Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current st...Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current strategy for building DESWs is to screen materials for composite or prepare plasmonic nanocrystal films.These rigorous preparation processes seriously limit the further development of DESWs.Herein,we report a facile and effective sol-gel strategy using a foaming agent to achieve porous Ti-doped tungsten oxide film for the high performance of DESWs.The introduction of foaming agent polyvinylpyrrolidone during the film preparation can increase the specific surface area and free carrier concentration of the films and enhance their independent regulation ability of near-infrared electrochromism.As a result,the optimal film shows excellent dual-band electrochromic properties,including high optical modulation(84.9%at 633 nm and 90.3%at 1200 nm),high coloration efficiency(114.9 cm^(2) C^(-1) at 633 nm and 420.3 cm^(2) C^(-1) at 1200 nm),quick switching time,excellent bistability,and good cycle stability(the transmittance modulation losses at 633 and 1200 nm were 11%and 3.5%respectively after 1000 cycles).A demonstrated DESW fabricated by the sol-gel film showed effective management of heat and light of sunlight.This study represents a significant advance in the preparation of dual-band electrochromic films,which will shed new light on advancing electrochromic technology for future energy-saving smart buildings.展开更多
Electrochromic smart windows have attracted much attention in energy-saving buildings because of their ability to selectively modulate visible(VIS)and near-infrared(NIR)light transmittance.As is known,the NIR region a...Electrochromic smart windows have attracted much attention in energy-saving buildings because of their ability to selectively modulate visible(VIS)and near-infrared(NIR)light transmittance.As is known,the NIR region accounts for about 50%of the total solar radiation.Therefore,reducing the NIR transmittance of windows will play a crucial role in reducing the energy consumption of buildings.However,for most of the reported electrochromic materials(ECMs)-based windows,it remains a longlasting challenge about how to achieve a low NIR transmittance during the past decades.In this work,we synthesize oxygendeficient tungsten oxide(WO_(3−x))nanoflowers(NFs)by a simple and efficient method that is facile for their mass production.The WO_(3−x)NFs exhibit low NIR transmittance of only 4.11%,0.60%,and 0.19%at 1200,1600,and 1800 nm,respectively,due to the localized surface plasmon resonance(LSPR)effect.Besides,the WO_(3−x)NFs exhibit an excellent dual-band modulating ability for both VIS and NIR light.They are able to operate in three distinct modes,including a bright mode,a cool mode,and a dark mode.Moreover,the WO_(3−x)NFs exhibit a fast bleaching/coloring time(1.54/6.67 s),and excellent cycling stability(97.75%of capacity retention after 4000 s).展开更多
With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields o...With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields of smart windows,electronic billboards,emerging wearable and portable electronics,and other next-generation displays.Nickel oxide(NiO)is a promising candidate for high-performance ECMs because of its neutral-colored states and low cost.However,NiO-based ECMs still face the problem of slow switching speed due to their low electrical conductivity and small lattice spacing.Metal-organic frameworks(MOFs)are promising candidates to fabricate hollow and porous transition metal oxides(TMOs)with high ion transport efficiency,excellent specific capacitance,and electrochemical activities.In this work,porous yolk-shell NiO nanospheres(PYS-NiO NSs)were syn-thesized via a solvothermal and subsequent calcination process of Ni-MOF,which exhibited outstanding EC performance.Because the large specific surface areas and hollow porous nanostructures were conducive to ionic transport,PYS-NiO NSs exhibited a fast coloring/bleaching speed(3.6/3.9 s per one coloring/bleaching cycle)and excellent cycling stability(82%of capacity retention after 3000 cycles).These superior EC properties indicated that the PYS-NiO NSs was a promising candidate for high-performance EC devices.This work provides a new and feasible strategy for the efficient preparation of TMOs ECMs with good EC performance,especially fast switching speed.展开更多
Based on the previous studies on the rf reactive sputtered nickel oxide film with nanostructure and its electrochromism, i. e. electrochromic effect of the films is attributed to the reversible change of the non-stoic...Based on the previous studies on the rf reactive sputtered nickel oxide film with nanostructure and its electrochromism, i. e. electrochromic effect of the films is attributed to the reversible change of the non-stoichiometry in the nanocrystaltine gram boundaries and interfaces due to the injection and ejection of Li+ ions, a prototype of all-solid-state NiO/WO3 complementary electrochromic device using LixTaOy thin film as inorganic electrolyte was designed and prepared. The results indicate that the solar reflectance of the device could be modulated from 0. 15 in colored state to 0.60 in bleached state with excellent cyclic reversibility, durability and high response speed (less than 0.3 s from colored state to bleached state).展开更多
基金supported by the National Natural Science Foundation of China(51902064)the Natural Science Foundation of Guangxi(2022GXNSFFA0350325)+2 种基金the Scientific and Technological Bases and Talents of Guangxi(Guike AD20159073)the special fund for“Guangxi Bagui Scholars”the“Guangxi HundredTalent Program”。
文摘Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current strategy for building DESWs is to screen materials for composite or prepare plasmonic nanocrystal films.These rigorous preparation processes seriously limit the further development of DESWs.Herein,we report a facile and effective sol-gel strategy using a foaming agent to achieve porous Ti-doped tungsten oxide film for the high performance of DESWs.The introduction of foaming agent polyvinylpyrrolidone during the film preparation can increase the specific surface area and free carrier concentration of the films and enhance their independent regulation ability of near-infrared electrochromism.As a result,the optimal film shows excellent dual-band electrochromic properties,including high optical modulation(84.9%at 633 nm and 90.3%at 1200 nm),high coloration efficiency(114.9 cm^(2) C^(-1) at 633 nm and 420.3 cm^(2) C^(-1) at 1200 nm),quick switching time,excellent bistability,and good cycle stability(the transmittance modulation losses at 633 and 1200 nm were 11%and 3.5%respectively after 1000 cycles).A demonstrated DESW fabricated by the sol-gel film showed effective management of heat and light of sunlight.This study represents a significant advance in the preparation of dual-band electrochromic films,which will shed new light on advancing electrochromic technology for future energy-saving smart buildings.
基金the Tsinghua-Toyota Joint Research Fund,the National Key Research Program(Nos.2020YFA0210702 and 2020YFC2201103)the National Natural Science Foundation of China(Nos.51872156 and 22075163)the China Postdoctoral Science Foundation funded project(No.2022M721808).
文摘Electrochromic smart windows have attracted much attention in energy-saving buildings because of their ability to selectively modulate visible(VIS)and near-infrared(NIR)light transmittance.As is known,the NIR region accounts for about 50%of the total solar radiation.Therefore,reducing the NIR transmittance of windows will play a crucial role in reducing the energy consumption of buildings.However,for most of the reported electrochromic materials(ECMs)-based windows,it remains a longlasting challenge about how to achieve a low NIR transmittance during the past decades.In this work,we synthesize oxygendeficient tungsten oxide(WO_(3−x))nanoflowers(NFs)by a simple and efficient method that is facile for their mass production.The WO_(3−x)NFs exhibit low NIR transmittance of only 4.11%,0.60%,and 0.19%at 1200,1600,and 1800 nm,respectively,due to the localized surface plasmon resonance(LSPR)effect.Besides,the WO_(3−x)NFs exhibit an excellent dual-band modulating ability for both VIS and NIR light.They are able to operate in three distinct modes,including a bright mode,a cool mode,and a dark mode.Moreover,the WO_(3−x)NFs exhibit a fast bleaching/coloring time(1.54/6.67 s),and excellent cycling stability(97.75%of capacity retention after 4000 s).
基金supported by the Tsinghua-Toyota Joint Research Fund,National Key Research Program(grant Nos.2020YFA0210702 and 2020YFC2201103)the National Natural Science Foundation of China(grant Nos.51872156 and 22075163)China Postdoctoral Science Foundation funded project(grant No.2022M721808).
文摘With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields of smart windows,electronic billboards,emerging wearable and portable electronics,and other next-generation displays.Nickel oxide(NiO)is a promising candidate for high-performance ECMs because of its neutral-colored states and low cost.However,NiO-based ECMs still face the problem of slow switching speed due to their low electrical conductivity and small lattice spacing.Metal-organic frameworks(MOFs)are promising candidates to fabricate hollow and porous transition metal oxides(TMOs)with high ion transport efficiency,excellent specific capacitance,and electrochemical activities.In this work,porous yolk-shell NiO nanospheres(PYS-NiO NSs)were syn-thesized via a solvothermal and subsequent calcination process of Ni-MOF,which exhibited outstanding EC performance.Because the large specific surface areas and hollow porous nanostructures were conducive to ionic transport,PYS-NiO NSs exhibited a fast coloring/bleaching speed(3.6/3.9 s per one coloring/bleaching cycle)and excellent cycling stability(82%of capacity retention after 3000 cycles).These superior EC properties indicated that the PYS-NiO NSs was a promising candidate for high-performance EC devices.This work provides a new and feasible strategy for the efficient preparation of TMOs ECMs with good EC performance,especially fast switching speed.
基金Project supported by the National Natural Science Foundation of China and the National Climbing Programme A: Nanostructured Materials Sciences.
文摘Based on the previous studies on the rf reactive sputtered nickel oxide film with nanostructure and its electrochromism, i. e. electrochromic effect of the films is attributed to the reversible change of the non-stoichiometry in the nanocrystaltine gram boundaries and interfaces due to the injection and ejection of Li+ ions, a prototype of all-solid-state NiO/WO3 complementary electrochromic device using LixTaOy thin film as inorganic electrolyte was designed and prepared. The results indicate that the solar reflectance of the device could be modulated from 0. 15 in colored state to 0.60 in bleached state with excellent cyclic reversibility, durability and high response speed (less than 0.3 s from colored state to bleached state).
