Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,t...Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.展开更多
This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes.Thin films of vinyl-functionalized diruthenium or ruthenium-amine con...This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes.Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization.The resulting films are useful for multistate near-infrared electrochromism,ion sensing,and mimicking flip-flop and flip-flap-flop logic gates.The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit.The applications of the resulting films in multistate near-infrared electrochromism and resistive memory are discussed.展开更多
Poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate）（PEDOT：PSS） is usually sandwiched between indium tin oxide（ITO） and a functional polymer in order to improve the performance of the device. However, bec...Poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate）（PEDOT：PSS） is usually sandwiched between indium tin oxide（ITO） and a functional polymer in order to improve the performance of the device. However, because of the strong acidic nature of PEDOT：PSS, the instability of the ITO/PEDOT：PSS interface is also observed. The mechanism of degradation of the device remains is unclear and needs to be further studied. In this article, we investigate the in-situ electrochromism of PEDOT：PSS to disclose the cause of the degradation. X-ray photoelectron spectroscopy（XPS） was used to characterize the PEDOT：PSS films, as well as the PEDOT：PSS plus polyethylene glycol（PEG） films with and without indium ions. The electrochromic devices（ECD） based on PEDOT：PSS and PEG with and without indium ions are carried out by in-situ micro-Raman and laser reflective measurement（LRM）. For comparison, ECD based on PEDOT：PSS and PEG films with LiCl, KCl, NaCl or InCl_3 are also investigated by LRM. The results show that PEDOT：PSS is further reduced when negatively biased, and oxidized when positively biased. This could identify that PEDOT：PSS with indium ions from PEDOT：PSS etching ITO will lose dopants when negatively biased. The LRM shows that the device with indium ions has a stronger effect on the reduction property of PEDOT：PSS-PEG film than the device without indium ions. The contrast of the former device is 44%, that of the latter device is about 3%. The LRM also shows that the contrasts of the device based on PEDOT：PSS＋PEG with LiCl, KCl, NaCl, InCl_3 are 30%, 27%, 15%, and 18%, respectively.展开更多
Electrochromic and auto-bleaching processes at the WO2 anodic film in 0. 5 mol/L H2SO4 solution were investigated by cyclic voltammetry, a. c. impedance technique and photocurrent spectrometry. The colouration mechani...Electrochromic and auto-bleaching processes at the WO2 anodic film in 0. 5 mol/L H2SO4 solution were investigated by cyclic voltammetry, a. c. impedance technique and photocurrent spectrometry. The colouration mechanism consists of hydrogen adsorption on the WO2 surface and the transport of H atoms in the WO, lattice. The bleaching process involves at least two steps: transport of interstitial H atoms and hydrogen desorption on the W surface, resulting in interstitial H+ ions; then extration of the H+ ions driven by the external electric field. The auto-bleaching arises from the hydroxylation due to both partial interstitial H atoms and a little of water contained in the film.展开更多
In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2...In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2[OTf^(–)]with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states.The inclusion of an anthracene unit as theπ-linker contributes to its exceptional redox and optoelectronic characteristics.Consequently,1^(2+)·2[OTf^(–)]was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time,and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions.展开更多
Pyrochlore-type WO3 powder was synthesized via hydrothermal method using aqueous sodium tungstate solution and oxalic acid as raw materials. The as-prepared powder was made into a soliquoid, from which films were made...Pyrochlore-type WO3 powder was synthesized via hydrothermal method using aqueous sodium tungstate solution and oxalic acid as raw materials. The as-prepared powder was made into a soliquoid, from which films were made by dip coating process with indium-tin oxide （ITO）. The obtained films were characterized by thermogravimetric and differential thermal analysis （TG-DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, cyclic voltammetry （CV）, chronoamperometry （CA） and ultraviolet- visible （UV-Vis） absorption. Results show that the crystal of the pyrochlore-type WO3 powder is perfect. When the calcination temperature rises from room temperature to 500℃, the pyrochlore-type structure first becomes deformed, then it is destroyed and turns into amorphous phase, finally it will completely convert to WO3 with a monoclinic structure. Electrochemical and optical tests demonstrate that the film calcined at 300℃ exhibits the best electrochromic performance and has a coloration efficiency of up to 68.5 cm^2-C^-1 at 884 nm.展开更多
Electrochromic materials change color or opacity when subjected to electrical stimuli,often through reversible chemical reactions or phase transitions.Their optical switch capabilities make them promising for applicat...Electrochromic materials change color or opacity when subjected to electrical stimuli,often through reversible chemical reactions or phase transitions.Their optical switch capabilities make them promising for applications like smart windows and glasses,thus garnering widespread attention in recent years.Van der Waals layered ferroelectric α-In_(2)Se_(3),known for its rich polymorphs,is a promising candidate for exploring physical property modulation via phase transformations.However,the discovery of electrochromism in In_(2)Se_(3) has been impeded by similar optical constants among its polymorphs.Herein,we report the experimental observation of reversible electrochromism in α-In_(2)Se_(3) thin flakes accompanied by ferroelectric polarization switching.Microscopic structural characterizations reveal that the color change stems from a crystalline-to-amorphous phase transition.An improved Kramer-Kronig analysis was employed to quantify the change in optical constants of the flake.A disordered polarization switching model,inherent to the crystal symmetry of α-In_(2)Se_(3),was proposed to explain the electrically driven amorphization.This work delivers distinct insight into the unique electrochromic behavior and unveils opportunities of relevant applications for the van der Waals layered ferroelectric.展开更多
To enhance the bonding strength between the active material and the core yarn current collector through nano-entanglement,bacterial cellulose/carbon nanotube(BC/CNT)nanofiber yarns were developed using in situ cultiva...To enhance the bonding strength between the active material and the core yarn current collector through nano-entanglement,bacterial cellulose/carbon nanotube(BC/CNT)nanofiber yarns were developed using in situ cultivation and wet twisting.This method utilizes the large specific surface area and abundant active functional groups of BC-based nanofibers.Subsequently,V2O5/BC/CNT composite yarn electrodes were fabricated,exhibiting a core-sheath structure with excellent conformal characteristics.The influence of ultrasound duration on the conductivity and electrochromic performance of composite yarns was investigated.The initial discharge-specific capacity was recorded as 105.3 mAh/g,with a capacity retention rate of 60.2%after 100 cycles.The composite yarn exhibited 100 reversible transitions between yellow and blue,with reduction and oxidation response times of 2.35 s and 3.3 s,respectively.The modulation amplitude at 532 nm during the initial cycle was 20.31%,and after 100 cycles,the modulation amplitude retention rate remained at 68%.展开更多
The linkage-conversion synthesis was employed for the development of low-voltage near-infrared(NIR)electrochromic aminelinked covalent organic frameworks(COFs),enabling the sophisticated display of NIR concealed infor...The linkage-conversion synthesis was employed for the development of low-voltage near-infrared(NIR)electrochromic aminelinked covalent organic frameworks(COFs),enabling the sophisticated display of NIR concealed information.Two COF systems containing triphenylamine units connected by conjugated imine bonds were transformed into conjugation-broken amine-linked COFs through linkage reduction,allowing for precise modulation of their electrochemical and electrochromic properties.The electrochemical oxidation onset potential of the amine-linked COF film was significantly reduced by approximately 0.6 V,and their absorption in the NIR region exhibits a marked enhancement and blue shift during electrochemical oxidation.Combining experimental and computational approaches,this phenomenon was attributed the previously unreported short-range charge interactions between triphenylamine and adjacent amine groups.The amine-linked COFs exhibit low electrochromic driving voltages(0.2 V),sub-second response times,high coloration efficiency,and stable electrochromic-switch properties.Notably,the low-voltage-driven amine-linked COFs showed pronounced NIR color changes with non-apparent visible color changes,leveraging this characteristic to achieve concealed information display in the NIR region.This work demonstrates the importance of linkage engineering in the design and preparation of high-quality optoelectronic functional COF materials and highlights the great application potential of optoelectronic COFs.展开更多
A cyclometalated diruthenium complex 2 bridged by 1,2,4,5-tetra(pyrid-2-yl)benzene with six carboxylic acid groups at two ends was synthesized.Monolayer and multilayer films FTO/TiO2/(2)n(Zr)(n=1,2)and FTO/SnO2:Sb/(2)...A cyclometalated diruthenium complex 2 bridged by 1,2,4,5-tetra(pyrid-2-yl)benzene with six carboxylic acid groups at two ends was synthesized.Monolayer and multilayer films FTO/TiO2/(2)n(Zr)(n=1,2)and FTO/SnO2:Sb/(2)n(Zr)(n=1-4)have been prepared via interfacial layer-by-layer coordination assembly of 2 with zirconium(IV)ions.All films show two consecutive redox couples in the potential range between 0 and+1.0 V vs.Ag/AgCl.These films exhibit reversible near-infrared electrochromism upon switching of redox potential.The response time of the films on SnO2:Sb is around a few seconds,while that on TiO2 is around a few tens of seconds.The film deposition cycles were found to have a great impact on the electrochromic performance.Among six films examined,the two-layered film on SnO2:Sb displays the best balanced performance with a contrast ratio of 56%at 1,150 nm and good cyclic stability(9%loss of contrast ratio after 1,000 continuous double-potential-switching cycles),which is superior to that of the previously reported electropolymerized films of a related diruthenium complex with the same bridging ligand.In addition,the X-ray photoelectron spectroscopy,scanning electron microscopy,and electron transfer mechanism of these films have been investigated.展开更多
Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate sma...Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate smart sensors with high robustness,reliability,and visible readout.Herein,high-performance electrochromic(EC),electro-fluorochromic(EFC),and double-network ionogels with excellent transmissivity,high mechanical robustness,and ultrastable reversibility are prepared by combination of thienoviologen-containing ionic liquids with poly(ethyl acrylate)elastomer.The ionogels exhibit good mechanical properties(1000%stretchability and 3.2 kJ m^(−2) fracture energy).The ionogel-based EC devices have a significantly simplified device fabrication process as well as superior cycling stability in which 88%of the contract ratio is maintained at 88%at 500 cycles,even after being stored for 2 years under ambient atmosphere(relative humidity:30%∼40%,25°C).The conductivity of ionogels showed a fast and reproducible response to strain,and the conductivity decreased with increased strain.By virtue of the EC and EFC properties of the thienoviologen component,the EC and EFC efficiency decreased with the increased strain loaded on the ionogels,and almost no EC or EFC phenomena were observed when the strain was above 300%.This feasible strategy provides an opportunity for the development of visible strain sensors to monitor the body’s movements through color and fluorescence emission.展开更多
Doping plays an essential role in the properties of conducting polymers.Film thickness not only has a direct influence on their photoelectric properties,but also affects the doping ability,which may lead to the declin...Doping plays an essential role in the properties of conducting polymers.Film thickness not only has a direct influence on their photoelectric properties,but also affects the doping ability,which may lead to the decline of capacitance and electrochromic properties caused by incomplete doping.Therefore,it is essential to study the quantitative relationship between doping level and film thickness in application.Herein,empirical formula between doping level and thickness was obtained by studying the spectroelectrochemistry behaviors of two different electrochromic materials,poly(N,N'-bis(3,5-(2-thienyl)-phenyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-perylenetetracarboxylic diimide)(poly(Th-Cl-PBI))and poly(3,4-ethylenedioxythiophene)(PEDOT).The doping level is verified to be correlated to the reciprocal of the 3^(rd)power of film thickness.Experimental results fit these formulas very well,giving correlation coefficient R^(2)higher than 0.99.The optical contrast prediction of these two electrochromic materials is also used to verify this relationship formula.For the first time,we quantitatively connect these two important parameters of conducting polymers,doping level and thickness.展开更多
Cyclopentadithiophene(CPDT)-based polymers have emerged as promising research platforms for multi⁃color electrochromic materials due to their favorable color tunability.However,insufficient cyclic stability has hinder...Cyclopentadithiophene(CPDT)-based polymers have emerged as promising research platforms for multi⁃color electrochromic materials due to their favorable color tunability.However,insufficient cyclic stability has hindered their translation into practical applications.In this study,two CPDT-based conjugated polymers with distinct substituent groups were designed and synthesized:PCPDT-Ph(copolymerized with unsubstituted benzene units)and PCPDT-PhOMe(copolymerized with dimethoxy-substituted benzene units).The influence of dimethoxy substitution on the electrochromic properties and stability of the polymers was systematically investigated.Electro⁃chemical and electrochromic characterizations demonstrated that the electron-donating ability of the dimethoxy groups not only effectively regulated the polymer’s intrinsic properties but also significantly enhanced its cycling stability.Compared with PCPDT-Ph,PCPDT-PhOMe exhibited a reduced onset oxidation potential from 0.66 V(vs.Ag/AgCl)to 0.46 V,an upshifted highest occupied molecular orbital(HOMO)energy level,and a narrowed optical band gap(calculated theoretically)from 1.73 eV to 1.61 eV.The PCPDT-PhOMe film showed magenta in the neutral state and transparency in the oxidized state,with a color difference(ΔE*a b)of 46.36.The coloring/bleaching response times were measured as 0.7/0.6 s,and the optical contrast retention reached 84%after 1000 cycles,outperforming the PCPDT-Ph film(79.5%retention after 500 cycles).Additionally,it exhibited a coloration efficiency of 543.9 cm^(2)/C,demonstrating favorable comprehensive electrochromic performance.Electrochromic devices assembled with PCPDT-PhOMe achieved reversible switching between magenta and transparent states,with a response time of≤1.0 s and a contrast retention of 71%after 30000 cycles,indicating good stability.This work clarifies the role of substituent electronic effects in regulating the electrochromic properties of CPDT-based polymers,providing experimental basis and theoretical support for the molecular design of solution-processable thiophene-based electrochromic materials.Furthermore,it validates the potential application of PCPDT-PhOMe in smart windows,electronic displays,and other related fields.展开更多
Two viologen derivatives containing fluorine substituent(F)with an asymmetric structures,1,1'-bis(4-(trifluoromethyl)phenyl)-[4,4'-bipyridine]dihexafluorophosphate(DFPV)and 1-benzyl-1'-(4-(trifluoromethyl)...Two viologen derivatives containing fluorine substituent(F)with an asymmetric structures,1,1'-bis(4-(trifluoromethyl)phenyl)-[4,4'-bipyridine]dihexafluorophosphate(DFPV)and 1-benzyl-1'-(4-(trifluoromethyl)phenyl)-[4,4'-bipyridine]di-hexafluorophosphate(Bn-FPV),were synthesized.These viologen derivatives as active materials were used to assemble both flexible and rigid electrochromic devices(ECDs).ECDs based on DFPV exhibited reversible color change from colorless to deep green and ECDs based on Bn-FPV exhibited reversible color change from colorless to blue-green within applied voltage.It was found that the devices based on DFPV showed cycle stability,which could still maintain more than 90% after 1000 cycles.In addition,the modulation rate of the device to the solar irradiance is also calculated to characterize its application potential in smart windows.Among them,the rigid device(R-DFPV)based on the DFPV has a large solar irradiance modulation rate of 54.66%,which has the potential to be used as smart windows.展开更多
With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial c...With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial component of electrochromic devices(ECDs),show great promise in applications.This is attributed to their efficient ion-transport capabilities,excellent mechanical properties and strong adhesion.All of these characteristics are conducive to enhancing the safety of the devices,streamlining the packaging process,significantly improving the electrochromic performance of ECDs and boosting their commercial application potential.This review provides a comprehensive overview of GPEs for ECDs,focusing on their basic designs,functional modifications and practical applications.Firstly,this review outlines the fundamental design of GPEs for ECDs,encompassing key performance index,classification,gelation mechanism and preparation methods.Building on this foundation,it provides an in-depth discussion of functionalized GPEs developed to enhance device performance or expand functionality,including electrochromic,temperature-responsive,photo-responsive and stretchable self-healing GPE.Furthermore,the integration of GPEs into various ECD applications,including smart windows,displays,energy storage devices and wearable electronic,are summarized to highlight the advantages that the design of GPEs brings to the practical application of ECDs.Finally,based on the summary of GPEs employed for ECDs,the challenges and development expectations in this direction were indicated.展开更多
Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive exa...Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive examination of curtain walls from an energy-engineering perspective,highlighting their structural typologies(Stick and Unitized),material configurations,and integration with smart technologies such as electrochromic glazing,parametric design algorithms,and Building Management Systems(BMS).Thestudy explores the thermal,acoustic,and solar performance of curtain walls across various climatic zones,supported by comparative analyses and iconic case studies including Apple Park,Burj Khalifa,and Milad Tower.Key challenges—including installation complexity,high maintenance costs,and climate sensitivity—are critically assessed alongside proposed solutions.A central innovation of this work lies in framing curtain walls not only as passive architectural elements but as dynamic interfaces that modulate energy flows,reduce HVAC loads,and enhance occupant comfort.The reviewed data indicate that optimized curtain wall configurations—especially those integrating electrochromic glazing and BIPV modules—can achieve annual energy consumption reductions ranging fromapproximately 5%to 27%,depending on climate,control strategy,and facade typology.The findings offer a valuable reference for architects,energy engineers,and decision-makers seeking to integrate high-performance facades into future-ready building designs.展开更多
Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero ...Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.展开更多
Prussian blue(PB)is an anodic coloring candidate in the wide area of electrochromic(EC)applications.However,the co-influence of weak adhesion and low electrical conductivity leads to the poor stability and slow switch...Prussian blue(PB)is an anodic coloring candidate in the wide area of electrochromic(EC)applications.However,the co-influence of weak adhesion and low electrical conductivity leads to the poor stability and slow switching speed.To tackle this bottleneck,a novel TiO_(2)/Au/PB nanorod array is designed through hydrothermal and electrodeposition approaches on fluorine-doped tin oxide(FTO)glass.Such a designed ternary array structure could not only increase reactive site and conductivity,but also improve ion storage capacity and promote charge transfer,attributed to the synergistic effect of TiO_(2)/Au/PB core–shell heterostructure and the localized surface plasmon resonance(LSPR)effect of Au nanoparticles.Besides,density functional theory(DFT)calculation confirms the strong interaction between rutile TiO_(2)and FTO substrate,which contributes to the improvement of EC cycle stability.Benefiting from these effects,the TiO_(2)/Au/PB film shows a fast coloration/bleaching response of 1.08/2.01 s(2.17/4.48 s,PB film)and ultra-stable EC performance of 86.8%after 20,000 cycles(50%after 600 cycles,PB film).Furthermore,the high-intensity light source can be shot clearly by the designed and assembled EC iris device(ECID)with TiO_(2)/Au/PB film as an EC layer,while the photograph without an ECID is blurry,confirming the feasibility of the material in portable digital products.展开更多
In our work,polymorphism strategy has been successfully applied to tune up chromism and luminescence properties of viologen-based materials.Two polymorphs of viologen-based complexes ofα-CdBr_(2)(PHSQ)_(2)(H_(2)O)_(2...In our work,polymorphism strategy has been successfully applied to tune up chromism and luminescence properties of viologen-based materials.Two polymorphs of viologen-based complexes ofα-CdBr_(2)(PHSQ)_(2)(H_(2)O)_(2)(1)andβ-CdBr_(2)(PHSQ)_(2)(H_(2)O)_(2)(2)(PHSQ=N-(4-sulfophenyl)-4,4-bipyridinium)were synthesized by changing the solvent.They can both respond to UV light and electricity in the manner of chromism visible to the naked eye and the coloration states have good reversibility,through which an inkless erasable printing model has been established.But the coloration contrast of 1 is higher compared to 2.Meanwhile,they both exhibit photoluminescence properties and the intensity of 1 is twice that of 2,which is accompanied by photoquenching upon continuous UV light irradiation.The only divergence of disordered/ordered O atoms in the two crystalline compounds leads to significantly different chromic and luminescent properties.Further explorations simultaneously demonstrate that the different chromic performance between 1 and 2 should attribute to the alteration of stimulus-induced(light/electricity)electron transfer channels caused by the ordered/disordered O atoms in the complexes,which is achieved through C-H···O and O-H···O interactions to change crystal arrangement and structural rigidity,thus affect luminescent properties.展开更多
This paper adopted the hydrothermal method to prepare tungsten oxide(WO_(3))nanorod films and studied the effects of precursor solution concentration(0.02,0.03,0.06 mol/L peroxytungstic acid)and annealing temperature(...This paper adopted the hydrothermal method to prepare tungsten oxide(WO_(3))nanorod films and studied the effects of precursor solution concentration(0.02,0.03,0.06 mol/L peroxytungstic acid)and annealing temperature(200,300,400℃)on their electrochromic properties.The microstructure characterization of WO_(3) films were performed using scanning electron microscope(SEM),X-ray diffraction(XRD),and transmission electron microscope(TEM),and their electrochromic properties were tested by combining an electrochemical workstation with an ultraviolet-visible spectrophotometer.The results showed that the precursor solution concentration directly affected the thickness(290,560,990 nm)and microstructure of WO_(3) films,significantly impacting their electrochromic properties.However,the annealing temperature had a negligible effect.As the precursor solution concentration increased,the optical modulation of WO_(3) films gradually decreased,reaching 51.1%,43.8%,and 35.1%,respectively.The switching time first increased and then stabilized,with coloring times of 7.3,7.7,and 7.7 s,respectively,and bleaching times of 3.8,6.5,and 6.5 s,respectively.The coloration efficiency gradually increased but the increase was relatively small,reaching 41.8,44.4,and 44.8 cm^(2)/C,respectively.Moreover,the cycling stability of WO_(3) films was poor,with the ratios of the final value of optical modulation to the initial value 0.33,0.26,and 0.34,respectively.Additionally,there were bigger differences in the bleached state transmittance,while the colored state transmittance showed smaller variations.However,the former has better cycling stability than the latter.In summary,to obtain better electrochromic properties,the thickness of WO_(3) films should not exceed 290 nm.展开更多
基金Supported by Jilin Provincial Scientific and Technological Development Program(20230508109RC,20230201051GX,20220201091GX)National Natural Science Foundation of China(62035013,61275235)。
文摘Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.
基金the National Natural Science Foundation of China(Nos.21271176,21472196,21521062,and 21501183)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 12010400)for funding support
文摘This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes.Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization.The resulting films are useful for multistate near-infrared electrochromism,ion sensing,and mimicking flip-flop and flip-flap-flop logic gates.The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit.The applications of the resulting films in multistate near-infrared electrochromism and resistive memory are discussed.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA034201)the Chinese Universities Scientific Fund(Grant No.2015LX002)
文摘Poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate）（PEDOT：PSS） is usually sandwiched between indium tin oxide（ITO） and a functional polymer in order to improve the performance of the device. However, because of the strong acidic nature of PEDOT：PSS, the instability of the ITO/PEDOT：PSS interface is also observed. The mechanism of degradation of the device remains is unclear and needs to be further studied. In this article, we investigate the in-situ electrochromism of PEDOT：PSS to disclose the cause of the degradation. X-ray photoelectron spectroscopy（XPS） was used to characterize the PEDOT：PSS films, as well as the PEDOT：PSS plus polyethylene glycol（PEG） films with and without indium ions. The electrochromic devices（ECD） based on PEDOT：PSS and PEG with and without indium ions are carried out by in-situ micro-Raman and laser reflective measurement（LRM）. For comparison, ECD based on PEDOT：PSS and PEG films with LiCl, KCl, NaCl or InCl_3 are also investigated by LRM. The results show that PEDOT：PSS is further reduced when negatively biased, and oxidized when positively biased. This could identify that PEDOT：PSS with indium ions from PEDOT：PSS etching ITO will lose dopants when negatively biased. The LRM shows that the device with indium ions has a stronger effect on the reduction property of PEDOT：PSS-PEG film than the device without indium ions. The contrast of the former device is 44%, that of the latter device is about 3%. The LRM also shows that the contrasts of the device based on PEDOT：PSS＋PEG with LiCl, KCl, NaCl, InCl_3 are 30%, 27%, 15%, and 18%, respectively.
基金The project Supported by National Natural Science Foundation of China.
文摘Electrochromic and auto-bleaching processes at the WO2 anodic film in 0. 5 mol/L H2SO4 solution were investigated by cyclic voltammetry, a. c. impedance technique and photocurrent spectrometry. The colouration mechanism consists of hydrogen adsorption on the WO2 surface and the transport of H atoms in the WO, lattice. The bleaching process involves at least two steps: transport of interstitial H atoms and hydrogen desorption on the W surface, resulting in interstitial H+ ions; then extration of the H+ ions driven by the external electric field. The auto-bleaching arises from the hydroxylation due to both partial interstitial H atoms and a little of water contained in the film.
基金supported by Natural Science Foundation of China(Nos.22001200,22175138,21875180)。
文摘In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2[OTf^(–)]with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states.The inclusion of an anthracene unit as theπ-linker contributes to its exceptional redox and optoelectronic characteristics.Consequently,1^(2+)·2[OTf^(–)]was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time,and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions.
基金financially supported by the National Natural Science Foundation of China (No. 51274243)the Project of Innovation-Driven Plan in Central South University, China (No. 2015CX001)
文摘Pyrochlore-type WO3 powder was synthesized via hydrothermal method using aqueous sodium tungstate solution and oxalic acid as raw materials. The as-prepared powder was made into a soliquoid, from which films were made by dip coating process with indium-tin oxide （ITO）. The obtained films were characterized by thermogravimetric and differential thermal analysis （TG-DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, cyclic voltammetry （CV）, chronoamperometry （CA） and ultraviolet- visible （UV-Vis） absorption. Results show that the crystal of the pyrochlore-type WO3 powder is perfect. When the calcination temperature rises from room temperature to 500℃, the pyrochlore-type structure first becomes deformed, then it is destroyed and turns into amorphous phase, finally it will completely convert to WO3 with a monoclinic structure. Electrochemical and optical tests demonstrate that the film calcined at 300℃ exhibits the best electrochromic performance and has a coloration efficiency of up to 68.5 cm^2-C^-1 at 884 nm.
基金the National Natural Science Foundation of China(12074278)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe support from Suzhou Science and Technology Bureau(ZXL2022514).
文摘Electrochromic materials change color or opacity when subjected to electrical stimuli,often through reversible chemical reactions or phase transitions.Their optical switch capabilities make them promising for applications like smart windows and glasses,thus garnering widespread attention in recent years.Van der Waals layered ferroelectric α-In_(2)Se_(3),known for its rich polymorphs,is a promising candidate for exploring physical property modulation via phase transformations.However,the discovery of electrochromism in In_(2)Se_(3) has been impeded by similar optical constants among its polymorphs.Herein,we report the experimental observation of reversible electrochromism in α-In_(2)Se_(3) thin flakes accompanied by ferroelectric polarization switching.Microscopic structural characterizations reveal that the color change stems from a crystalline-to-amorphous phase transition.An improved Kramer-Kronig analysis was employed to quantify the change in optical constants of the flake.A disordered polarization switching model,inherent to the crystal symmetry of α-In_(2)Se_(3),was proposed to explain the electrically driven amorphization.This work delivers distinct insight into the unique electrochromic behavior and unveils opportunities of relevant applications for the van der Waals layered ferroelectric.
基金the National Natural Science Foundation of China(22305206)Autonomous Region Natural Science Foundation(202110120008).
文摘To enhance the bonding strength between the active material and the core yarn current collector through nano-entanglement,bacterial cellulose/carbon nanotube(BC/CNT)nanofiber yarns were developed using in situ cultivation and wet twisting.This method utilizes the large specific surface area and abundant active functional groups of BC-based nanofibers.Subsequently,V2O5/BC/CNT composite yarn electrodes were fabricated,exhibiting a core-sheath structure with excellent conformal characteristics.The influence of ultrasound duration on the conductivity and electrochromic performance of composite yarns was investigated.The initial discharge-specific capacity was recorded as 105.3 mAh/g,with a capacity retention rate of 60.2%after 100 cycles.The composite yarn exhibited 100 reversible transitions between yellow and blue,with reduction and oxidation response times of 2.35 s and 3.3 s,respectively.The modulation amplitude at 532 nm during the initial cycle was 20.31%,and after 100 cycles,the modulation amplitude retention rate remained at 68%.
基金supported by the National Natural Science Foundation of China(22005312,22375042)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB0520201)+3 种基金the Southeast University Interdisciplinary Research Program for Young Scholars(2024FGC1007)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2023QNRC001)the support of 1W1A endstation at Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciencessupported by the Big Data Computing Center of Southeast University。
文摘The linkage-conversion synthesis was employed for the development of low-voltage near-infrared(NIR)electrochromic aminelinked covalent organic frameworks(COFs),enabling the sophisticated display of NIR concealed information.Two COF systems containing triphenylamine units connected by conjugated imine bonds were transformed into conjugation-broken amine-linked COFs through linkage reduction,allowing for precise modulation of their electrochemical and electrochromic properties.The electrochemical oxidation onset potential of the amine-linked COF film was significantly reduced by approximately 0.6 V,and their absorption in the NIR region exhibits a marked enhancement and blue shift during electrochemical oxidation.Combining experimental and computational approaches,this phenomenon was attributed the previously unreported short-range charge interactions between triphenylamine and adjacent amine groups.The amine-linked COFs exhibit low electrochromic driving voltages(0.2 V),sub-second response times,high coloration efficiency,and stable electrochromic-switch properties.Notably,the low-voltage-driven amine-linked COFs showed pronounced NIR color changes with non-apparent visible color changes,leveraging this characteristic to achieve concealed information display in the NIR region.This work demonstrates the importance of linkage engineering in the design and preparation of high-quality optoelectronic functional COF materials and highlights the great application potential of optoelectronic COFs.
基金supported by the National Natural Science Foundation of China (21872154), Beijing National Science Foundation (2191003)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB12010400)
文摘A cyclometalated diruthenium complex 2 bridged by 1,2,4,5-tetra(pyrid-2-yl)benzene with six carboxylic acid groups at two ends was synthesized.Monolayer and multilayer films FTO/TiO2/(2)n(Zr)(n=1,2)and FTO/SnO2:Sb/(2)n(Zr)(n=1-4)have been prepared via interfacial layer-by-layer coordination assembly of 2 with zirconium(IV)ions.All films show two consecutive redox couples in the potential range between 0 and+1.0 V vs.Ag/AgCl.These films exhibit reversible near-infrared electrochromism upon switching of redox potential.The response time of the films on SnO2:Sb is around a few seconds,while that on TiO2 is around a few tens of seconds.The film deposition cycles were found to have a great impact on the electrochromic performance.Among six films examined,the two-layered film on SnO2:Sb displays the best balanced performance with a contrast ratio of 56%at 1,150 nm and good cyclic stability(9%loss of contrast ratio after 1,000 continuous double-potential-switching cycles),which is superior to that of the previously reported electropolymerized films of a related diruthenium complex with the same bridging ligand.In addition,the X-ray photoelectron spectroscopy,scanning electron microscopy,and electron transfer mechanism of these films have been investigated.
基金research was made possible as a result of generous grants from the National Key Research and Development Program of China(grant no.2021YFB3200700)the Natural Science Foundation of China(grant nos.22175138,21875180,and 52203240)+4 种基金the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University(grant no.PY3A066)the China National Postdoctoral Program for Innovative Talents(grant no.BX2021231)the Fundamental Research Funds for the Central Universities(grant no.sxjh032021099)the China Postdoctoral Science Foundation(grant no.2021M692545)the Natural Science Foundation of Shaanxi Province(grant no.2021JQ-043).
文摘Flexible electronics play a key role in the development of human society and our daily activities.Currently they are expected to revolutionize personal health management.However,it remains challenging to fabricate smart sensors with high robustness,reliability,and visible readout.Herein,high-performance electrochromic(EC),electro-fluorochromic(EFC),and double-network ionogels with excellent transmissivity,high mechanical robustness,and ultrastable reversibility are prepared by combination of thienoviologen-containing ionic liquids with poly(ethyl acrylate)elastomer.The ionogels exhibit good mechanical properties(1000%stretchability and 3.2 kJ m^(−2) fracture energy).The ionogel-based EC devices have a significantly simplified device fabrication process as well as superior cycling stability in which 88%of the contract ratio is maintained at 88%at 500 cycles,even after being stored for 2 years under ambient atmosphere(relative humidity:30%∼40%,25°C).The conductivity of ionogels showed a fast and reproducible response to strain,and the conductivity decreased with increased strain.By virtue of the EC and EFC properties of the thienoviologen component,the EC and EFC efficiency decreased with the increased strain loaded on the ionogels,and almost no EC or EFC phenomena were observed when the strain was above 300%.This feasible strategy provides an opportunity for the development of visible strain sensors to monitor the body’s movements through color and fluorescence emission.
基金This research was suported by the National Natural Science Foundation of China(Grant Nos.51521002,21905098)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(Grant No.20198121205002).
文摘Doping plays an essential role in the properties of conducting polymers.Film thickness not only has a direct influence on their photoelectric properties,but also affects the doping ability,which may lead to the decline of capacitance and electrochromic properties caused by incomplete doping.Therefore,it is essential to study the quantitative relationship between doping level and film thickness in application.Herein,empirical formula between doping level and thickness was obtained by studying the spectroelectrochemistry behaviors of two different electrochromic materials,poly(N,N'-bis(3,5-(2-thienyl)-phenyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-perylenetetracarboxylic diimide)(poly(Th-Cl-PBI))and poly(3,4-ethylenedioxythiophene)(PEDOT).The doping level is verified to be correlated to the reciprocal of the 3^(rd)power of film thickness.Experimental results fit these formulas very well,giving correlation coefficient R^(2)higher than 0.99.The optical contrast prediction of these two electrochromic materials is also used to verify this relationship formula.For the first time,we quantitatively connect these two important parameters of conducting polymers,doping level and thickness.
基金Supported by the National Natural Science Foundation of China(No.52103232)the Natural Science Foundation of Zhejiang Province,China(Nos.LY24E030012,LY19E030006)。
文摘Cyclopentadithiophene(CPDT)-based polymers have emerged as promising research platforms for multi⁃color electrochromic materials due to their favorable color tunability.However,insufficient cyclic stability has hindered their translation into practical applications.In this study,two CPDT-based conjugated polymers with distinct substituent groups were designed and synthesized:PCPDT-Ph(copolymerized with unsubstituted benzene units)and PCPDT-PhOMe(copolymerized with dimethoxy-substituted benzene units).The influence of dimethoxy substitution on the electrochromic properties and stability of the polymers was systematically investigated.Electro⁃chemical and electrochromic characterizations demonstrated that the electron-donating ability of the dimethoxy groups not only effectively regulated the polymer’s intrinsic properties but also significantly enhanced its cycling stability.Compared with PCPDT-Ph,PCPDT-PhOMe exhibited a reduced onset oxidation potential from 0.66 V(vs.Ag/AgCl)to 0.46 V,an upshifted highest occupied molecular orbital(HOMO)energy level,and a narrowed optical band gap(calculated theoretically)from 1.73 eV to 1.61 eV.The PCPDT-PhOMe film showed magenta in the neutral state and transparency in the oxidized state,with a color difference(ΔE*a b)of 46.36.The coloring/bleaching response times were measured as 0.7/0.6 s,and the optical contrast retention reached 84%after 1000 cycles,outperforming the PCPDT-Ph film(79.5%retention after 500 cycles).Additionally,it exhibited a coloration efficiency of 543.9 cm^(2)/C,demonstrating favorable comprehensive electrochromic performance.Electrochromic devices assembled with PCPDT-PhOMe achieved reversible switching between magenta and transparent states,with a response time of≤1.0 s and a contrast retention of 71%after 30000 cycles,indicating good stability.This work clarifies the role of substituent electronic effects in regulating the electrochromic properties of CPDT-based polymers,providing experimental basis and theoretical support for the molecular design of solution-processable thiophene-based electrochromic materials.Furthermore,it validates the potential application of PCPDT-PhOMe in smart windows,electronic displays,and other related fields.
基金Funded by the Natural Science Foundation of Guangdong(Nos.2014A030313241,2014B090901068,and 2016A010103003)。
文摘Two viologen derivatives containing fluorine substituent(F)with an asymmetric structures,1,1'-bis(4-(trifluoromethyl)phenyl)-[4,4'-bipyridine]dihexafluorophosphate(DFPV)and 1-benzyl-1'-(4-(trifluoromethyl)phenyl)-[4,4'-bipyridine]di-hexafluorophosphate(Bn-FPV),were synthesized.These viologen derivatives as active materials were used to assemble both flexible and rigid electrochromic devices(ECDs).ECDs based on DFPV exhibited reversible color change from colorless to deep green and ECDs based on Bn-FPV exhibited reversible color change from colorless to blue-green within applied voltage.It was found that the devices based on DFPV showed cycle stability,which could still maintain more than 90% after 1000 cycles.In addition,the modulation rate of the device to the solar irradiance is also calculated to characterize its application potential in smart windows.Among them,the rigid device(R-DFPV)based on the DFPV has a large solar irradiance modulation rate of 54.66%,which has the potential to be used as smart windows.
基金supported by the National Natural Science Foundation of China(52103299)。
文摘With the global push for energy conservation and the rapid development of low-power,flexible and wearable optical displays,the demand for electrochromic technology has surged.Gel polymer electrolytes(GPEs),a crucial component of electrochromic devices(ECDs),show great promise in applications.This is attributed to their efficient ion-transport capabilities,excellent mechanical properties and strong adhesion.All of these characteristics are conducive to enhancing the safety of the devices,streamlining the packaging process,significantly improving the electrochromic performance of ECDs and boosting their commercial application potential.This review provides a comprehensive overview of GPEs for ECDs,focusing on their basic designs,functional modifications and practical applications.Firstly,this review outlines the fundamental design of GPEs for ECDs,encompassing key performance index,classification,gelation mechanism and preparation methods.Building on this foundation,it provides an in-depth discussion of functionalized GPEs developed to enhance device performance or expand functionality,including electrochromic,temperature-responsive,photo-responsive and stretchable self-healing GPE.Furthermore,the integration of GPEs into various ECD applications,including smart windows,displays,energy storage devices and wearable electronic,are summarized to highlight the advantages that the design of GPEs brings to the practical application of ECDs.Finally,based on the summary of GPEs employed for ECDs,the challenges and development expectations in this direction were indicated.
文摘Curtain wall systems have evolved from aesthetic facade elements into multifunctional building envelopes that actively contribute to energy efficiency and climate responsiveness.This reviewpresents a comprehensive examination of curtain walls from an energy-engineering perspective,highlighting their structural typologies(Stick and Unitized),material configurations,and integration with smart technologies such as electrochromic glazing,parametric design algorithms,and Building Management Systems(BMS).Thestudy explores the thermal,acoustic,and solar performance of curtain walls across various climatic zones,supported by comparative analyses and iconic case studies including Apple Park,Burj Khalifa,and Milad Tower.Key challenges—including installation complexity,high maintenance costs,and climate sensitivity—are critically assessed alongside proposed solutions.A central innovation of this work lies in framing curtain walls not only as passive architectural elements but as dynamic interfaces that modulate energy flows,reduce HVAC loads,and enhance occupant comfort.The reviewed data indicate that optimized curtain wall configurations—especially those integrating electrochromic glazing and BIPV modules—can achieve annual energy consumption reductions ranging fromapproximately 5%to 27%,depending on climate,control strategy,and facade typology.The findings offer a valuable reference for architects,energy engineers,and decision-makers seeking to integrate high-performance facades into future-ready building designs.
基金the support from National Natural Sci-ence Foundation of China(52276178)Natural Science Foundation of Jiangsu Province,China(BK20200373).
文摘Building fresh air supply needs to meet certain regulations and fit people’s ever-growing indoor air quality de-mand.However,fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings.Thus,in this work,an adaptive fresh air pre-handling system is designed to reduce the cool-ing and heating loads of HVAC system.The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy(solar heating)and deep space cold source(radiative cooling)by switching between heating and cooling modes.In the cooling mode,the sky-facing surface shows a transmittance of down to zero,while the reflectance is high at 0.89 on average.In the heating mode,the electrochromic glass is highly transparent,allowing the sunlight to reach the solar heat absorber.To obtain the energy-saving potential under different climates,six cities were selected from various climate regions in China.Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4%time of a year.The maximum energy-saving ratios for medium office,warehouse,and single-family house can reach up to 11.52%,26.62%,and 18.29%,respectively.In addition,the system shows multi-climate adaptability and broad application scenarios,making it a potential solution to building energy saving.
基金Funds for the Central Universities(Nos.HIT.OCEF.2021004 and FRFCU5710090220).
文摘Prussian blue(PB)is an anodic coloring candidate in the wide area of electrochromic(EC)applications.However,the co-influence of weak adhesion and low electrical conductivity leads to the poor stability and slow switching speed.To tackle this bottleneck,a novel TiO_(2)/Au/PB nanorod array is designed through hydrothermal and electrodeposition approaches on fluorine-doped tin oxide(FTO)glass.Such a designed ternary array structure could not only increase reactive site and conductivity,but also improve ion storage capacity and promote charge transfer,attributed to the synergistic effect of TiO_(2)/Au/PB core–shell heterostructure and the localized surface plasmon resonance(LSPR)effect of Au nanoparticles.Besides,density functional theory(DFT)calculation confirms the strong interaction between rutile TiO_(2)and FTO substrate,which contributes to the improvement of EC cycle stability.Benefiting from these effects,the TiO_(2)/Au/PB film shows a fast coloration/bleaching response of 1.08/2.01 s(2.17/4.48 s,PB film)and ultra-stable EC performance of 86.8%after 20,000 cycles(50%after 600 cycles,PB film).Furthermore,the high-intensity light source can be shot clearly by the designed and assembled EC iris device(ECID)with TiO_(2)/Au/PB film as an EC layer,while the photograph without an ECID is blurry,confirming the feasibility of the material in portable digital products.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.22075168,21701105,21871167&91961201)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SX-FR003)。
文摘In our work,polymorphism strategy has been successfully applied to tune up chromism and luminescence properties of viologen-based materials.Two polymorphs of viologen-based complexes ofα-CdBr_(2)(PHSQ)_(2)(H_(2)O)_(2)(1)andβ-CdBr_(2)(PHSQ)_(2)(H_(2)O)_(2)(2)(PHSQ=N-(4-sulfophenyl)-4,4-bipyridinium)were synthesized by changing the solvent.They can both respond to UV light and electricity in the manner of chromism visible to the naked eye and the coloration states have good reversibility,through which an inkless erasable printing model has been established.But the coloration contrast of 1 is higher compared to 2.Meanwhile,they both exhibit photoluminescence properties and the intensity of 1 is twice that of 2,which is accompanied by photoquenching upon continuous UV light irradiation.The only divergence of disordered/ordered O atoms in the two crystalline compounds leads to significantly different chromic and luminescent properties.Further explorations simultaneously demonstrate that the different chromic performance between 1 and 2 should attribute to the alteration of stimulus-induced(light/electricity)electron transfer channels caused by the ordered/disordered O atoms in the complexes,which is achieved through C-H···O and O-H···O interactions to change crystal arrangement and structural rigidity,thus affect luminescent properties.
基金the National Natural Science Foundation of China(No.52272009)the Henan Provincial Science and Technology Research Project(No.242102230151)+1 种基金the Henan Provincial University Science and Technology Innovation Team(No.25IRTSTHN009)the Key Scientific Research Projects of Colleges and Universities in Henan Province(Nos.24B560021,25B560020,25B560023)。
文摘This paper adopted the hydrothermal method to prepare tungsten oxide(WO_(3))nanorod films and studied the effects of precursor solution concentration(0.02,0.03,0.06 mol/L peroxytungstic acid)and annealing temperature(200,300,400℃)on their electrochromic properties.The microstructure characterization of WO_(3) films were performed using scanning electron microscope(SEM),X-ray diffraction(XRD),and transmission electron microscope(TEM),and their electrochromic properties were tested by combining an electrochemical workstation with an ultraviolet-visible spectrophotometer.The results showed that the precursor solution concentration directly affected the thickness(290,560,990 nm)and microstructure of WO_(3) films,significantly impacting their electrochromic properties.However,the annealing temperature had a negligible effect.As the precursor solution concentration increased,the optical modulation of WO_(3) films gradually decreased,reaching 51.1%,43.8%,and 35.1%,respectively.The switching time first increased and then stabilized,with coloring times of 7.3,7.7,and 7.7 s,respectively,and bleaching times of 3.8,6.5,and 6.5 s,respectively.The coloration efficiency gradually increased but the increase was relatively small,reaching 41.8,44.4,and 44.8 cm^(2)/C,respectively.Moreover,the cycling stability of WO_(3) films was poor,with the ratios of the final value of optical modulation to the initial value 0.33,0.26,and 0.34,respectively.Additionally,there were bigger differences in the bleached state transmittance,while the colored state transmittance showed smaller variations.However,the former has better cycling stability than the latter.In summary,to obtain better electrochromic properties,the thickness of WO_(3) films should not exceed 290 nm.
