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1.
Plasmonic Au/TiO2‐Dumbbell‐On‐Film Nanocavities for High‐Efficiency Hot‐Carrier Generation and Extraction
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Kwun Hei Willis Ho Aixue Shang Fenghua Shi Tsz Wing Lo Pui Hong Yeung Yat Sing Yu Xuming Zhang Kwok‐yin Wong Dang Yuan Lei 《Advanced functional materials》2018,28(34)
Plasmon‐induced hot carriers have vast potential for light‐triggered high‐efficiency carrier generation and extraction, which can overcome the optical band gap limit of conventional semiconductor‐based optoelectronic devices. Here, it is demonstrated that Au/TiO2 dumbbell nanostructures assembled on a thin Au film serve as an efficient optical absorber and a hot‐carrier generator in the visible region. Upon excitation of localized surface plasmons in such coupled particle‐on‐film nanocavities, the energetic conduction electrons in Au can be injected over the Au/TiO2 Schottky barrier and migrated to TiO2, participating in the chemical reaction occurring at the TiO2 surface. Compared with the same dumbbell nanostructures on an indium tin oxide (ITO) film, such nanocavities exhibit remarkable enhancement in both photocurrent amplitude and reaction rate that arise from increased light absorption and near‐field amplification in the presence of the Au film. The incident‐wavelength‐dependent photocurrent and reaction rate measurements jointly reveal that Au‐film‐mediated near‐field localization facilitates more efficient electron–hole separation and transport in the dumbbells and also promotes strong d‐band optical transitions in the Au film for generation of extra hot electrons. Such nanocavities provide a new plasmonic platform for effective photoexcitation and extraction of hot carriers and also better understanding of their fundamental science and technological implications in solar energy harvesting. 相似文献
2.
Self‐Assembly of Flexible Free‐Standing 3D Porous MoS2‐Reduced Graphene Oxide Structure for High‐Performance Lithium‐Ion Batteries
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Yunfeng Chao Rouhollah Jalili Yu Ge Caiyun Wang Tian Zheng Kewei Shu Gordon G. Wallace 《Advanced functional materials》2017,27(22)
Flexible freestanding electrodes are highly desired to realize wearable/flexible batteries as required for the design and production of flexible electronic devices. Here, the excellent electrochemical performance and inherent flexibility of atomically thin 2D MoS2 along with the self‐assembly properties of liquid crystalline graphene oxide (LCGO) dispersion are exploited to fabricate a porous anode for high‐performance lithium ion batteries. Flexible, free‐standing MoS2–reduced graphene oxide (MG) film with a 3D porous structure is fabricated via a facile spontaneous self‐assembly process and subsequent freeze‐drying. This is the first report of a one‐pot self‐assembly, gelation, and subsequent reduction of MoS2/LCGO composite to form a flexible, high performance electrode for charge storage. The gelation process occurs directly in the mixed dispersion of MoS2 and LCGO nanosheets at a low temperature (70 °C) and normal atmosphere (1 atm). The MG film with 75 wt% of MoS2 exhibits a high reversible capacity of 800 mAh g?1 at a current density of 100 mA g?1. It also demonstrates excellent rate capability, and excellent cycling stability with no capacity drop over 500 charge/discharge cycles at a current density of 400 mA g?1. 相似文献
3.
Flexible broadband photodetectors based on 2D MoS2 have gained significant attention due to their superior light absorption and increased light sensitivity. However, pristine MoS2 has absorption only in visible and near IR spectrum. This paper reports a paper‐based broadband photodetector having ZnS–MoS2 hybrids as active sensing material fabricated using a simple, cost effective two‐step hydrothermal method wherein trilayer MoS2 is grown on cellulose paper followed by the growth of ZnS on MoS2. Optimization in terms of process parameters is done to yield uniform trilayer MoS2 on cellulose paper. UV sensing property of ZnS and broadband absorption of MoS2 in visible and IR, broadens the range from UV to near IR. ZnS plays the dual role for absorption in UV and in the generation of local electric fields, thereby increasing the sensitivity of the sensor. The fabricated photodetector exhibits a higher responsivity toward the visible light when compared to UV and IR light. Detailed studies in terms of energy band diagram are presented to understand the charge transport mechanism. This represents the first demonstration of a paper‐based flexible broadband photodetector with excellent photoresponsivity and high bending capability that can be used for wearable electronics, flexible security, and surveillance systems, etc. 相似文献
4.
Yufan Ji Mengchen Zhang Kecheng Guan Jing Zhao Gongping Liu Wanqin Jin 《Advanced functional materials》2019,29(33)
Thin film composite (TFC) membranes have attracted great research interest for a wide range of separation processes owing to their potential to achieve excellent permeance. However, it still remains challenging to fully exploit the superiority of thin selective layers when mitigating the pore intrusion phenomenon. Herein, a facile and generic interface‐decoration‐layer strategy collaborating with molecular‐scale organic–inorganic hybridization in the selective layer to obtain a high‐performance ultrathin film composite (UTFC) membrane for CO2 capture is reported. The interface‐decoration layer of copper hydroxide nanofibers (CHNs) enables the formation of an ultrathin selective layer (≈100 nm), achieving a 2.5‐fold increase in gas permeance. The organic part in the molecular‐scale hybrid material contributes to facilitating CO2‐selective adsorption while the inorganic part assists in maintaining robust membrane structure, thus remarkably improving the selectivity toward CO2. As a result, the as‐prepared membrane shows a high CO2 permeance of 2860 GPU, superior to state‐of‐the‐art polymer membranes, with a CO2/N2 selectivity of 28.2. The synergistic strategy proposed here can be extended to a wide range of polymers, holding great potential to produce high‐efficiency ultrathin membranes for molecular separation. 相似文献
5.
Hao-Sen Kang Jing-Wen Zou Yang Liu Liang Ma Jing-Ru Feng Zi-Yang Yu Xiang-Bai Chen Si-Jing Ding Li Zhou Qu-Quan Wang 《Advanced functional materials》2023,33(44):2303911
A three-plasmon hybrid, in which core–shell Au@Cu2−xS hybrids are bonded with ultrathin Ti3C2Tx MXene, is prepared for high-efficiency photothermal conversion and membrane-based solar water evaporation for the first time. The MXene/Au nanorod@Cu2−xS hybrids display excellent photothermal conversion efficiency under irradiation of an 808 laser, causing by the three-plasmon-induced synergistic plasmonic absorption and heating effects as well as the multichannel charge transfer between the components. Then, Au nanosphere@Cu2−xS and Au nanorod@Cu2−xS hybrids are mixed and combined with MXene to serve as the membrane material, which shows excellent light absorption ranging from ultraviolet to near-infrared region. By transferring the membrane materials on a hydrophilic cotton piece, the as-prepared photothermal membrane displays a high evaporation rate of 2.023 kg m−2 h−1 and light-to-heat conversion efficiency of 96.1% under 1-sun irradiation due to the synergistic photothermal conversion and over 96% of solar light absorption efficiency. Furthermore, a home-made solar evaporation device enabling automatic inflow of untreated water and outflow of evaporated water is designed based on the principles of liquid pressure and connectors. The seawater desalination and sewage treatment experiments performed on the device and membrane indicate the great potential in solar-light-driven water purification and drinkable water generation. 相似文献
6.
Wei Zheng Junhao Lin Wei Feng Kai Xiao Yunfeng Qiu XiaoShuang Chen Guangbo Liu Wenwu Cao Sokrates T. Pantelides Wu Zhou PingAn Hu 《Advanced functional materials》2016,26(35):6371-6379
2D layered MoS2 has drawn intense attention for its applications in flexible electronic, optoelectronic, and spintronic devices. Most of the MoS2 atomic layers grown by conventional chemical vapor deposition techniques are n‐type due to the abundant sulfur vacancies. Facile production of MoS2 atomic layers with p‐type behavior, however, remains challenging. Here, a novel one‐step growth has been developed to attain p‐type MoS2 layers in large scale by using Mo‐containing sol–gel, including 1% tungsten (W). Atomic‐resolution electron microscopy characterization reveals that small tungsten oxide clusters are commonly present on the as‐grown MoS2 film due to the incomplete reduction of W precursor at the reaction temperature. These omnipresent small tungsten oxide clusters contribute to the p‐type behavior, as verified by density functional theory calculations, while preserving the crystallinity of the MoS2 atomic layers. The Mo containing sol–gel precursor is compatible with the soft‐lithography techniques, which enables patterned growth of p‐type MoS2 atomic layers into regular arrays with different shapes, holding great promise for highly integrated device applications. Furthermore, an atomically thin p–n junction is fabricated by the as‐prepared MoS2, which shows strong rectifying behavior. 相似文献
7.
Fan Gong Wenjin Luo Jianlu Wang Peng Wang Hehai Fang Dingshan Zheng Nan Guo Jingli Wang Man Luo Johnny C. Ho Xiaoshuang Chen Wei Lu Lei Liao Weida Hu 《Advanced functional materials》2016,26(33):6084-6090
In recent years, 2D layered materials have been considered as promising photon absorption channel media for next‐generation phototransistors due to their atomic thickness, easily tailored single‐crystal van der Waals heterostructures, ultrafast optoelectronic characteristics, and broadband photon absorption. However, the photosensitivity obtained from such devices, even under a large bias voltage, is still unsatisfactory until now. In this paper, high‐sensitivity phototransistors based on WS2 and MoS2 are proposed, designed, and fabricated with gold nanoparticles (AuNPs) embedded in the gate dielectric. These AuNPs, located between the tunneling and blocking dielectric, are found to enable efficient electron trapping in order to strongly suppress dark current. Ultralow dark current (10?11 A), high photoresponsivity (1090 A W?1), and high detectivity (3.5 × 1011 Jones) are obtained for the WS2 devices under a low source/drain and a zero gate voltage at a wavelength of 520 nm. These results demonstrate that the floating‐gate memory structure is an effective configuration to achieve high‐performance 2D electronic/optoelectronic devices. 相似文献
8.
Xiangming Xu Gobind Das Xin He Mohamed Nejib Hedhili Enzo Di Fabrizio Xixiang Zhang Husam N. Alshareef 《Advanced functional materials》2019,29(32)
To realize multifunctional devices at the wafer scale, the growth process of monolayer (ML) 2D semiconductors must meet two key requirements: 1) growth of continuous and homogeneous ML film at the wafer scale and 2) controllable tuning of the properties of the ML film. However, there is still no growth method available that fulfills both of these criteria. Here, the first report is presented on the preparation of continuous and uniform ML MoS2 films through a two‐step process at the wafer scale. Unlike in previous ML MoS2 film growth processes, the ML MoS2 film can be uniformly modulated across the wafer in terms of material structure and composition, exciton state, and electronic transport performance. A significant result is that the high‐quality wafer‐scale ML MoS2 films realize superior electronic performance compared to reported two‐step‐grown films, and it even matches or exceeds reported ML MoS2 films prepared by other processes. The transistor performance of the optimized ML film achieves a field effect mobility of 10 to 30 cm2 V?1 s?1, an on/off current ratio of about 107, and hysteresis as low as 0.4 V. 相似文献
9.
Fluorescent Block Copolymer‐MoS2 Nanocomposites for Real‐Time Photothermal Heating and Imaging
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Chan Ho Park Hongseok Yun Hyunseung Yang Junhyuk Lee Bumjoon J. Kim 《Advanced functional materials》2017,27(5)
Novel self‐monitoring photothermal (PT) agents are developed using optothermally responsive block copolymer‐MoS2 composites (BCP‐MoS2), which enable simultaneous PT heating and imaging of temperature profiles. In particular, upon near‐infrared light exposure, PT energy from MoS2 successfully increases local temperature and induces thermally activated conformational transitions of the BCP on MoS2. This leads to fluorescent signal changes caused by distance‐dependent Förster resonance energy transfer between the BCP and MoS2. Importantly, it is demonstrated that the use of BCP‐MoS2 for PT heating and optical mapping is fully reversible with excellent stability. The detailed mechanism of the responsive behavior of BCP‐MoS2 is elucidated by measurements of time‐resolved fluorescence and dynamic light scattering. In addition, the BCP‐MoS2 system is integrated into organogel matrices to demonstrate its potential as aportable, self‐monitoring PT system suitable for biological and environmental applications. 相似文献
10.
Fan Lu Meng Minmin Gao Tianpeng Ding Gamze Yilmaz Wei Li Ong Ghim Wei Ho 《Advanced functional materials》2020,30(32)
Capturing solar energy for thermal conversion in a highly efficient manner for steam‐electricity cogeneration is particularly opportune in the context of optimal solar energy utilization for concurrent water‐energy harvesting. Herein, an integrative photothermal evaporator/thermogalvanic cell with the desired optical, heat, water, and electrochemical management for synergistic steam‐electricity production is reported. Versatile layer by‐layer assembly is employed to integrate a hydrogel/metal‐oxide/polymer into a multilayer film with individually addressable thickness, composition, and structure. As such, the ultimate integrative multilayer film cell demonstrates a unified high surface area and conductive electrodes, broadband absorption, rapid water suction‐ion exchange, and thermal insulation properties. Thus, the designed cell immensely suppresses heat losses, achieving a high solar thermal conversion efficiency of 91.4% and maximum power outputs of ≈1.6 mW m?2. Additionally, the self‐floating, deformable, modular integral device presents appealing attributes such as salt‐rejection for viable seawater desalination, high mechanical stability, and resilience to demanding operating conditions, and configurable on‐demand/point‐of‐use tandem structure to maximize clean water and power generation value per area. This integrated strategy may provide prospective opportunities to reduce dependence on fossil fuels and freshwater inputs and solutions for renewable and decentralized clean water and electricity. 相似文献
11.
Ultrathin MoS2 Nanosheets@Metal Organic Framework‐Derived N‐Doped Carbon Nanowall Arrays as Sodium Ion Battery Anode with Superior Cycling Life and Rate Capability
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This study reports the design and fabrication of ultrathin MoS2 nanosheets@metal organic framework‐derived N‐doped carbon nanowall array hybrids on flexible carbon cloth (CC@CN@MoS2) as a free‐standing anode for high‐performance sodium ion batteries. When evaluated as an anode for sodium ion battery, the as‐fabricated CC@CN@MoS2 electrode exhibits a high capacity (653.9 mA h g?1 of the second cycle and 619.2 mA h g?1 after 100 cycles at 200 mA g?1), excellent rate capability, and long cycling life stability (265 mA h g?1 at 1 A g?1 after 1000 cycles). The excellent electrochemical performance can be attributed to the unique 2D hybrid structures, in which the ultrathin MoS2 nanosheets with expanded interlayers can provide shortened ion diffusion paths and favorable Na+ insertion/extraction space, and the porous N‐doped carbon nanowall arrays on flexible carbon cloth are able to improve the conductivity and maintain the structural integrity. Moreover, the N‐doping‐induced defects also make them favorable for the effective storage of sodium ions, which enables the enhanced capacity and rate performance of MoS2. 相似文献
12.
Activating Basal Planes and S‐Terminated Edges of MoS2 toward More Efficient Hydrogen Evolution
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Xiaolei Huang Mei Leng Wen Xiao Meng Li Jun Ding Teck Leong Tan Wee Siang Vincent Lee Junmin Xue 《Advanced functional materials》2017,27(6)
Molybdenum disulfide (MoS2) has been considered as a promising alternative to platinum (Pt)‐based catalyst for hydrogen evolution reaction (HER) due to its low cost and high catalytic activity. However, stable 2H phase of MoS2 (2H‐MoS2) exhibits low catalytic activity in HER due to the inert basal plane and S‐edge. Thus, to exploit the basal plane and S‐edge for additional electrocatalytic activity, a facile strategy is developed to prepare P‐doped 2H‐MoS2 film on conductive substrate via low‐temperature heat treatment. Due to the inherent difficulty of P‐doping into MoS2 crystal structure, oxygen (O)‐doping is utilized to aid the P‐doping process, as supported by the first‐principles calculations. Interestingly, P‐doping could dramatically reduce Mo valence charge, which results in the functionalization of the inert MoS2 basal plane and S‐edge. In agreement with simulation results, P‐doped 2H‐MoS2 electrode exhibits enhanced catalytic performance in H2 generation with low onset potential (130 mV) and small Tafel slope of 49 mV dec?1. The enhanced catalytic performance arises from the synergistic effect of the activated basal plane, S‐edge, and Mo‐edge sites, leading to favorable hydrogen adsorption energies. Most importantly, improved cyclic stability is achieved, which reveals chemically inert properties of P‐doped 2H‐MoS2 in acidic electrolyte. 相似文献
13.
A pH responsive, chitosan‐based hydrogel film is used to cap the pores of a porous SiO2 layer. The porous SiO2 layer is prepared by thermal oxidation of an electrochemically etched Si wafer, and the hydrogel film is prepared by reaction of chitosan with glycidoxypropyltrimethoxysilane (GPTMS). Optical reflectivity spectroscopy and scanning electron microscopy (SEM) confirm that the bio‐polymer only partially infiltrates the porous SiO2 film, generating a double layer structure. The optical reflectivity spectrum displays Fabry–Pérot interference fringes characteristic of a double layer, which is characterized using reflective interferometric Fourier transform spectroscopy (RIFTS). Monitoring the position of the RIFTS peak corresponding to the hydrogel layer allows direct, real‐time observation of the reversible volume phase transition of the hydrogel upon cycling of pH in the range 6.0–7.4. The swelling ratio and response time are controlled by the relative amount of GPTMS in the hydrogel. The pH‐dependent volume phase transition can be used to release insulin trapped in the porous SiO2 layer underneath the hydrogel film. At pH 7.4, the gel in the top layer effectively blocks insulin release, while at pH 6.0 insulin penetrates the swollen hydrogel layer, resulting in a steady release into solution. 相似文献
14.
MoS2/Si Heterojunction with Vertically Standing Layered Structure for Ultrafast,High‐Detectivity,Self‐Driven Visible–Near Infrared Photodetectors
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Liu Wang Jiansheng Jie Zhibin Shao Qing Zhang Xiaohong Zhang Yuming Wang Zheng Sun Shuit‐Tong Lee 《Advanced functional materials》2015,25(19):2910-2919
As an interesting layered material, molybdenum disulfide (MoS2) has been extensively studied in recent years due to its exciting properties. However, the applications of MoS2 in optoelectronic devices are impeded by the lack of high‐quality p–n junction, low light absorption for mono‐/multilayers, and the difficulty for large‐scale monolayer growth. Here, it is demonstrated that MoS2 films with vertically standing layered structure can be deposited on silicon substrate with a scalable sputtering method, forming the heterojunction‐type photodetectors. Molecular layers of the MoS2 films are perpendicular to the substrate, offering high‐speed paths for the separation and transportation of photo‐generated carriers. Owing to the strong light absorption of the relatively thick MoS2 film and the unique vertically standing layered structure, MoS2/Si heterojunction photodetectors with unprecedented performance are actualized. The self‐driven MoS2/Si heterojunction photodetector is sensitive to a broadband wavelength from visible light to near‐infrared light, showing an extremely high detectivity up to ≈1013 Jones (Jones = cm Hz1/2 W?1), and an ultrafast response speed of ≈3 μs. The performance is significantly better than the photodetectors based on mono‐/multilayer MoS2 nanosheets. Additionally, the MoS2/Si photodetectors exhibit excellent stability in air for a month. This work unveils the great potential of MoS2/Si heterojunction for optoelectronic applications. 相似文献
15.
Yongpeng Cui Wei Liu Wenting Feng Yuan Zhang Yongxu Du Shuang Liu Huanlei Wang Ming Chen Junan Zhou 《Advanced functional materials》2020,30(10)
The large volume expansion induced by K+ intercalation is always a big challenge for designing high‐performance electrode materials in potassium‐ion storage system. Based on the idea that large‐sized ions should accommodate big “houses,” a facile‐induced growth strategy is proposed to achieve the self‐loading of MoS2 clusters inside a hollow tubular carbon skeleton (HTCS). Meantime, a step‐by‐step intercalation technology is employed to tune the interlayer distance and the layer number of MoS2. Based on the above, the ED‐MoS2@CT hybrids are achieved by self‐loading and anchoring the well‐dispersed ultrathin MoS2 nanosheets on the inner surface of HTCSs. This unique compositing model not only alleviates the mechanical strain efficiently, but also provides spacious “roads” (hollow tubular carbon skeleton) and “houses” (interlayer expanded ultrathin MoS2 sheets) for fast K+ transition and storage. As an anode of potassium‐ion batteries, the resultant ED‐MoS2@CT electrode delivers a high specific capacity of 148.5 mAh g?1 at 2 A g?1 after 10 000 cycles with only 0.002% fading per cycle. The assembled ED‐MoS2@CT//PC potassium‐ion hybrid supercapacitor device shows a high energy density of 148 Wh kg?1 at a power density of 965 W kg?1, which is comparable to that of lithium‐ion hybrid supercapacitors. 相似文献
16.
Yagang Yao Lorenzo Tolentino Zhongzheng Yang Xiaojuan Song Wen Zhang Yongsheng Chen Ching‐ping Wong 《Advanced functional materials》2013,23(28):3577-3583
Molybdenum disulfide (MoS2) nanosheets have been attracting increasing research interests due to their unique material properties. However, the lack of a reliable large‐scale production method impedes their practical applications. Here a facile, efficient, and scalable method for the fabrication of high‐concentration aqueous dispersion of MoS2 nanosheets using combined grinding and sonication is reported. The 26.7 ± 0.7 mg/mL concentration achieved is the highest concentration in an aqueous solution reported up to now. Grinding generates pure shear forces to detach the MoS2 layers from the bulk materials. Subsequent sonication further breaks larger crystallites into smaller crystallites, which promotes the dispersion of MoS2 nanosheets in ethanol/water solutions. The exfoliation process establishes a new paradigm in the top‐down fabrication of 2D nanosheets in aqueous solution. In the meantime, MoS2‐based sensing film produced using this approach has successfully demonstrated the feasibility of a low‐cost and efficient NH3 gas sensor using inkjet printing as a viable method. 相似文献
17.
Kee‐Jeong Yang Jun‐Hyoung Sim Boram Jeon Dae‐Ho Son Dae‐Hwan Kim Shi‐Joon Sung Dae‐Kue Hwang Soomin Song Dhruba B. Khadka JunHo Kim Jin‐Kyu Kang 《Progress in Photovoltaics: Research and Applications》2015,23(7):862-873
Cu2ZnSnS4 (CZTS)‐based materials have a useful band gap and a high absorption coefficient; however, their power conversion efficiency is low compared with that of CdTe and Cu(In,Ga)Se2‐based solar cells. Two of the factors that strongly affect CZTS solar cell characteristics are the MoS2 layer and the presence of defects. In this study, Mo back‐contact layers were annealed to control MoS2 layer formation and the Na content in the Mo layer before the absorber precursor layer was deposited. The increase in oxygen content in the Mo layer suppressed MoS2 layer formation. In addition, the increase in Na diffusion during the initial stage of the absorber precursor deposition decreased the defect density in the absorber layer and in the absorber–buffer interface. These results were verified through measurements of the external quantum efficiency, the temperature dependence of the open‐circuit voltage (VOC), and admittance spectra. The current densities (JSC) and VOC, as well as the power conversion efficiencies, improved as the annealing temperature of the Mo layer increased, which suggests that CZTS solar cell characteristics can be improved by suppressing MoS2 layer formation and increasing Na content in the Mo layer before deposition of the absorber precursor layer. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
18.
Wenchao Wang Sai Zhu Yingnan Cao Ying Tao Xin Li Donglai Pan David Lee Phillips Dieqing Zhang Ming Chen Guisheng Li Hexing Li 《Advanced functional materials》2019,29(36)
Exploring TiO2‐photocatalysts for sunlight conversion has high demand in artificial photosynthesis. In this work, edge‐enriched ultrathin molybdenum disulfide (MoS2) flakes are uniformly embedded into the bulk of yolk‐shell TiO2 as a cocatalyst to accelerate photogenerated‐electron transfer from the bulk to the surface of TiO2. The as‐formed MoS2/TiO2 (0.14 wt%) hybrids exhibit a high hydrogen evolution rate (HER) of 2443 µmol g?1 h?1, about 1000% and 470% of that of pristine TiO2 (247 µmol g?1 h?1) and bulk MoS2 decorated TiO2 (513 µmol g?1 h?1). Such a greatly enhanced HER is attributed to the exposed catalytic edges of the ultrathin MoS2 flakes with a robust chemical linkage (Ti? S bond), providing rapid charge transfer channels between TiO2 and MoS2. The catalytic stability is promoted by the antiaggregation of the highly dispersed MoS2 flakes in the bulk of yolk‐shell TiO2. The exponential fitted decay kinetics of time‐resolved photoluminescence (ns‐PL) spectra illustrates that embedding ultrathin MoS2 flakes in TiO2 effectively decreases the average lifetime of PL in the MoS2/TiO2 hybrids (τave = 4.55 ns), faster than that of pristine TiO2 (≈7.17 ns) and the bulk MoS2/TiO2 (≈6.13 ns), allowing a superior charge separation and charge trapping process for reducing water. 相似文献
19.
Low‐voltage, hysteresis‐free, flexible thin‐film‐type electronic systems based on networks of single‐walled carbon nanotubes and bilayer organic–inorganic nanodielectrics are detailed in work by Rogers and co‐workers reported on p. 2355. The cover image shows a schematic array of such thin‐film transistors (TFTs) on a plastic substrate. The structure of the bilayer nanodielectric, which consists of a film of HfO2 formed by atomic layer deposition and an ultrathin layer of epoxy formed by spin‐casting, is also illustrated schematically. High‐capacitance bilayer dielectrics based on atomic‐layer‐deposited HfO2 and spin‐cast epoxy are used with networks of single‐walled carbon nanotubes (SWNTs) to enable low‐voltage, hysteresis‐free, and high‐performance thin‐film transistors (TFTs) on silicon and flexible plastic substrates. These HfO2–epoxy dielectrics exhibit excellent properties including mechanical flexibility, large capacitance (up to ca. 330 nF cm–2), and low leakage current (ca. 10–8 A cm–2); their low‐temperature (ca. 150 °C) deposition makes them compatible with a range of plastic substrates. Analysis and measurements of these dielectrics as gate insulators in SWNT TFTs illustrate several attractive characteristics for this application. Their compatibility with polymers used for charge‐transfer doping of SWNTs is also demonstrated through the fabrication of n‐channel SWNT TFTs, low‐voltage p–n diodes, and complementary logic gates. 相似文献
20.
Poly(m‐aminobenzene sulfonic acid) (PABS), was covalently bonded to single‐walled carbon nanotubes (SWNTs) to form a water‐soluble nanotube–polymer compound (SWNT–PABS). The conductivity of the SWNT–PABS graft copolymer was about 5.6 × 10–3 S cm–1, which is much higher than that of neat PABS (5.4 × 10–7 S cm–1). The mid‐IR spectrum confirmed the formation of an amide bond between the SWNTs and PABS. The 1H NMR spectrum of SWNT–PABS showed the absence of free PABS, while the UV/VIS/NIR spectrum of SWNT–PABS showed the presence of the interband transitions of the semiconducting SWNTs and an absorption at 17 750 cm–1 due to the PABS addend. 相似文献