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
Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nano...Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nanosheets via a hot injection method.In this method,NdF_(3) nanosheets with only about 2 nm in thickness synthesized first via a hot injection method.The shape of the NdF_(3) nanosheets was able to be tailored from flower-like to the round or the triangular shapes simply by decreasing the reaction temperature from 300℃to 280℃or 260℃.The driven force of the NdF_(3) nanosheets’shape tailoring by the temperature could be that a lower crystal growth rate will guarantee the more stable facets exposed at lower temperature,while under the condition of slow precursor injection,a higher temperature will lead to a further decrease in the crystal growth rate.This shape control method of NdF_(3) nanosheets is highly robust,which could be promoted to other materials.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.
文摘Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nanosheets via a hot injection method.In this method,NdF_(3) nanosheets with only about 2 nm in thickness synthesized first via a hot injection method.The shape of the NdF_(3) nanosheets was able to be tailored from flower-like to the round or the triangular shapes simply by decreasing the reaction temperature from 300℃to 280℃or 260℃.The driven force of the NdF_(3) nanosheets’shape tailoring by the temperature could be that a lower crystal growth rate will guarantee the more stable facets exposed at lower temperature,while under the condition of slow precursor injection,a higher temperature will lead to a further decrease in the crystal growth rate.This shape control method of NdF_(3) nanosheets is highly robust,which could be promoted to other materials.
