SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xinyu Yang,Yueying Zhang,Xidong Hao,Yang Song,Xishuang Liang,Fengmin Liu,Fangmeng Liu,Peng Sun,Yuan Gao,Xu Yan,Geyu Lu
In this paper, an amperometric gas sensor based on proton exchange membrane (Nafion) was fabricated for H 2 S detection at room temperature . Pt-Rh nanoparticles loaded on carbon fibers, as sensing electrode , was prepared by chemical reduction method, and membrane electrode assemble (MEA) was fabricated using hot-pressing method. X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were used to analyze the structure and morphology of the fabricated electrode material. The effect of the weight ratio of Pt to Rh on the performance of the sensor was investigated and the results showed that the sensing performance was best when the ratio of Pt to Rh was 1:1. Moreover, the sensitivity had been significantly improved due to the use of carbon fibers pretreated by nitric acid, increasing from 0.158 μA/ppm to 0.191 μA/ppm. The present sensor could detect H 2 S at levels as low as 0.1 ppm with a −20 nA response and had a good linear relationship in the range of 0.1 to 200 ppm H 2 S. In addition, this amperometric H 2 S sensor displayed fast response-recovery rate as well as excellent selectivity and stability.
研究领域:
材料科学
·
环境监测
·
化学传感器
✓ 已验证
DOI
高影响因子
Nano Energy
·
2016
·
IF 11.553
Lie Yang,Tao Dai,Yuecun Wang,Degang Xie,R. Lakshmi Narayan,Ju Li,Xiaohui Ning
Chestnut-like SnO 2 and SnO 2 /C nanocomposites with hierarchical structures are synthesized by hydrothermally oxidizing Sn nanoparticles in glucose solution. Structural characterizations using SEM and TEM reveal that the SnO 2 nanoparticles are composed of numerous, randomly arranged SnO 2 nanosheets with hollow cores. Owing to the short electron and ion diffusion distances and transformation strain accommodation mechanism of this structure the new SnO 2 /C nanocomposites exhibit enhanced lithium ion storage properties with a capacity of ~930 mAh g −1 and capacity retention of about 96% after 100 cycles at 0.1 C. An in situ TEM study of the electrochemically driven lithiation/delithiation of SnO 2 /C nanocomposites reveals that their enhanced cycling stability is mainly facilitated by the limited volume expansion and excellent mechanical robustness of the hollow chestnuts.
研究领域:
材料科学
·
纳米技术
·
储能
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY A
·
2016
·
IF 2.883
Chunlong Hu,Ying Tang,Xinli Song,Zhiming Liu,Bing Zhang
The photodissociation dynamics of highly excited iodobenzene from the C band absorption has been studied by femtosecond time-resolved ion yields techniques. Detailed photodissociation routes are discussed with the aid of high-level, spin–orbit resolved ab initio calculations of 1D potential energy curves. Upon 200 nm excitation within the C band, iodobenzene molecules on 7B2 and 7B1 states decay to 7A1 and 8B2 states through internal conversion in 75 fs, with electronic energy converted into high vibrational energy of 7A1 and 8B2 states. Subsequently, 7A1 and 8B2 states decay through internal vibrational energy redistribution in 540 fs, accompanied by the excited C–I mode and the resulting cleavage of the C–I bond. The overall time for the reaction starting from the phenyl-type modes and ending in final C–I fragmentation for I(2P3/2) production is 1.2 ps.
研究领域:
物理化学
·
化学动力学
·
光化学
·
超快光谱学
·
量子化学
✓ 已验证
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2026
·Vol. 237
·期 15
·896
·
IF 3.5
Wang Xu,Wang Shaopo,Wang Zhe,Li Yeye,Zhang Rui,Li Rongguang,Chang Jing
ZIF-8-derived materials showed great potential for adsorbing and decomposing ozone, making them suitable for application in catalytic ozonation. This study synthesized four X-Zn-MOF-C (X = 4, 6, 8, 10) materials, among which 10-Zn-MOF-C exhibited the best catalytic performance, possibly due to its superior promotion of ozone decomposition into ∙OH. A probe method was employed to quantify ROS (∙OH, O 2 −· and 1 O 2 ) in the four X-Zn-MOF-C/O 3 systems. The results showed that the yield of ∙OH was lower than that of O 2 −· and 1 O 2 , however, ∙OH played a more critical role in IBP degradation. ROS quenching experiments further confirmed the significant contribution of ∙OH to pollutant removal. Further the investigation into the sources of ∙OH generation was conducted from two dimensions, catalyst sites and solution properties. Compared to the surface hydroxyl protonation of the catalyst, the synergistic effect between the exposed Zn 2+ and oxygen vacancy on the catalyst surface was more favorable for ∙OH generation on the catalyst surface, which mainly resulted from the formations of metal and vacancy hydroxyl groups. Meanwhile, the generation of ∙OH in the solution relied on the contribution of H 2 O 2 produced from pollutant degradation.
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2023
·Vol. 66
·期 5
·2061-2070
·
IF 8.1
Liu Jie,Yang Qing-Qing,Zou Ji,Wang Wei-Min,Wang Xin-Gang,Fu Zheng-Yi
In this study, a type of high-entropy boride (HEB) ceramics ((Ti 0.2 Zr 0.2 Nba 0.2 Hfa 0.2 Taa 0.2 )B 2 ) with ∼2vol% oxides and ∼1 vol% porosity was successfully consolidated by spark plasma sintering at 2000°C under a uniaxial load of 50 MPa for 10 min, using self-synthesized high entropy diboride powders from a boro/carbothermal reduction approach. The residual oxides were determined to be m-(Hf,Zr)O 2 , which were incorporated with minor amounts of boron and carbon. Elastic modulus, Vickers hardness and fracture toughness of HEBs at room temperature were 508.5 GPa, 17.7 ± 0.4 GPa and 4.2 ± 0.2 MPa m 1/2 , respectively. The as-obtained ceramics possessed excellent flexural strength, particularly at high temperatures. The four-point flexural strengths of HEBs at room temperature, 1600, and 1800°C are 400.4 ± 47.0, 695.9 ± 55.9, and 751.6 ± 23.2 MPa, respectively. Postmortem analysis was conducted on HEB fractured at 1800°C, in the region near their tensile and fracture surfaces, and microstructure observations show that limited dislocation lines were present adjacent to the crack front and edge of the pore, without noticing any trace for dislocation motions. It is the first report on the high-temperature strength of high-entropy diboride ceramics and the strengthening mechanism at high temperatures was also discussed.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yongsong Ma,Kaifa Du,Yifan Guo,Mengyi Tang,Huayi Yin,Xuhui Mao,Dihua Wang
Despite the vital roles of Co nanoparticles catalytic oxidation in the Fenton-like system for eliminating pollutants, contributions of Co phases are typically overlooked. Herein, a biphase Co@C core-shell catalyst was synthesized by the electrochemical co-reduction of CaCO 3 and Co 3 O 4 in molten carbonate. Unlike the traditional pyrolysis method that is performed over 700 °C, the electrolysis was deployed at 450 °C, at which biphase structures, i.e., face-centered cubic (FCC) and hexagonal close-packed (HCP) structures, can be obtained. The biphase Co@C shows excellent catalytic oxidation performance of diethyl phthalate (DEP) with a high turnover frequency value (TOF, 28.14 min –1 ) and low catalyst dosage (4 mg L –1 ). Furthermore, density functional theory (DFT) calculations confirm that the synergistic catalytic effect of biphase Co@C is the enhancement for the breaking of the peroxide O–O bond and the charge transfer from catalysts to PMS molecule for the activation. Moreover, the results of radicals quenching experiments and electron paramagnetic resonance (EPR) tests confirm that SO 4 •– , •OH, O 2 •– , and 1 O 2 co-degrade DEP. Remarkably, 100% removals of three model contaminants, including DEP, sulfamethoxazole (SMX) and 2,4-dichlorophen (2,4-DCP), were achieved, either in pure water or actual river water. This paper provides an electrochemical pathway to leverage the phase of catalysts and thereby mediate their catalytic capability for remediating refractory organic contaminants .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2022
·Vol. 9
·期 6
·1952-1960
·
IF 9.473
Jiaqing He,Feng Gao,Haowei Wang,Fangyan Liu,Jiahui Lin,Biao Wang,Chuan Liu,Feng Huang,Zhang Lin,Mengye Wang
H2O2 is an environmentally friendly chemical for wide water treatments and H2 is regarded as an ideal substitute for traditional fossil energy. The industrial production of H2O2 is via the anthraquinone oxidation process, which, however, consumes extensive energy and produces pollution. Herein, based on the density functional theory (DFT) calculations, we report a green and sustainable piezocatalytic intermediate water splitting (IWS) process to simultaneously obtain H2O2 and H2 using C-doped KNbO3 nano single crystals as catalysts. The KNbO3 catalysts doped with suitable amounts of carbon show an enhanced water splitting rate, which could be attributed to the decreased reaction barriers on the C-KNbO3 surface and improved polarized built-in electric field, as evidenced by DFT simulations and PFM measurements. Remarkably, the piezocatalytic H2 evolution efficiency of 0.5 : 1 C-KNbO3 reaches 524.51 μmol g−1 h−1. Additionally, 0.5 : 1 C-KNbO3 could generate H2 and H2O2 simultaneously through two-electron piezocatalytic IWS reactions. This improved catalytic efficiency is attributed to the promoted piezo-response of KNbO3 after C doping, as revealed by PFM tests.
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 8
·2757
·
IF 3.748
Yun Liu,Long Ma,Runa Dong,Kexin Cui,Yongzhao Hou,Wen Yang,Yeqing Liu,Cheng Zhong,Guangwu Wen,Lijuan Zhang
Cf/C-SiC composites have become the preferred material for high-temperature load-bearing applications because of their low density, high strength, and excellent thermal-physical properties. Due to the composite’s poor sintering performance, the sintering temperature and pressure required for the preparation of Cf/C-SiC by traditional methods are also relatively high, which limits its engineering application. Herein, based on the precursor-derived ceramic route and C/C composites material preparation process, a binary binder (coal pitch and polysilylacetylene) is developed, which combines a carbon source, SiC precursor, and semi-ceramic SiC filler organically. Then, the SiC phase was successfully introduced into C/C composites by the slurry impregnation-hot pressing sintering method. The prepared Cf/C-SiC composites showed good mechanical properties, with a density of 1.53 g/cm3and a bending strength of 339 ± 21 MPa. Moreover, the effects of the binary binder on the microstructure, density, and mechanical properties of Cf/C-SiC composites were investigated. This work provides a novel and effective approach to fabricating Cf/C-SiC composites with low density and high strength.Keywords:Cf/C-SiC composite;binary binder;SiC precursor;coal pitch
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 14
·2200333
·
IF 6.389
Xiaoyan Yuan,Huanhuan Li,Aiming Sha,Shengyan Huang,Bo Li,Shouwu Guo
Materials with 1D structure exhibit a remarkable advantage for losing electromagnetic (EM) wave energy. Herein, flexible Mo 2 C-modified SiC/C nanofibers (Mo-SiC/C NFs) are synthesized for the first time by co-electrospinning and subsequent high-temperature pyrolysis, using polycarbosilane (PCS) and molybdenum acetyl acetone (MoO 2 (acac) 2 ) as precursors. It is found that the polymer derived temperature of PCS is significantly decreased by introducing MoO 2 (acac) 2 , as well as endowing the SiC/C NFs with good flexibility, high crystallinity, and remarkable microwave absorption performance. The as-prepared fibers dispersed in paraffin with a low filler loading (15 wt%) exhibit a minimum reflection loss (RL, dB) of -62.5 dB, and a wide effective absorption bandwidth (EAB, RL<-10 dB) of 6.8 GHz at 2.75 mm. Meanwhile, the EAB of the hybrid can cover the whole X-band and most of the C-band by modulating its thickness. These high-efficient performances mainly originate from the specific 1D microstructure, abundant interfaces and defects, and synergistic effect among SiC, Mo 2 C, and C matrix. Thus, this work offers a way to explore flexible SiC/C NFs as a promising candidate with lightweight and wide EAB for EM wave absorption.
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2022
·
IF 16.383
Kang Ma,Tiantong Zhang,Ying Qin,Zhixin Hu,Zhixiang Sun,You Han,Dongbing Zhao,Hong-Ying Gao
Desilylative coupling involving C–Si bond cleavage has emerged as one of the most important synthetic strategies for carbon–carbon/heteroatom bond formation in solution chemistry. However, in on-surface chemistry, C–Si bond cleavage remains a synthetic challenge. Here, we report the implementation of C(sp2)–Si bond cleavage and subsequent C–C bond formation on metal surfaces. The combination of scanning tunneling microscopy and density functional theory calculation successfully reveals that the incorporation of the C–Br group on the arylsilanes is critical to the success of this desilylative coupling reaction on metal surfaces. Our study represents a promising approach for the removal of protecting silyl groups in on-surface chemistry.
✓ 已验证
DOI
PubMed
高影响因子
CARBON
·
2022
·
IF 11.307
Dawei Liu,Lei Yang,Fengyuan Wang,Hao Zhang,Jia Liu,Tong Lv,Hongjie Zhao,Yunchen Du
The construction of special three-dimensional microstructure is becoming an extremely fascinating approach to upgrade the electromagnetic properties of carbon-based microwave absorption materials (MAMs) recently. Herein, we have demonstrated the successful fabrication of a series of carbon nanotubes (CNTs)@Ni/C foams (CNCFs) through two-step pyrolysis processes . It is found that the loading amount of CNTs has an obvious influence on modulating the electromagnetic diameters of CNCFs, and thus effectively tuning their microwave absorption properties . With the relative carbon content of 66.3 wt%, CNCFs-2 exhibits admirable microwave absorption performance , including the effective absorption bandwidth of 5.8 GHz with the absorber thickness of 1.8 mm and the maximum reflection loss intensity of −47.0 dB therein. Electromagnetic analysis reveals that the intrinsic attenuation ability, well-matched characteristic impedance , and multiple reflection effect synergistically work for the excellent reflection loss characteristics of CNCFs-2, which indicates rational microstructure design and appropriate chemical composition regulation are vitally important for the enhancement of microwave absorption performance. We believe these desirable microwave absorption properties can make CNCFs-2 eligible to be a very promising candidate for high-performance MAMs, and this research will provide some inspirations more or less for the development of more advanced carbon-based MAMs in the future.
✓ 已验证
产品关联
DOI
高影响因子
Cell and Bioscience
·
2022
·Vol. 12
·期 1
·1-20
·
IF 9.584
Zhang Yufeng,Yang Min,Zhang Sheng,Yang Zhiqiang,Zhu Yufan,Wang Yi,Chen Zhe,Lv Xuan,Huang Zan,Xie Yuanlong,Cai Lin
Background Dysregulated osteoclast activity due to altered osteoclast differentiation causes multiple bone diseases. Osteoclasts are multinucleated giant cells derived from hematopoietic stem cells and play a major role in bone absorption. However, the mechanisms underlying the tight regulation of osteoclast differentiation in multiple pathophysiological status remain unknown. Results We showed that Bhlhe40 upregulation is tightly associated with osteoclast differentiation and osteoporosis. Functionally, Bhlhe40 promoted osteoclast differentiation in vitro, and Bhlhe40 deficiency led to increased bone mass and decreased osteoclast differentiation in vivo. Moreover, Bhlhe40 deficient mice resisted estrogen deficiency and aging-induced osteoporosis. Mechanism study showed that the increase in bone mass due to Bhlhe40 deficiency was a cell intrinsic defect in osteoclast differentiation in these mice. BHLHE40 upregulated the gene expression of Fos and Nfatc1 by directly binding to their promoter regions. Notably, inhibition of Fos/Nfatc1 abrogated the enhanced osteoclast differentiation induced by BHLHE40 overexpression. Conclusions Our research reveals a novel Bhlhe40/c-Fos/Nfatc1 axis involved in regulating osteoclastogenesis and shows that osteoporosis caused by estrogen deficiency and aging can be rescued by regulating Bhlhe40 in mice. This may help in the development of a new strategy for the treatment of osteoporosis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）