共查询到20条相似文献,搜索用时 15 毫秒
1.
The authors present high-color-rendering-index (CRI) white polymer light-emitting electrochemical cells (PLECs) based on ionic host-guest systems. PLECs were fabricated with blend films composed of a blue fluorescent cationic π-conjugated polymer, poly(9,9-bis[6′-(N,N,N,-trimethylammonium)hexyl]fluorine-co-alt-1,4-phenylene)bromide (PFN+Br−), used as a host, and a red phosphorescent cationic iridium complex, [Ir(ppy)2(biq)]+(PF6)− (where (ppy)− = 2-phenylpyridinate and biq = 2,2′-biquinoline), used as a guest. By optimizing the composition of PFN+Br− and [Ir(ppy)2(biq)]+(PF6)− in the active layers, white light emission with Commission Internationale de l'Eclairage (CIE) coordinates of (x = 0.28, y = 0.31) and a very high CRI of 95.8 was achieved through mixing of blue and red light at an applied voltage of 4.0 V. The white light emissions were obtained at a low [Ir(ppy)2(biq)]+(PF6)− concentration (PFN+Br−:[Ir(ppy)2(biq)]+(PF6)− = 1:0.01 (mass ratio)), showing that [Ir(ppy)2(biq)]+(PF6)− acts as a suitable energy acceptor. The emission mechanism of the ionic host-guest PLECs can be explained by Förster resonance energy transfer (FRET) and Dexter energy transfer (DET) from the excited PFN+Br− to [Ir(ppy)2(biq)]+(PF6)−. Utilization of ionic host-guest PLECs is a very promising method for realizing white light-emitting devices with very high CRI. 相似文献
2.
Xiaohui Lin Long Chen Chenglin He Yiliu Wang Xu Li Weiqi Dang Kun He Ying Huangfu Dan Wu Bei Zhao Bo Li Jia Li Xidong Duan 《Advanced functional materials》2023,33(1):2210278
Single crystal metal halide perovskites thin films are considered to be a promising optical, optoelectronic materials with extraordinary performance due to their low defect densities. However, it is still difficult to achieve large-scale perovskite single-crystal thin films (SCTFs) with tunable bandgap by vapor-phase deposition method. Herein, the synthesis of CsPbCl3(1–x)Br3x SCTFs with centimeter size (1 cm × 1 cm) via vapor-phase deposition is reported. The Br composition of CsPbCl3(1–x)Br3x SCTFs can be gradually tuned from x = 0 to x = 1, leading the corresponding bandgap to change from 2.29 to 2.91 eV. Additionally, an low-threshold (≈23.9 µJ cm−2) amplified spontaneous emission is achieved based on CsPbCl3(1–x)Br3x SCTFs at room temperature, and the wavelength is tuned from 432 to 547 nm by varying the Cl/Br ratio. Importantly, the high-quality CsPbCl3(1–x)Br3x SCTFs are ideal optical gain medium with high gain up to 1369.8 ± 101.2 cm−1. This study not only provides a versatile method to fabricate high quality CsPbCl3(1–x)Br3x SCTFs with different Cl/Br ratio, but also paves the way for further research of color-tunable perovskite lasing. 相似文献
3.
Wenjing Lu Pengcheng Xu Siyuan Shao Tianyu Li Huamin Zhang Xianfeng Li 《Advanced functional materials》2021,31(30):2102913
Zinc-bromine flow batteries (ZBFBs) are regarded as one of the most promising technologies for energy storage owing to high energy density and low cost. However, the sluggish reaction kinetics of Br2/Br− couples and zinc dendrite issue lead to low power density and poor cycle stability. Herein, a multifunctional carbon felt-based electrode (NTCF) with N-rich defects is fabricated for ZBFBs. The defects with abundant N-containing groups on carbon fibers of NTCF provide high catalytic activity on Br2/Br− reactions. Simultaneously, the lower energy barrier of N-rich defects to adsorb zinc atoms, and more deposition sites on NTCF induce more uniform zinc deposition. Thus, a ZBFB using NTCF as both the anode and cathode can stably operate at an unprecedentedly high current density of 180 mA cm−2 with a coulombic efficiency of 97.25%. Moreover, a long cycle life of over 140 cycles with a coulombic efficiency of 98.93% for a Zn symmetric flow battery at 80 mA cm−2 is achieved under a high areal capacity of 40 mAh cm−2. This current density and areal capacity are by far the highest values ever reported for Zn symmetry flow batteries. Therefore, this work provides an available approach to improve the power density and cycle life of ZBFBs. 相似文献
4.
Chuanfang Yan Yuting Wan Hongping Long Huang Luo Xuan Liu Hang Luo Sheng Chen 《Advanced functional materials》2024,34(8):2312238
In this work, p-type polymer semiconductor poly(2-((3,6,7,10,11-pentakis (hexyloxy) triphenylene-2-yl)oxy)ethyl methacrylate) (PMHT) is added into polyetherimide (PEI). Benefiting from the electrostatic interaction between strong electrophilic charged phenyls of the PEI matrix and strong electronegative benzophenanthrene unit of the PMHT filler, the physical cross-linked networks are formed in polymer blends. Meanwhile, the lowest unoccupied molecular orbital level of PEI is close to the highest occupied molecular orbital level of PMHT, which is easy to establish electron–hole pair by Coulomb force. Thus, the carrier trap is constructed in the heterojunction region between PMHT filler and PEI matrix. Both physically cross-linked networks and electron–hole pairs can promote breakdown strength (Eb) of PEI and decrease energy loss. Importantly, PMHT filler can improve the dielectric constant of PEI. As a result, 0.75 wt% PMHT/PEI delivers an ultrahigh discharge energy density (Ud) of 10.7 J cm−3 at an Eb of 680 MV m−1 and at room temperature, and maintains a charge and discharge efficiency of above 90%. In addition, a superior Ud of 5.1 and 3.3 J cm−3 is achieved at 150 and 200 °C, respectively. This paper creates a new perspective for preparing high-properties polymer dielectrics by combining the advantages of cross-linking and electron–hole pairs. 相似文献
5.
Jie Xiao Muyu Cong Minmin Li Xin Zhang Yahui Zhang Xinjia Zhao Wenqi Lu Zhimou Guo Xinmiao Liang Guangyan Qing 《Advanced functional materials》2024,34(2):2307996
Osmotic energy represents a promising energy resource because it is sustainable and environmentally benign. Subnanoscale channels are considered as a competitive platform for generating this blue energy due to their highly selective and ultrafast ion transport. However, fabricating functional subnanochannels capable of high energy output remains challenging. Here, a heterogeneous subnanochannel membrane formed by coating a functionalized self-assembled metal−organic framework (MOF) monolayer (SAMM) film on a porous anodic aluminum oxide membrane, is reported. The SAMM film, with a thickness of ≈160 nm, is fabricated by self-assembly of poly(methyl methacrylate-co-vinylimidazole)-modified UiO-66-NH2 nanoparticles at the water−air interface. In the SAMM, imidazole and NH2 groups provide abundant positive charges, while the angstrom-scale windows act as ionic filters for selective screening of anions with different hydration diameters. As a result, the heterogeneous membrane exhibits excellent capacity for anion-selective transport, which contributes to an optimal osmotic power of 6.76 W m−2 under a 100-fold NaCl gradient, as well as a high Cl−/SO42− selectivity of ≈42.2. Further, the output power is increased to 10.5 W m−2 by methylating imidazole moieties on the MOF surface. This work provides a facile and modular approach to fabricate subnanochannels for enabling highly selective and efficient osmotic energy conversion. 相似文献
6.
Kun Zhang Xing Li Yong Yang Zhongxin Chen Li Ma Yaohua Zhao Yijia Yuan Fangzheng Chen Xiaowei Wang Keyu Xie Kian Ping Loh 《Advanced functional materials》2023,33(11):2212759
Simultaneously attaining high gravimetric energy density (Eg) and volumetric energy density (Ev) in lithium-sulfur (Li–S) batteries is a longstanding challenge that has to be solved for practical application, which demands breakthroughs in electrode materials with optimized functionality and structure. Herein, anthraquinone-containing, reactive-type polymer tubes (PQT) that can be used to regulate the redox chemistry of sulfur species are designed and prepared for practical Li–S batteries. PQT favors a similar redox potential window as sulfur, which effectively facilitates the immobilization and conversion of sulfur species through a reversible lithiation/delithiation process. Its tubular structure and high tap density is vital to the fabrication of intact electrode with high sulfur loading and minimizing electrolyte intake during battery operation. With all these contributions, Li–S battery with PQT/S cathode exhibits a stable cycling capacity (73% at 2.0 C over 1000 cycles), remarkable rate performance (514.2 mAh g−1 at 10 C), and a high areal capacity of 7.20 mAh g−1 with high sulfur loading under lean electrolyte condition. More importantly, the assembled Li–S pouch cell delivers an Eg of 329 Wh kg−1 and an Ev of 401 Wh L−1, which meets the requirement for practical operation. 相似文献
7.
Chang-Feng Wang Haojin Li Mao-Guang Li Yu Cui Xin Song Qin-Wen Wang Jia-Ying Jiang Miao-Miao Hua Qi Xu Kui Zhao Heng-Yun Ye Yi Zhang 《Advanced functional materials》2021,31(13):2009457
Ferroelectricity and X-ray detection property have been recently implemented for the first time in hybrid bromide double perovskites. It sheds a light on achieving photosensitive and ferroelectric multifunctional materials based on 2D lead-free hybrid halide double perovskites. However, the low Tc, small Ps, and relatively low X-ray sensitivity in the reported bromide double perovskites hinder practical applications. Herein, the authors demonstrate a novel 2D lead-free iodide double perovskite (4,4-difluoropiperidinium)4AgBiI8 (1) for high-performance X-ray sensitive ferroelectric devices. Centimeter-sized single crystal of 1 is obtained and exhibits an excellent ferroelectricity including a high Tc up to 422 K and a large Ps of 10.5 μC cm−2. Moreover, due to a large X-ray attenuation and efficient charge carrier mobility (μ)–charge carrier lifetime (τ) product, the crystal 1 also exhibits promising X-ray response with a high sensitivity up to 188 μC·Gyair−1 cm−2 and a detection limit below 3.13 μGyair·s−1. Therefore, this finding is a step further toward practical applications of lead-free halide perovskite in high-performance photoelectronic devices. It will afford a promising platform for exploring novel photosensitive ferroelectric multifunctional materials based on lead-free double perovskites. 相似文献
8.
Jiaqi Ke Zhipeng Wen Yang Yang Rong Tang Yongchao Tang Minghui Ye Xiaoqing Liu Yufei Zhang Cheng Chao Li 《Advanced functional materials》2023,33(26):2301129
Artificial interface layer engineering is an efficacious modification strategy for protecting zinc anode from dendrite growth and byproducts formation. However, the high bulk ionic conductivity of most artificial interfacial layers is mainly contributed by the movement of anions (SO42−), which is the source of parasitic reactions on zinc anode. Herein, a high zinc ion donor transition (σZn2+ = 3.89 × 10−2 S cm−1) imidazole polymeric ionic liquid interface layer (1-carboxymethyl-3-vinylimidazolium bromide monomer, CVBr) for Zn metal protection is designed. The N+ atom of imidazole rings is connected by chains to form the cavities and the anions are confined within these cavities. Thus, the hindering effect of surrounding units on the anions leads to the subdiffusive regime, which inhibits the diffusion of SO42− in interface and increases Zn2+ transference number. Besides, the polycation-anion coordination mechanism of PolyCVBr ensures accelerated Zn2+ transition and realizes rapid internal Zn2+ migration channel. As a result, the Zn@CVBr||AM symmetry cells deliver high bulk ionic conductivity (4.42 × 10−2 S cm−1) and high Zn2+ transference number (tZn2+ = 0.88) simultaneously. The Zn@CVBr||AM-NaV3O8 pouch cells display the capacity retention of 88.9% after 190 cycles under 90° bending, verifying their potential practical application. 相似文献
9.
Xiaoqi Li Zengshan Yue Fen Zhang Qianxi Wang Qingyin Wei Zhihua Sun Junhua Luo Xitao Liu 《Advanced functional materials》2024,34(12):2311944
Antiferroelectrics, characterized by electrically controlled antipolar-polar phase transformation, have attracted tremendous attention as a class of promising electroactive materials for assembling electronic devices. The emerging two-dimensional (2D) halide perovskites with superior compositional diversity offer an ideal platform for exploring electroactive materials, whereas lead-free antiferroelectric counterparts are still scarcely reported. Herein, for the first time, a new lead-free 2D germanium iodide perovskite antiferroelectric (i-BA)2CsGe2I7 ( 1 , i-BA is iso-butylammonium) has been presented, which exhibits a high Curie temperature (Tc) up to 403 K. Remarkably, benefiting from the lone pair stereochemical activity in Ge2+ induced large structural distortion and Cs+ ion off-center displacement, 1 shows well-defined double P–E hysteresis loops in a wide temperature range with a giant maximum polarization up to 18.8 µC cm−2, which achieves a new high record among molecular antiferroelectrics. Moreover, under a low external electric field of 22.5 kV cm−1, the antipolar-polar phase transformation in 1 affords a recoverable energy storage density Wrec of 0.27 J cm−3 and high storage efficiency up to 79.76%. Such lead-free halide perovskite antiferroelectric with intriguing antiferroelectric behaviors, including high Tc, large polarization and remarkable energy storage properties, is exciting, which provides an alternative candidate for high-performance antiferroelectrics for environmentally friendly electronic devices. 相似文献
10.
Alternating Magnetic Field-Enhanced Triboelectric Nanogenerator for Low-Speed Flow Energy Harvesting
Baosen Zhang Qi Gao Wenbo Li Mingkang Zhu Hengyu Li Tinghai Cheng Zhong Lin Wang 《Advanced functional materials》2023,33(42):2304839
Low-speed flow energy, such as breezes and rivers, which are abundant in smart agriculture and smart cities, faces significant challenges in efficient harvesting as an untapped sustainable energy source. This study proposes an alternating magnetic field-enhanced triboelectric nanogenerator (AMF-TENG) for low-speed flow energy harvesting, and demonstrates its feasibility through experimental results. AMF-TENG's minimum cut-in speed is 1 m s−1, thereby greatly expanding its wind energy harvesting range. When the wind speed is 1–5 m s−1, the open-circuit voltage (VOC) is 20.9–179.3 V. The peak power is 0.68 mW at 5 m s−1. In a durability test of 100 K cycles, the VOC decreases from 188.4 to 174.2 V but remain at 92.5% of the initial value. furthermore, the AMF-TENG can harvest low-speed flow energy from the natural environment to power temperature and humidity sensors and wireless light intensity sensor in smart agriculture. This study provides a promising method for low-speed flow energy harvesting in distributed applications. 相似文献
11.
Tianjiang Sun Haihui Du Shibing Zheng Jinqiang Shi Zhanliang Tao 《Advanced functional materials》2021,31(16):2010127
Freezing electrolyte and sluggish ionic migration kinetics limited the low-temperature performance of rechargeable batteries. Here, an aqueous proton battery is developed, which achieves both high power density and energy density at the ultralow temperature conditions. Electrolyte including 2 m HBF4 + 2 m Mn(BF4)2 is used for the ultralow freezing point of below − 160 ° C and high ionic conductivity of 0.21 mS cm−1 at − 70 ° C. Spectroscopic and nuclear magnetic resonance analysis demonstrate the introduction of BF4− anions efficiently break the hydrogen-bond networks of original water molecules, resulting in ultralow freezing point. Based on H+ uptake/removal reaction in alloxazine (ALO) anode and MnO2/Mn2+ conversion in carbon felt cathode, the aqueous proton battery can operate regularly even at − 90 ° C and obtain a high specific discharge capacity of 85 mA h g−1. Benefiting from the rapid diffusion of proton and the pseudocapacitive character of ALO electrolyte, this battery shows a high specific energy density of 110 Wh kg−1 at a specific power density of 1650 W kg−1 at − 60 ° C. This work presents a new way of developing low-temperature batteries. 相似文献
12.
《Optical Fiber Technology》2014,20(4):422-427
The ubiquity and importance of anions in many crucial roles accounts for the current high interest in the design and preparation of effective sensors for these species. Therefore, a tilted fiber Bragg grating sensor was fabricated to investigate individual detection of different anion concentrations in ethyl acetate, namely acetate, fluoride and chloride. The influence of the refractive index on the transmission spectrum of a tilted fiber Bragg grating was determined by developing a new demodulation method. This is based on the calculation of the standard deviation between the cladding modes of the transmission spectrum and its smoothing function. The standard deviation method was used to monitor concentrations of different anions. The sensor resolution obtained for the anion acetate, fluoride and chloride is 79 × 10−5 mol/dm3, 119 × 10−5 mol/dm3 and 78 × 10−5 mol/dm3, respectively, within the concentration range of (39–396) × 10−5 mol/dm3. 相似文献
13.
Junjie Li Hong-Hui Wu Jianting Li Xiaopo Su Ruowei Yin Shiqiang Qin Dong Guo Yanjing Su Lijie Qiao Turab Lookman Yang Bai 《Advanced functional materials》2021,31(33):2101176
As an emerging solid-state refrigeration technology with zero-emission and high energy conversion efficiency, there is a compelling need for ferroelectric materials with giant electrocaloric effects (ECEs) at room temperature suitable for refrigeration applications. The complex perovskite antiferroelectric (AFE), PbMg0.5W0.5O3, containing non-equivalent B-site ions with a symmetric giant positive and negative ECE near room temperature is presented. At the Curie temperature of 36 °C, the first-order AFE–paraelectric phase transition gives rise to a large enthalpy change of 3.92 J g−1, more than four times that of BaTiO3. This leads to a significant ECE under the influence of an electric field. The direct electrocaloric characterization shows that the adiabatic temperature change, ΔT, exhibits symmetric peaks with a giant positive maximum of 1.79 K (ΔS = 1.68 J kg−1 K−1) at 36 °C and a negative maximum of −2.02 K (ΔS = −1.93 J kg−1 K−1) at 34 °C. The ultrahigh magnitude of ΔT near room temperature makes PbMg0.5W0.5O3 a superior electrocaloric material far beyond traditional PbZrO3-based AFEs. The coexistence of symmetric giant positive and negative ΔT to further improve cooling efficiency is expected. In addition, the good reversibility and negligible leakage current should pave the way for practical applications. 相似文献
14.
Zhenping Wang Nasir Ali Tien Dat Ngo Hoseong Shin Sungwon Lee Won Jong Yoo 《Advanced functional materials》2023,33(28):2301651
Even though atomically thin 2D semiconductors have shown great potential for next-generation electronics, the low carrier mobility caused by poor metal–semiconductor contacts and the inherently high density of impurity scatterings remains a critical issue. Herein, high-mobility field-effect transistors (FETs) by introducing few-layer PdSe2 flakes as channels is achieved, via directly depositing semimetal antimony (Sb) as drain–source electrodes. The formation of clean and defect-free van der Waals (vdW) stackings at the Sb–PdSe2 heterointerfaces boosts the room temperature transport characteristics, including low contact resistance down to 0.55 kΩ µm, high on-current density reaching 96 µA µm−1, and high electron mobility of 383 cm2 V−1 s−1. Furthermore, metal–insulator transition (MIT) is observed in the PdSe2 FETs with and without hexagonal boron nitride (h–BN) as buffer layers. However, the layered h–BN/PdSe2 vdW stacking eliminates the interference of interfacial disorders, and thus the corresponding device exhibits a lower MIT crossing point, larger mobility exponent of γ ∼ 1.73, significantly decreased hopping parameter of T0, and ultrahigh electron mobility of 2,184 cm2 V−1 s−1 at 10 K. These findings are expected to be significant for developing high mobility 2D-based quantum devices. 相似文献
15.
Zheng Ma Tian Xu Wang Li Yiming Cheng Jinmeng Li Dan Zhang Qinghui Jiang Yubo Luo Junyou Yang 《Advanced functional materials》2021,31(30):2103197
A new p-type high entropy semiconductor AgMnGeSbTe4 with a band gap of ≈0.28 eV is reported as a promising thermoelectric material. AgMnGeSbTe4 crystallizes in the rock-salt NaCl structure with cations Ag, Mn, Ge, and Sb randomly disordered over the Na site. Thus, a strong lattice distortion forms from the large difference in the atomic radii of Ag, Mn, Ge, and Sb, resulting in a low lattice thermal conductivity of 0.54 W m−1 K−1 at 600 K. In addition, the AgMnGeSbTe4 exhibits a degenerate semiconductor behavior and a large average power factor of 10.36 µW cm−1 K−2 in the temperature range of 400–773 K. As a consequence, the AgMnGeSbTe4 has a peak figure of merit (ZT) of 1.05 at 773 K and a desirable average ZT value of 0.84 in the temperature range of 400–773 K. Moreover, the thermoelectric performance of AgMnGeSbTe4 can be further enhanced by precipitating of Ag8GeTe6, which acts as extra scatting centers for holes with low energy and phonons with medium wavelength. The simultaneous optimization in power factor and lattice thermal conductivity yields a peak ZT of 1.27 at 773 K and an average ZT of 0.92 (400–773 K) in AgMnGeSbTe4-1 mol% Ag8GeTe6. 相似文献
16.
Mingyue Han Yingrui Xiao Chao Zhou Zijie Xiao Wenyan Tan Guowei Yao Xiaoxue Wu Renzhong Zhuang Shiming Deng Qi Hu Yuxuan Yang Zhaoheng Tang Xunsheng Zhou Haobo Lin Huili Liang Shenghuang Lin Zengxia Mei Cailin Wang Qi Chen Wei Zhang Yan Jiang 《Advanced functional materials》2023,33(35):2303376
Organic-inorganic hybrid perovskites are promising candidates for direct X-ray detection and imaging. The relatively high dark current in perovskite single crystals (SCs) is a major limiting factor hindering the pursuit of performance and stability enhancement. In this study, the contribution of dark current is disentangled from electronic (σe) and ionic conductivity (σi) and shows that the high σi dominates the dark current of MAPbBr3 SCs. A multilayer heterojunctions passivation strategy is developed that suppresses not only the σi by two orders of magnitude but also σe by a factor of 1.6. The multilayer heterojunctions passivate the halide vacancy defects and increase the electron and hole injection barrier by inducing surface p-type doping of MAPbBr3. This enables the MAPbBr3 SC X-ray detectors to obtain a high sensitivity of 19 370 µC Gyair−1 cm−2 under a high electric field of 100 V cm−1, a record high sensitivity for bromine self-powered devices, and a low detection limit of 42.3 nGyair s−1. The unencapsulated detectors demonstrate a stable baseline after storage for 210 days and outstanding operational stability upon irradiation with an accumulated dose of up to 1944 mGyair. 相似文献
17.
Zhi Zheng Haiyang Li Liang Hai Ruiqi Ma Rui Liu Chunpeng Zhai Zongdong Sun Fei Wang Ying Ma Qingguo Xie Xiaoding Lou Tianyou Zhai Fan Xia 《Advanced functional materials》2024,34(1):2307093
2D perovskites have attracted wide attention for optoelectronic applications because of their unique layer structure and tunable outstanding optical/electrical properties. In addition, 2D Cs3Bi2Br9 nanoflakes possess large effective atomic number, high resistivity, high density as well as excellent stability, rendering it a promising material for X-ray detection. Nevertheless, it is full of challenges to synthesize 2D Cs3Bi2Br9 nanoflakes by conventional inversion temperature crystallization (ITC) strategy due to the existence of Br- vacancies in the Cs3Bi2Br9 crystal nucleus. Herein, an Ag+ assisted ITC (SAITC) strategy to grow 2D Cs3Bi2Br9 nanoflakes is proposed. The synthesis mechanism revealed by both experiments and theoretical calculations can be mainly ascribed to the passivated Br− vacancies and enhanced structure stability by adding Ag+ which can effectively prevent the oxidation of 2D Cs3Bi2Br9 nanoflakes from growth of hybrid crystals. The synthesized high-crystallinity 2D Cs3Bi2Br9 nanoflakes possess direct bandgap characteristic, and the mobility lifetime can reach 9.8 × 10−4 cm2 V−1. Excitingly, the fabricated device based on 2D Cs3Bi2Br9 nanoflakes demonstrates ultrahigh sensitivity of detecting X-ray (1.9 CGyair−1cm−2) at very low driven voltage (0.5 V) due to the photoconductive gain mechanism. The 2D Cs3Bi2Br9 nanoflakes synthesized by SAITC method have great potential for developing highly sensitive optoelectronic devices. 相似文献
18.
Chunyang Wang Cheng Hu Fang Chen Haitao Li Yihe Zhang Tianyi Ma Hongwei Huang 《Advanced functional materials》2023,33(29):2301144
Piezocatalytic pure water splitting for H2 evolution carries the virtues of efficacious utilization of mechanical energy, easy operation, and high value-added products, while lacking desirable piezoelectrics for high chemical energy production. Here, two polar layered bismuth-rich oxyhalides Bi4O5X2 (XBr, I) thin nanosheets (≈4 nm) are first exploited as efficient piezocatalysts to be capable of dissociating pure water. The unique asymmetrical layered structures of Bi4O5X2 (XBr, I) composed of the interleaved [Bi4O5]2+ layer and double X− ions slabs along the [1 0 1_] orientation cause large intrinsic dipole moment, excellent piezoelectricity and easy deformation. Without any cocatalyst and sacrificial agent, Bi4O5Br2 and Bi4O5I2 thin nanosheets display remarkable piezocatalytic H2 production rate of 1149.0 and 764.5 µmol g−1 h−1, respectively, standing among the best piezocatalysts, accompanied by H2O2 and hydroxyl radicals (·OH) as oxidative products. The smaller radius and higher electronegativity of interleaved Br than I cause a more strongly polar crystal structure in Bi4O5Br2, contributing to the higher piezocatalytic activity compared to Bi4O5I2. This study broadens the scope of piezoelectric materials applied to sustainable energy catalysis by efficiently converting mechanical energy and illustrates the importance of crystal configuration and composition in fabricating efficient piezocatalytic systems. 相似文献
19.
Ru Xiao Tong Yu Shan Yang Xiaoyin Zhang Tianzhao Hu Ruogu Xu Zhuoyan Qu Guangjian Hu Zhenhua Sun Feng Li 《Advanced functional materials》2024,34(3):2308210
The commonly used “catalyst on carbon” architecture as a sulfur host is difficult to jointly achieve high gravimetric and volumetric energy densities for lithium–sulfur (Li–S) batteries due to the contradiction between low tap density/poor catalytic activity of carbon and the easy agglomeration of metal-based compounds without carbon. Here, a non-carbon-dominated catalytic architecture using macroporous nickel/cobalt phosphide (NiCoP) is reported as the sulfur host for Li–S batteries. The macroporous framework, which accommodates a large amount of sulfur, can accelerate the electrochemical reaction kinetics by accelerated e− transport, Li+ diffusion, and superior adsorption and catalytic activity of inherent Ni2P/CoP heterostructures. The high tap density (0.45 g cm−3) and mechanically hard features contribute to the excellent structural and physicochemical stability of the NiCoP@S electrode after the pressing and rolling process. These features enable the Li–S coin cell to exhibit excellent electrochemical performance under conditions of high sulfur loading (10.2 mg cm−2) and lean electrolyte (electrolyte/sulfur of 2 µL mg−1). Inspiringly, the assembled pouch cell can simultaneously deliver a gravimetric energy density of 345.2 Wh kg−1 and an impressive volumetric energy density of 952.7 Wh L−1 based on the entire device configuration. 相似文献
20.
Novel hybrid dielectric film is synthesized at a low temperature of 150 °C using a solution process. Zirconium acrylate (ZrA) and poly(methyl methacrylate) (PMMA) comprise the inorganic and organic components, respectively. The acrylate-based molecular structure of both ingredients allows the facile formation of hybrid ZrA/PMMA dielectric film with neither additional coupling agent nor ultraviolet photon irradiation. The high quality of the hybrid ZrA/PMMA dielectric film is confirmed by its high dielectric constant of 5.5 and low leakage current density of 1.7 × 10−8 A/cm2 at the electric field of 1 MV/cm. The indium gallium tin oxide (IGTO) transistors with the optimal ZrA/PMMA gate insulator layer are fabricated on the polyimide substrate at the maximum high temperature of 150 °C. They exhibit hysteresis-free high performance with high carrier mobility of 24.3 cm2V−1s−1, gate swing of 0.61 V/decade and ION/OFF ratio of 4 × 106. Owing to the intrinsic deformability of hybrid dielectric film, these transistors maintained electrical performance after 100 cycles of mechanical bending to the extremely small radius of curvature of 2 mm. 相似文献