CRYSTENGCOMM
·
2022
·Vol. 24
·期 26
·4772-4786
·
IF 3.756
Zhixin Ma,Yang Qi,Xiaoguo Bi,Xu-dong Liu,Xiaodong Li,Ji-guang Li,Xudong Sun
SrTiO3 has high thermoelectric properties and excellent high-temperature stability, which makes it a promising thermoelectric material for use in harsh environments. Hence, it has potential applications in power generation and sensors through direct conversion between heat and electricity. In this study, we investigated the crystal orientations on the crystal growth plane to seek the crystal orientation that is suitable for higher thermoelectric (TE) properties. The [510], [12 5 0] and [320] directions were selected which are on the (001) crystal plane and quarterly divide the angle between the [100] and [110] directions. Two common directions [100] and [110] were selected for comparison purposes. The SrTiO3 single crystals are annealed in carbon powders at 1573 K and 1673 K to form SrTiO3−δ. With the increase in annealing temperature, the electrical conductivity of SrTiO3−δ in the [510], [12 5 0] and [320] directions decreases, which is attributed to the decreasing carrier concentrations. This agrees well with the results calculated using the first-principles calculation. After annealing at 1573 K, the SrTiO3−δ single crystal exhibits the highest ZT value of 0.19 at 873 K in the [510] direction. However, the two common directions, [100] and [110], are not suitable for high thermoelectric properties. In particular, the SrTiO3−δ single crystal in the [12 5 0] direction can always exhibit higher PF and ZT values, regardless of the variation of the annealing temperature in carbon powders. The results of this study are imperative for the design and development of perovskite TE materials.
研究领域:
材料科学
·
热电材料
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 16
·3862
·
IF 4.2
Guangyue Shi,Xiaolei Sun,Yao Liu
Percolating composites exhibiting negative permittivity have garnered considerable attention due to their promising applications in the realm of electromagnetic shielding, innovative capacitance devices, coil-less inductors, etc. Nano carbon powder/polyvinylidene fluoride (CP/PVDF) percolating composites were fabricated that exhibit Drude-type negative-permittivity behavior upon reaching the CP percolation threshold. This phenomenon is attributed to the formation of a plasmonic state within the interconnected CP network, enabling the delocalization of electrons under the alternating electric field. Furthermore, a significant (nearly two orders of magnitude) increase in the conductivity of sample is observed at a CP content of 12.5 wt%. This abrupt change coincides with the percolation phenomenon, suggesting a transition in the conduction mechanism. To elucidate this behavior, comprehensive analyses of the phase composition, microstructure, AC conductivity, and relative permittivity were performed. Additionally, the sample containing 5 wt% CP exhibits a remarkably high permittivity of 31.5, accompanied by a relatively low dielectric loss (tanδ < 0.2). The findings expand the potential applications of PVDF, while the fabricated percolating composites hold promise for electromagnetic shielding, antennas, and other electromagnetic devices.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Junlin Xie,Kun Wei,Xiaoqing Liu,De Fang
Carbon powders were used to detoxify [Cr(VI)] in metallurgical solid waste was investigated, since the presence of [Cr(VI)] had a very serious impact on the environment. Five types of carbon powders were selected as carbon sources and soluble CrO 3 was used as a hexavalent chromium source in metallurgical solid waste. Ultra-fine Cr 3 C 2 powders (about 80 nm) were synthesized by carbothermal reduction reaction to achieve the detoxification of [Cr(VI)]. The temperature plays a crucial role in the synthesis of Cr 3 C 2 according the experimental and thermodynamic results, illustrating that the synthesis temperature was in the range of 900 ℃–1200 ℃. Surface area, morphology, and surface chemistry of carbon powders were investigated to analyze the effect of carbon type on the mechanism of detoxification of hexavalent chromium [Cr(VI)] and the formation of chromium carbide . The results show that nano carbon powder with finer particle size (30–50 nm), higher specific surface area (101.5 m 2 /g) and fewer chemical bonds with carbon atoms formed by sp 2 orbital hybridization are more suitable as a carbon source for carbothermal reduction of [Cr(VI)]. Therefore, nano Cr 3 C 2 powder was achieved at the lowest synthesis temperature (900 ℃), when nano carbon powder was selected as the carbon source.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2021
·Vol. 24
·期 3
·1335-1341
·
IF 10.182
Wenyan Zhang,Hangmin Guan,Yingfei Hu,Wei Wang,Linyun Hao,Xiaoli Yang,Wenjie Tian
With the dramatic increase in the application of modern office equipment, such as laser printers and photocopiers, large amounts of waste toner powder are used and discarded, ending up in landfills around the world. As waste toner powder contains hazardous compounds that can seriously endanger both the environment and human health, it is urgent to deal with waste toner powder and convert it into high value-added products. In this work, we report, for the first time, visible-light-driven hydrogen production with waste toner activated by cheap Ni species (waste toner@Ni-species) as the photocatalyst. The Ni species adhered to the waste toner through in situ photoreduction, without sophisticated equipment. It is found that the Ni species were composed of metallic Ni and oxidized Ni, which worked in synergy to remarkably enhance the photocatalytic activity of the waste toner. Activated by the Ni species, the hydrogen evolution rate of the waste toner was accelerated by up to 62 times, and the apparent quantum efficiencies (AQEs) of the waste toner were boosted by up to 64 times. In addition, the waste toner@Ni-species exhibited a higher charge separation efficiency, faster interfacial charge transfer rate and ∼200 mV lower barrier for proton reduction than those of the pristine waste toner. In addition to these merits, the waste toner@Ni-species could be separated conveniently from the aqueous system using magnetic attraction, as the saturation magnetization and residual magnetism of the waste toner were improved with the assembly of the Ni species. The approach shown here indicates a simple and promising way to deal with waste toner by converting it to a cost-effective photocatalyst for producing clean energy.
研究领域:
环境科学
·
能源材料
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Weicong Li,Narayanamoorthy Bhuvanendran,Huiyuan Liu,Weiqi Zhang,Khadijeh Hooshyari,Sae Youn Lee,Qian Xu,Huaneng Su
Platinum-group-metal-based polyhedral nanostructures generally possess high catalytic activity for electrochemical reactions owing to their numerous edges, corners, and well-defined lattice planes . However, their direct synthesis on common carbon powder is difficult, which considerably hinders their applications in practical devices. Herein, we report PtPd nanocubes (NCs) grown in situ on commercial carbon powder (Vulcan XC-72R) using a facile one-pot method. The as-prepared PtPd NCs/C (∼20 wt% metal) possess Pt-enriched surfaces, enabling the mass activity (MA) of methanol oxidation reaction (MOR) up to 1.77 A mgPt −1 , which is 3.34/3.69 times that of commercial PtRu/C and Pt/C, respectively. With an average size of 8–10 nm, the PtPd NCs/C exhibit high stability, retaining over 80% initial MA against MOR in an accelerated durability test. For practical direct-methanol fuel cell (DMFC) operation, the PtPd NC/C as an anode catalyst delivered a maximum power density of 0.232 W cm −2 with high-concentration methanol (10 M) flow, which is 1.6 times higher than that for commercial PtRu/C under the same conditions. Moreover, the PtPd NCs/C demonstrated excellent durability for DMFC operation with much lower voltage decay than commercial PtRu/C, indicating its excellent potential for practical DMFC applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Iranian Chemical Society
·
2022
·Vol. 19
·期 6
·2543-2551
·
IF 2.271
Ge Dandan,Zhang Yi,Deng Xiujun,Yuan Lin
In this study, a zinc-based MOF material-[Zn 2 (btc)(atrz)(H 2 O) 2 ]·2H 2 O (btc = benzene-1,2,4-tricarboxylic acid, artz = 4-amino-1,2,4-triazole) was designed and applied as a sorbent for the vortex-assisted micro-solid-phase extraction (VA-µ-SPE) of UV filters from water and toner samples, followed by high performance liquid chromatography-diode array detector determination. Parameters affecting VA-µ-SPE such as sorbent amount, desorption solvent, vortex time, desorption time, solution pH and salt concentration were optimized. Under the optimized conditions, linearity of the UV filters was obtained in the range of 5(10)–1000 ng mL −1 , and the correlation coefficient was higher than 0.9959. The limits of detection ranged between 1.5 and 3.2 ng mL −1 and limits of quantification were in the range of 4.2–10 ng mL −1 . The relative standard deviations were in the range of 2.3–7.1%. The recoveries for the spiked real samples were in the range of 90.7–111.3% with relative standard deviation less than 7.2%. It proved to be a fast, accurate and convenient method for extraction of UV filters from different matrices.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Qiuyu Mei,Cailin Yang,Tingting Mao,Haipu Li,Zhian Wang,Hua Wan,Kai Han
Superseded toner cartridges in printers often contain abundant residual toner during the replacement. These toners contain resins, Fe3O4, and SiO2 particles. Waste toner disposal results in resource wastage and solid waste accumulation. Thus, several methods have been proposed for the high-value-added conversion of waste toners. However, the photothermal conversion ability of toners and its application in solar-driven interfacial evaporation have not yet been explored. Herein, waste toner was recycled via high-temperature calcination and acid etching, which yielded two novel photothermal materials, namely HTC-T and HA-T. The light absorption capacity of HA-T reached 96.84%, and the evaporation rates of methanol, ethanol, isopropanol, water, N,N-dimethylformamide, and N-methyl pyrrolidone under 1 sun irradiation of HA-T membranes were 6.07, 5.95, 6.71, 2.15, 3.74, and 1.49 kg·m–2·h–1, respectively. Moreover, HCT-T and HA-T were able to degrade up to 99.99% of methyl orange, methylene blue, and rhodamine B solutions at a concentration of 20 ppm. This study thus provided a recovery technique for waste toner that realized the recycling of solid waste resources with environmental and economic benefits.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Hao Xiong,Anze Shui,Qingliang Shan,Shenghui Zeng,Xiuan Xi,Bin Du
Polishing porcelain stoneware tile residues (PPR) is used to prepare foamed ceramic to solve the problem of solid waste discharge in ceramic industry. In this study, C, Al and Si powder were added to the simulated PPR to control foaming, and the mechanism of silicon carbide foaming in the PPR was discussed in detail. After these powders were introduced into the simulated PPR, the phenomenon of alumina crystallization on the pore wall of the foamed ceramic and the diffusion of gas in the foamed ceramic were discovered to be exciting. The foaming mechanism of PPR is detailed as follows: the diffusion rate of oxygen in silicate liquid is faster than that of CO during sintering, so the CO generated by incomplete oxidation of silicon carbide in PPR accumulates in the liquid, which makes the volume of ceramics expand and causes foaming.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-7
·
IF 5.479
Xu Qiang,Gong Yan,Zhang Zhifeng,Miao Yanming,Li Dongxia,Yan Guiqin
A one-pot hydrothermal method was developed for the synthesis of graphene oxide quantum dots (GOQDs). It is making use of toner waste as the precursor and H 2 O 2 as the oxidant. Synthesis takes 4 h and does not require strong acids or complex purification steps and does not produce environmentally harmful metal ions. The GOQDs display blue fluorescence with excitation/emission maxima at 340/445 nm. The feasibility of detecting specific DNA sequence was promoted using polyethyleneimine to modify the GOQDs surface. A method was developed to recognized a specific DNA sequence. This is based on electrostatic aggregation of GOQDs and ssDNA labeled with Dabcyl at the 3′ end, which promotes fluorescence quenching of GOQDs. The possible fluorescence quenching mechanism (which is mainly dynamic) was investigated using the Stern-Volmer equation. When a target sequence was added, which is complementary to the ssDNA, the dabcyl-labeled ssDNA is released due to strict complementary base pairing. This promotes fluorescence recovery of GOQDs. The assay has a 0.17 nM detection limit and a linear range of 0.5–30 nM. The method was used to quantify specific DNA sequences from extracts of genetically modified plant tissues.
Graphene oxide quantum dots (GOQDs) were synthesized by one-pot hydrothermal method using waste toner, and the surface was modified by polyethyleneimine (PEI). Through the interaction of PEI-GOQDs with Dabcyl-DNA single strands to dynamically quench the fluorescence of GOQDs. Based on DNA hybridization technology, we established specific DNA sequence detection nanoprobe.
研究领域:
生物化学
·
环境科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2023
·Vol. 13
·期 1
·1-12
·
IF 4.6
Liu Yanhua,Liu Xingfei,Chen Juanning,Zhang Zhuanli,Feng Libang
Laserjet printing is a kind of facile and digital do-it-yourself strategies, which is of importance to fabricate inexpensive paper-based microfluidic devices. However, the printed hydrophobic barrier is not hydrophobic enough due to the weak hydrophobicity and requires subsequent heating, which can lead to the pyrolysis of cellulose in the paper and influence the detection results. Here, for the first time, we report a kind of functional toner including toner and polydopamine (PDA) nanocapsules which contains oleic acid modified ferric tetroxide (OA-Fe 3 O 4 ) and octadecylamine (ODA), which is suitable for printing with desired shapes and sizes to lead to formation of superhydrophobic barriers. Moreover, patterns printed with functional toner have good stability, including resistance to moisture, ultraviolet (UV) and bending. Finally, a proof-of-concept of metal and nitrite ions testing is demonstrated using colorimetric analysis, and the results show that the printed devices successfully perform instant detection of ions. The developed functional toner offers easy fabrication, cost-effectiveness and mass production of paper-based devices. In general, this strategy provides a new idea and technical support for the rapid prototyping of microfluidic paper-based analytical devices (μPADs) using laserjet printing.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 13
·18876-18883
·
IF 5.532
Zhixin Ma,Yang Qi,Jun Wang,Xiaoguo Bi,Xu-dong Liu,Xiaodong Li,Ji-guang Li,Xudong Sun
SrTiO 3 is a promising thermoelectric material for applications in harsh environments, owing to its excellent thermoelectric (TE) properties and high-temperature stability. The effect of annealing in carbon powders on the TE properties of SrTiO 3−δ in the [111] direction was experimentally investigated and analysed using first-principles calculation. The electrical conductivity of the SrTiO 3−δ single crystals in the [111] direction increases with an increase in annealing temperature in the range of 1573–1673 K, which is opposite to that in the [510] direction as shown in a previous experiment. This is attributed to the different variation trend of carrier concentration. First-principle calculation results show that the carrier concentration in the [111] direction increases with increasing oxygen vacancy concentration, but it is the opposite in the [510] direction. Strong anisotropy of carrier concentration should be caused by the difference in atomic arrangement, making difference in the amount of free electrons that maybe constrained at high oxygen vacancy in different directions. Although the SrTiO 3−δ single crystal annealed at 1573 K shows a lower electrical conductivity, it obtains higher power factor with the maximum value of 2.24 mW m −1 K −2 at 323 K, which is predominantly due to its higher effective mass. It also yields the highest ZT value of 0.18 at 873 K owing to the lower thermal conductivity . The results of this study are imperative for the design and development of perovskite TE materials.
研究领域:
材料科学
·
凝聚态物理
·
热电材料
·
晶体学
·
固体化学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2023
·
IF 2.1
Xin Yue,Jinsheng Zhao
In this work, two D-A monomers 2,3-di(5-methylfuran-2-yl)-5,7-di(thiophene-2-yl) thiopheno[3,4-b] pyrazine (MFTTP) and 2,3-di(5-methylfuran-2-yl)-5,7-di(4-methoxythiophen-2-yl) thiopheno [3,4-b] pyrazine (MFMOTTP) were first obtained by Stille Coupling reaction, and then the corresponding composites were obtained by in-situ oxidative polymerization method with supercapacitor carbon. The surface morphology, chemical structure, and the element valence states of two materials were characterized by scanning electron microscopy, infrared and XPS, respectively. The specific surface areas of PMFTTP@SC and PMFMOTTP@SC are measured as 756.5 and 954.9 m2/g, respectively. The CV curves were used to determine the initial oxidative and initial reduction potentials, both polymers have a narrow band gap with Eg values below 1.5 eV, electron clouds in the HOMO and LUMO orbits of the polymer are mainly distributed on the aromatic rings of the polymer backbone. Polymer composite materials were used as the anode materials and the lithium sheets were used as counter electrode, and then lithium ion batteries are assembled. The first discharge specific capacities of PMFTTP@SC and PMFMOTTP@SC are 741.9 and 951.3 mAh/g at a current density of 100 mA/g, and as the electrodes are activated in the subsequent cycles, their coulomb efficiencies can reach more than 92% from the third cycle. In contrast, PMFMOTTP with methoxy-thiophene as the donor unit has higher conductivity and lower corresponding impedance due to its stronger electron donating ability and abundant pore structure, which is also more conducive to the lithiation/delithiation redox process.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）