butanone, the enantiomerically pure (S)-4-phenyl-2-butanol can be selectively obtained. After 12 h, the yield of the product in the microemulsion is approximately 10 times that in the DMSO-buffer mixed homogeneous system. This difference in yield is caused by the differences in enzyme activity and stability, as well as in the substrate local concentration and reactivity in the two systems. The present study indicates that the TX-100-stabilized MTBE-in-water microemulsion is a suitable medium for the electrochemical regeneration of NADH and the electroenzymatic conversion of water-insoluble substrates catalyzed by NADH-dependent oxidoreductases.
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高影响因子
BIOSENSORS & BIOELECTRONICS
·
2021
·
IF 10.618
Zipin Zhang,Rui Zhou,Yongliang Dong,Mengmeng Song,Lei Tian,Zuzhi Zhao
We have reported an optical indicator displacement assay (IDA) for heparin with a UV–vis absorbance and fluorescence dual-readout based on pyranine/methyl viologen (MV 2+ ). Upon introducing heparin, pyranine/MV 2+ shows a clearly observable increase in UV–vis absorbance and a turn-on of the fluorescence signal. We have demonstrated that the ionic nature of buffers significantly affects the pyranine displacement and the zwitterionic HEPES was most suitable for heparin sensing. After careful screening of experimental conditions, the pyranine/MV 2+ -based optical chemosensor exhibits a fast, sensitive, and selective response toward heparin. It shows dynamic linear concentration of heparin in the ranges of 0.1–40 U·mL −1 and 0.01–20 U·mL −1 for the absorptive and fluorescent measurements, respectively, which both cover the clinically relevant levels of heparin. As with the animal experiments, the optical chemosensor has been demonstrated to be selective and effective for heparin level qualification in rat plasma. The chemosensor is readily accessible, cost-effective, and reliable, which holds a great promise for potential application on clinical and biological studies. Furthermore, this IDA system can serve as an IMPLICATION logic gate with a reversible and switchable logical manner.
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PubMed
高影响因子
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