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a) Schematics of guided Li nucleation and deposition on surface of engineered CC. SEM images of pristine CC/Cu/Cu2O with b) no Li deposition, c) 0.2 mAh cm⁻² of Li uniformly nucleated on surface CC/Cu/Cu2O, and d) 2 mAh cm⁻² of Li plated on CC/Cu/Cu2O (insets are corresponding cross‐sectional SEM images showing the uniform Li nucleation and plating). e) SEM images of control samples of original CC with no surface engineering, f) 0.2 mAh cm⁻² of Li unevenly nucleated on original CC, and g) 2 mAh cm⁻² of Li unevenly plated on original CC.
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Carbon materials have been ubiquitously applied in energy conversion and storage devices owing to their high conductivity, excellent stability, and flexible structure. Conventional functionalization of carbon materials typically involves complex chemical treatment or long‐term thermal and hydrothermal modifications. Here, a one‐step universal strat...
Citations
... NiFe@DG was synthesized via a microwave thermal shock treatment employing a solid composite (denoted as NiFe LDH/G) of NiFe LDH and reduced graphene oxide (rGO) as the precursor, which was prepared by a hydrothermal method (Figure 1a). During the microwave shock, a transient high temperature (>1000°C) 30 could be instantly generated with intensive lighting ( Figure S1), resulting in the fast decomposition of NiFe LDH and the formation of NiFe nanoalloys. Meanwhile, carbon-containing fragments generated from the high-temperature reduction of the rGO substrate provided carbon sources to grow thin and defective graphene shells under the catalytic effects of the NiFe nanoalloys, resulting in the formation of core−shell nanoparticles. ...
... Aqueous supercapacitors are critical energy storage devices for applications that require high power density and long cycle lifetime, such as regenerative braking systems in electric vehicles, uninterruptible power supplies, and power levelers for electronics [1][2][3][4] . With the fast development of supercapacitors, diverse materials including porous carbons, metal oxides/carbides/nitrides, and conductive polymers have been optimized to pursue a higher energy density in supercapacitors, among which porous carbons are still the primary and widely used active materials for commercial aqueous supercapacitors 3,[5][6][7][8][9] . The advantages of porous carbons for supercapacitors include power capability, long-term cycle stability, wide operating temperatures, and high Coulombic efficiencies [10][11][12][13] . ...
... In (c-f), the error bars indicate the standard deviations of the parameters determined by fitting the data with Eqs. (4)(5)(6). electrolytes within the carbons as both the slow and the fast components are faster in C-Phl-700 as compared with C-Phl. C-Phl immobilizes a larger content of the electrolyte on the carbon walls. ...
Porous carbons are the active materials of choice for supercapacitor applications because of their power capability, long-term cycle stability, and wide operating temperatures. However, the development of carbon active materials with improved physicochemical and electrochemical properties is generally carried out via time-consuming and cost-ineffective experimental processes. In this regard, machine-learning technology provides a data-driven approach to examine previously reported research works to find the critical features for developing ideal carbon materials for supercapacitors. Here, we report the design of a machine-learning-derived activation strategy that uses sodium amide and cross-linked polymer precursors to synthesize highly porous carbons (i.e., with specific surface areas > 4000 m²/g). Tuning the pore size and oxygen content of the carbonaceous materials, we report a highly porous carbon-base electrode with 0.7 mg/cm² of electrode mass loading that exhibits a high specific capacitance of 610 F/g in 1 M H2SO4. This result approaches the specific capacitance of a porous carbon electrode predicted by the machine learning approach. We also investigate the charge storage mechanism and electrolyte transport properties via step potential electrochemical spectroscopy and quasielastic neutron scattering measurements.
... Later, in 2021, Zhong et al. deposited metal nanoparticles onto the surface of carbon fiber clothes by heating metal salts-coated carbon fiber clothes to 1500 K within 5 s by 900 W microwave heating. [27] The resulting composite showed good performance as the anode in Li metal batteries. ...
... The resulting metal/carbon hybrids were used as anodes in Li metal batteries. [27] ...
High‐temperature thermal treatment is a standard step in the synthesis of many materials. In recent years, ultrafast heating methods, such as Joule heating, laser, light, or microwave irradiations, have been used to create novel carbon materials and carbon/metal hybrid structures, demonstrating unique and often superior properties compared to those synthesized by conventional heating methods. They have shown promising application potentials in catalysis, batteries, supercapacitors, fuel cells, sensors, implants, actuators, lighting devices, and waste recycling. Here, we review recent findings in creating novel carbon and carbon/metal hybrid structures by ultrafast heating methods. We first describe the most frequently used ultrafast heating methods, their advantages, and their limitations. Then, we summarize different carbon structures created by these methods, including graphene, reduced graphene oxide, hard carbon, carbon nanotube architectures, and other carbon hybrids. Next, we review novel carbon/metal hybrid structures, including carbon‐supported nanoparticles of mono‐metal, metal alloy, metal composite, high entropy alloy, and single‐atom catalysts. We focus on heating methods, critical precursors used, synthesis parameters affecting material structures, and mechanistic understanding of their unique synthesis processes. The essential properties of these novel structures and their applications are also summarized. Finally, we discuss knowledge gaps and technical challenges in employing these methods for scalable material production. This article is protected by copyright. All rights reserved.
... Carbon materials are good absorbents of microwaves that can be rapidly heated by microwave radiation, which is called microwave-induced carbothermal shock. [28] In a typical ultrafast Long processing time and high temperatures are often required in sintering ceramic electrolytes, which lead to volatile element loss and high cost. Here, an ultrafast sintering method of microwave-induced carbothermal shock to fabricate various ceramic electrolytes in seconds is reported. ...
Long processing time and high temperatures are often required in sintering ceramic electrolytes, which lead to volatile element loss and high cost. Here, we report an ultrafast sintering method of microwave‐induced carbothermal shock to fabricate various ceramic electrolytes in seconds. Furthermore, it is also able to integrate electrode and electrolyte in one step by simultaneous co‐sintering. Based on this ultrafast co‐sintering technique, an all‐solid‐state lithium‐metal battery with a high areal capacity is successfully achieved, realizing a promising electrochemical performance at room temperature. This method can extend to other various ceramic multilayer based solid devices. This article is protected by copyright. All rights reserved
... In our recent research, it has been proposed that multi-metallic nanoparticles, so-called highentropy-alloy nanoparticles (HEA-NPs) [12][13][14][15], are one of the most promising candidates for tailoring the optical absorption property [16,17]. Such a performance is induced by the reinforced interband transitions (IBTs), contributed by the fully filled energy regions around the Fermi level [12,18]. ...
Multi-metallic nanoparticles have been proven to be an efficient photothermal conversion material, for which the optical absorption can be broadened through the interband transitions (IBTs), but it remains a challenge to make the composition homogeneous distributing within the immiscible combinations. Here, assisted with the extreme-high evaporated temperature, ultra-fast cooling, and vapor-pressure strategy, the arc-discharged plasma method was employed to synthesize the ultra-mixed multi-metallic nanoparticles compositing with 21 elements (FeCoNiCrYTiVCuAlNbMoTaWZnCdPbBiAgInMnSn), in which the strongly repelling combinations were uniformly distributed. Due to the reinforced lattice distortion effect and excellent IBTs, the nanoparticles can realize an average absorption greater than 92% in the entire solar spectrum (250 to 2500 nm). In particular, the 21-element nanoparticles achieve a considerably high solar steam efficiency of near 99% under one solar irradiation, with a water evaporation rate of 2.42 kg m−2 h−1, demonstrating a highly efficient photothermal conversion performance. The present approach opens a new strategy for uniformly mixing multi-metallic elements for exploring their unknown properties and various applications.
... [8] Moreover, many researches used the MW-induced hot spots as heat source to induce reactions, because the ultra-fast heating rate of MW-absorbing particles under MW irradiation can achieve locally high temperature within minutes. [9] For instance, Huang et al. [10] used MW-induced micro-hot spots to fabricate carbon fiber-supported cobalt nanocatalysts, where the randomly stacked graphene powder in MW field acted as heating source for the pyrolysis of MOF precursors attached on the graphene powder. The carbon materials have strong ability to transform MW energy into Joule heat through the collision of π-electrons and carbon atoms. ...
Mikrowellenchemie. In ihrem Forschungsartikel (e202114340) berichten Hong Li, Xin Gao et al. über den Nachweis von mikrowelleninduzierten Hot Spots in flüssigen Lösungen mithilfe eines Fluoreszenzthermometers, das an mikrowellenabsorbierenden Kohlenstoffpartikeln angebracht ist.
... [8] Moreover, many researches used the MW-induced hot spots as heat source to induce reactions, because the ultra-fast heating rate of MW-absorbing particles under MW irradiation can achieve locally high temperature within minutes. [9] For instance, Huang et al. [10] used MW-induced micro-hot spots to fabricate carbon fiber-supported cobalt nanocatalysts, where the randomly stacked graphene powder in MW field acted as heating source for the pyrolysis of MOF precursors attached on the graphene powder. The carbon materials have strong ability to transform MW energy into Joule heat through the collision of π-electrons and carbon atoms. ...
Microwave Chemistry. In their Research Article (e202114340), Hong Li, Xin Gao et al. report the detection of microwave‐induced hot spots in liquid solutions with a fluorescence thermometer attached on microwave‐absorbing carbon particles.
... IL, composed of numerous anions and cations, has a strong polarity, which can strongly absorb the MW energy [37,38]. Such distinction enables the sufficient conversion of the MW energy to the kinetic energy of IL, more specifically, the MW radiation polarizes IL to induce the intense thermal motion of ions (it can have a swing frequency of 4.9 × 10 9 times per second at a 2450 MHz MW field) [40], and finally heat the IL system [41][42][43]. We investigated the MW-heating process by employing an infrared thermometer (Fig. 2a-c). ...
Natural cellulosic fibers/aggregates, being the most abundant eco-friendly resource, are a promising material solution toward the carbon neutrality and sustainability of our society. Further functionalization is required for their value-added applications but often involves complicated operations, high cost or toxic chemicals. Herein, we designed a simple and cost-effective strategy to enable super-fast yet completed deconstruction of cellulosic aggregates to cellulose molecules via microwave (MW)-assisted-ionic liquid (IL) engineering. MW radiation triggers the high-frequency swing of ions of IL, which leads to superfast heating behavior with a heating rate of ∼20°C/s; meanwhile, the violent rotation of IL ions physically attacks cellulosic aggregates, accelerating their deconstruction. Our MW-IL strategy enables a superfast and complete deconstruction of cellulose (e.g., ∼240 s) compared with the conventional technology (>2400 s with non-complete deconstruction). The deconstructed cellulose can be facilely developed into the intrinsically green, multifunctional gel with high transparent, ion-conductive, injectable and reused advantages, which detects human motions accurately and continuously. The MW-IL-triggered deconstruction of cellulose opens a promising direction for the super-fast, cost-effectively preparation of high-quality cellulose materials, which are versatile toward advanced applications, including flexible electronics, micro/nano fluidics, and energy storage and conversion.
... [8] Moreover, many researches used the MW-induced hot spots as heat source to induce reactions, because the ultra-fast heating rate of MW-absorbing particles under MW irradiation can achieve locally high temperature within minutes. [9] For instance, Huang et al. [10] used MW-induced micro-hot spots to fabricate carbon fiber-supported cobalt nanocatalysts, where the randomly stacked graphene powder in MW field acted as heating source for the pyrolysis of MOF precursors attached on the graphene powder. The carbon materials have strong ability to transform MW energy into Joule heat through the collision of π-electrons and carbon atoms. ...
The hypothesis of microscopic hot spots is widely used to explain the unique microwave (MW) effect in materials science and chemical engineering, but it has not yet been directly measured. Herein we use Eu/Tb mixed‐metal organic complexes as nano thermometers to probe the intrinsic temperature of MW‐absorbing particles in MW fields based on the thermosensitive fluorescent spectra. According to the measurements of the temperature gradient at the solid/liquid interphase, we derive an MW‐irradiated energy transfer model to predict the extent of microscopic hot spots. The fluorescence results agree with the model predictions that the MW‐induced temperature gradient can be enlarged by increasing MW intensity, as well as the dielectric loss and size of particles. Conversely, the increase in the thermal conductivity and the dielectric loss of the liquid lowers the temperature gradient. This study enables control of MW‐assisted synthesis and MW‐responsive techniques.
... [8] Moreover, many researches used the MW-induced hot spots as heat source to induce reactions, because the ultra-fast heating rate of MW-absorbing particles under MW irradiation can achieve locally high temperature within minutes. [9] For instance, Huang et al. [10] used MW-induced micro-hot spots to fabricate carbon fiber-supported cobalt nanocatalysts, where the randomly stacked graphene powder in MW field acted as heating source for the pyrolysis of MOF precursors attached on the graphene powder. The carbon materials have strong ability to transform MW energy into Joule heat through the collision of π-electrons and carbon atoms. ...
The hypothesis of microscopic hot spots is widely used to explain the unique microwave (MW) effect in material science and chemical engineering, but it has not yet been directly measured. The present study uses Eu/Tb mixed metal organic complexes as nano thermometers to probe the intrinsic temperature of MW‐absorbing particles in MW field based on the thermosensitive fluorescent spectra. According to the measurement results of the temperature gradient at the solid/liquid interphase, we derive an MW‐irradiated energy transfer model to predict the extent of microscopic hot spots. The fluorescent experimental results agree with the model predictions that the MW‐induced temperature gradient can be enlarged by increasing MW intensity, as well as the dielectric loss and size of particles. Conversely, the increase in the thermal conductivity and the dielectric loss of liquid weakens the temperature gradient. This fundamental study enables precise control of MW‐assisted synthesis and MW‐responsive techniques.
