INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Sen Xiong,Yang Yang,Zhaoxiang Zhong,Yong Wang
Reusable absorbents with high absorption capacity, good selectivity, and low cost are highly demanded for efficient removal of oil spills and organic leakages from water. We discover that ZnO produced by atomic layer deposition (ALD) is hybridized with carbon moieties, and consequently exhibits an appreciable hydrophobicity. By taking this advantage, we develop a “dry” process to produce high-performance oil absorbents. Originally amphiphilic polymeric foams are directly turned into strongly hydrophobic oil absorbents simply by ALD of ZnO and exhibit excellent absorption capacity, selectivity and reusability. Such absorption capacities and reusability are better than most foam-based oil absorbents. Surprisingly, we find that ALD-deposited ZnO can reverse the wettability of polymeric foams depending on the foam porosities. This ALD-enabled surface functionalization is expected to find important applications in the synthesis of many other interfacial materials.
研究领域:
材料科学
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环境工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Yu Zhang,Hao-Bin Zhang,Xinyu Wu,Zhiming Deng,Ergang Zhou,Zhong-Zhen Yu
High-performance broadband microwave absorbers are greatly required to cope with the increasingly serious microwave radiation pollution. Integration of dielectric and magnetic components is a promising strategy to achieve desirable microwave absorption performance. Herein, we demonstrated a facile and efficient approach to fabricate two-dimensional cobalt@carbon (Co@C) hybrids by solvothermal synthesis of cobalt–metal–organic framework (Co-MOF) nanosheets and subsequent thermal pyrolysis for efficient microwave absorption application. The resultant nanolayered Co@C hybrids inherit the two-dimensional architecture of the Co-MOF nanosheets. During the thermal pyrolysis of Co-MOF, its organic component is carbonized to amorphous carbon while its cobalt ions are carbothermally reduced to cobalt nanoparticles, thus in situ integrating the magnetic metal nanocrystal with the dielectric carbon. Consequently, a wide effective absorption bandwidth of 5.44 GHz at a small thickness of 1.76 mm and a minimum reflection loss value of −49.76 dB are achieved for the wax composite with 30 wt % of Co@C hybrid pyrolyzed at 800 °C. The outstanding microwave absorption performances are attributed to the synergistic effects of the Co@C hybrid nanosheets and their large shape anisotropy, which facilitates the strong dielectric loss and good impedance matching, thus promising the nanolayered Co@C hybrid as a lightweight and high-performance microwave absorber.
研究领域:
材料科学
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电磁学
·
纳米技术
✓ 已验证
DOI
CARBON
·
2025
·
IF 11.6
Shijie Zhang,Jiajun Zheng,Changpeng Lv,Di Lan,Qingfeng Tian,Zhenguo Gao,Siyuan Zhang,Zhiwei Zhao,Shichang Cai,Guanglei Wu
The incorporation of a built-in electric field (BIEF) in nanocomposites has been well-recognized as a mainstream approach for enhancing the interface polarization. Nevertheless, the effect of sole BIEF on the dielectric loss is insufficient, and its combination with other loss mechanisms is necessary to achieve optimized electromagnetic wave performances. Herein, the nano carbon hybrids with Cu–ZnO Schottky BIEF with abundant defects were designed and derived through an etching and ligand exchange process, which involved the conversion of CuZn-BTC into a bimetallic ZIF structure. The conversion process effectively controlled the morphologies and induced a significant density of defects in the derivatives, thereby imparting diverse electrical conductivities and dielectric properties to the composites. This was achieved through the modulation of the cell volumes of Cu–ZnO polycrystals, the oxygen vacancies in ZnO, the nitrogen defects within the carbon matrix, and the creation of extensive heterointerfaces. The analysis indicated that the polarization relaxation dominated the dielectric loss. When the H 2 O/methanol in etching solvent was 3:7, the derived composite (S2) exhibited well matched impedance, and synergistic enhancement of BIEF effect and defect-induced polarization. Attributed to these merits, S2 achieved an ultra-wide effective absorption bandwidth (EAB) of 7.12 GHz at 2.3 mm. Notably, the EAB exceeded 6.0 GHz when the matched thickness ranged from 1.8 mm to 2.7 mm. This study can introduce a novel approach for the development of advanced absorbers based on the Schottky BIEF.
研究领域:
材料科学
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电磁学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 29
·14345-14357
·
IF 3.553
Li Qingsong,Liu Qiangchun,Kong Xiangkai
Abstract Metal-free hybrids possess many advantages when compared with metal-based materials, such as lightweight, low cost, and high stability, which offer great potential for them to be used in wide applications, such as microwave absorption. Bare carbon materials, especially for those derived from wasted biomass, normally cannot simultaneously exhibit strong and broadband absorption performance, due to their specific structures and high electronic conductivity, leading to more incident microwave reflected on surface. Herein, based on wasted grapefruit peels, 2D metal-free hybrids are designed and prepared with pre-exfoliated boron nanoflakes as the modulation. Noncovalent interaction is formed at their heterojunction, which endows them with properties that cannot be supplied by their individual components. As a result, interfacial polarizations and dipole polarizations are generated between the layers, benefiting the dielectric loss and impedance matching behaviors. Microwave absorption measurements demonstrate that the minimum reflection loss can reach − 47.9 dB and the effective absorption frequency band is 4.32 GHz, at 1.5 mm thickness. We hope these represent an addition to the family of sustainable biomass-derived microwave absorbents. Graphic abstract
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Small Methods
·
2020
·Vol. 4
·期 9
·2000208
·
IF 12.13
Chaoxiong Zhang,Haoxuan Liu,Yifan Liu,Xijun Liu,Yuying Mi,Ruijie Guo,Jiaqiang Sun,Haihong Bao,Jia He,Yuan Qiu,Junqiang Ren,Xiangjun Yang,Jun Luo,Guangzhi Hu
Using hydrazine oxidation reaction (HzOR) to replace the oxygen evolution reaction is an effective way to decrease the overpotential of the anodic reaction in overall water splitting (OWS), facilitating cost-effective and safe hydrogen production. Herein, Rh 2 S 3 /N-doped carbon hybrids (Rh 2 S 3 /NC) are first reported as novel and efficient bifunctional electrocatalysts for hydrazine-assisted hydrogen generation over a wide pH range. Specifically, Rh 2 S 3 /NC exhibits low overpotentials for the hydrogen evolution reaction (HER) in alkaline (38 mV), neutral (46 mV), and acidic (21 mV) electrolytes, to reach the current density of 10 mA cm −2 , and maintains the activities over 70 h. Meanwhile, Rh 2 S 3 /NC also displays competitive HzOR performance at all-pH electrolytes. Thus, serving as a bifunctional electrocatalyst for both HER and HzOR, Rh 2 S 3 /NC shows overwhelming-Pt/C performance in three electrolytes, and can save over 93.3%, 85.2%, and 78.3% energy consumption compared to the corresponding OWS system. Moreover, theoretical calculations confirm that Rh 2 S 3 /NC owns low free-energy changes of the H adsorption and the dehydrogenation of adsorbed NHNH both of which are beneficial to enhance catalytic activity. This work develops a novel bifunctional electrocatalyst with free pH-dependent condition for the hydrazine-assisted electrolysis system to furtherly reduce the cost of massive industrial H 2 production.
研究领域:
材料科学
·
能源化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2015
·
IF 6.196
Qing Lv,Kui Li,Changpeng Liu,Junjie Ge,Wei Xing
Commercially available carbon black is a widely applied support material for nanocatalysts but notorious for its microporous structure, which is deleterious for catalysts utilization in the fuel cell application and causes numerable problems in other application areas. The development of mesoporous carbon as a substitute was proved successful but not scalable due to their intrinsic complex synthesis. In this work, we demonstrate a new perspective to circumvent the problem through blocking the micropores of carbon black by the in-situ formed TiO 2 nano/sub-nano particles. A decompression absorption method was developed where tetrabutyl titanate was pressurized into carbon pores with diameter <3 nm, succeeded by hydrolysis and calcination to form the TiO 2 inserted commercial carbon black, such as BP2000 and Vulcan XC-72. The TiO 2 –C hybrid material with reduced micropore volume was found an excellent support for noble catalysts, such as Pt and Pd nanoparticles, where their insertion into carbon micropores during synthesis were prevented, thus leading to improved metal utilization. The TiO 2 –C supported catalysts exhibited much superior activity and stability for methanol or formic acid electrooxidation in comparison to the plain carbon black. This work also demonstrated the negative effects of micropores in carbon support.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xiaoqian Dai,Huitian Liu,Xu Liu,Zhaolin Liu,Yuansheng Liu,Yuhao Cao,Junyan Tao,Zhongqiang Shan
The application of silicon as anode materials for lithium-ion batteries is limited by the huge volumetric expansion and complex synthesis processes. Herein, silicon nanoparticles encapsulated in multifunctional crosslinked nano-silica/carbon hybrid matrix (Si@n-SiO 2 /C) composites are successfully synthesized via simultaneous condensation copolymerization between (3-aminopropyl)-triethoxysilane (APTES) and L-ascorbic acid (L-AA). With the introduction of nano-silica, the multifunctional nano-silica/carbon hybrid matrix can significantly maintain structural integrity during the volume change of silicon, provide a higher capacity than the traditional single carbon coating layer and enhance the conductivity of the materials. Correspondingly, the obtained Si-2@n-SiO 2 /C composites display quite outstanding cycle stability and superior structural integrity maintenance, which delivers a capacity of 800.7 mAh g −1 after 300 cycles at the current density of 1 A g −1 . Such a novel coating layer structure design and simultaneous growth of nano-silica/carbon hybrid matrix layer on silicon nanoparticles will provide a simple synthesis strategy for manufacturing high-performance Si-based anode materials.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2024
·Vol. 67
·期 3
·788-795
·
IF 6.8
Song Dewen,Zhang Shipeng,Ning Hui,Fei Xiang,Wang Mingwang,Wang Xiaoshan,Wu Wenting,Zhao Qingshan,Li Yongzhe,Wu Mingbo
CO 2 electroreduction is an alluring technology for high-value CO 2 utilization and intermittent electrical energy storage. Self-supporting catalysts with high efficiency have clear advantages over powder ones in electrode construction but still lack effective synthesis methods. In this work, a self-supporting BiCu/carbon hybrid nanofiber membrane (BiCu/CHNM) was synthesized by electrospinning-calcination and employed directly as a working electrode in a flow cell for CO 2 electroreduction to formate with a high Faradaic efficiency of 87.67% at a partial current density of 142.9 mA cm −2 . In stability tests, the Faradaic efficiency of formate remained at 80% for 50 h at high partial current densities (>100 mA cm −2 ). In-situ Raman spectra and density functional theory calculations confirmed that copper doping lowers the energy barrier of HCOO − formation on the Bi (012) plane and increases the conductivity of the carbon nanofiber network. Due to the well-designed conductive framework and the highly dispersed BiCu active sites, this hybrid membrane shows high activity, high selectivity, and long stability simultaneously.
研究领域:
电化学
·
纳米材料
·
能量转换
·
环境技术
·
材料科学
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 38
·2302831
·
IF 13.3
Tianhao Yao,Hongkang Wang,Xin Ji,Deyu Wang,Qingmiao Zhang,Lingjie Meng,Jian-Wen Shi,Xiaogang Han,Yonghong Cheng
Titanium dioxide (TiO 2 ) is a promising anode material for sodium–ion batteries (SIBs), which suffer from the intrinsic sluggish ion transferability and poor conductivity. To overcome these drawbacks, a facile strategy is developed to synergistically engineer the lattice defects (i.e., heteroatom doping and oxygen vacancy generation) and the fine microstructure (i.e., carbon hybridization and porous structure) of TiO 2 -based anode, which efficiently enhances the sodium storage performance. Herein, it is successfully realized that the Si-doping into the MIL-125 metal-organic framework structure, which can be easily converted to SiO 2 /TiO 2–x @C nanotablets by annealing under inert atmosphere. After NaOH etching SiO 2 /TiO 2–x @C which contains unbonded SiO 2 and chemically bonded Si O Ti, thus the lattice Si-doped TiO 2–x @C (Si-TiO 2–x @C) nanotablets with rich Ti 3+ /oxygen vacancies and abundant inner pores are developed. When examined as an anode for SIB, the Si-TiO 2–x @C exhibits a high sodium storage capacity (285 mAh g −1 at 0.2 A g −1 ), excellent long-term cycling, and high-rate performances (190 mAh g −1 at 2 A g −1 after 2500 cycles with 95.1% capacity retention). Theoretical calculations indicate that the rich Ti 3+ /oxygen vacancies and Si-doping synergistically contribute to a narrowed bandgap and lower sodiation barrier, which thus lead to fast electron/ion transfer coefficients and the predominant pseudocapacitive sodium storage behavior.
研究领域:
材料科学
·
能量存储
·
纳米技术
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）