THERMOCHIMICA ACTA
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2018
·
IF 2.189
Feng Bao,Lishuai Zong,Nan Li,Yuanyuan Song,Yunxing Pan,Jinyan Wang,Xigao Jian
In this study, a series of poly(phthalazinone fluorenyl ether ketone ketone) (PPFEKK) copolymers were designed and synthesized via nucleophilic aromatic substitution polymerization of 1,4-bis(4-fluorobenzoyl)benzene (BFBB), 4-(4-hydroxyphenyl)(2 H)-phthalazin-1-one (DHPZ) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) to investigate the effects of bulky fluorene units on the processability and thermal degradation behavior of the polymers. The structures of the PPFEKKs were investigated and confirmed by FTIR, 1 H NMR, wide-angle X-ray diffraction (WAXD) and gel permeation chromatography (GPC) techniques. Traditional thermal measurements showed that the T d 5% and T d 10% values of the copolymers increased as the content of BHPF units increased from 0 to 100 mol%, while their glass transition temperatures gradually decreased. The rheological measurements showed that the processability of the copolymers significantly improved upon incorporation of BHPF units; the poly(aryl ether)s were less viscous and thus more processable. The thermal degradation kinetics were clarified using TGA with Kissinger’s method. The copolymer undergoes two thermal degradation processes: as the content of BHPF units in the copolymers increased from 0 to 100 mol%, the activation energy of the first degradation reaction increased from 228 to 254 kJ mol −1 , and the activation energy of the second degradation reaction increased from 271 to 298 kJ mol −1 . The resulting films displayed excellent tensile strength (higher than 76 MPa), and their Young’s modulus values were inversely proportional to their BHPF contents. Dynamic mechanical analysis showed storage modulus values at 30 °C of approximately 2662, 2826, 2698, 2791 and 2830 MPa for the prepared polymers. Furthermore, the PPFEKKs were soluble in a variety of organic solvents, making them suitable for film casting.
研究领域:
高分子化学
·
材料科学
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Dafeng Zhang,Dong Zhang,Shikai Wang,Hengshuai Li,Junchang Liu,Xipeng Pu,Peixian Chen,Ran Qin,Haiquan Hu,Peiqing Cai
Suppressing the electron-hole recombination rate of catalyst legitimately is one of the effective strategies to improve photocatalytic hydrogen evolution . Herein, carbon-coated metal oxide , ZnFe 2 O 4 @C (ZFO@C), nanoparticles were synthesized and employed to couple with quadrupedal Cd 0.9 Zn 0.1 S (CZS) via an ordinary ultrasonic self-assembly method combined with calcination to form a novel ZFO@C/CZS catalyst with step-scheme (S-scheme) heterojunction . The photocatalytic hydrogen evolution reaction (HER) was conducted to verify the enhanced photoactivity of ZFO@C/CZS. The optimal ZFO@C/CZS exhibits an extraordinary photocatalytic HER rate of 111.3 ± 0.9 mmol g -1 h −1 under visible-light irradiation, corresponding to an apparent quantum efficiency as high as (76.2 ± 0.9)% at 450 nm. Additionally, the as-synthesized ZFO@C/CZS composite exhibits high stability and recyclability. The excellent photocatalytic hydrogen evolution performance should arise from the formed S-scheme heterojunction and the unique ZFO@C core–shell structure, which inhibit electron hole recombination as well as provide more reactive sites. The pathway of S-scheme charge transfer was validated through density functional theory calculations and electrochemical measurements. This work provides a rational strategy for the synthesis of unique magnetic S-scheme heterojunction photocatalysts for water splitting under visible light irradiation.
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Small Science
·
2023
·Vol. 3
·期 12
·2300134
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IF 12.7
Xiaomeng Shi,Zhichao Zeng,Yongqing Wen,Hongtu Zhang,Yabin Zhang,Yaping Du
All-solid-state lithium batteries (ASSLBs) are a research hotspot for their superior safety. The solid electrolytes (SEs) are key components in ASSLBs, and the emerging rare-earth halide SEs (RE-HSEs) are valued for their comprehensive performances of good ionic conductivity, electrochemical stability, and deformability. In addition, cathode materials can influence the properties of ASSLBs, and sulfur (S) attracts much attention due to the lower toxicity and much higher energy density compared with commercial oxide cathodes. However, the S possesses poor electronic conductivity, which can be improved by the introduction of selenium (Se) with much higher electronic conductivity. In this work, a series of Se x S 1– x composites is synthesized by a melting method. Due to the introduction of Se and the enriched defects from the melting process, the electronic and ionic conductivities of Se x S 1– x are improved. After application in ASSLBs based on RE-HSE Li 3 YBr 6 , the Se x S 1– x materials exhibit good performances with low polarizations, good cycling stabilities, and excellent rate properties at room temperature. Moreover, the assembled solid batteries can realize stable cycling performance (100 cycles) at low temperature (−30 °C) and a normal discharge–charge process at high temperature (120 °C).
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PROGRESS IN ORGANIC COATINGS
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2023
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IF 6.6
Yufa Sun,Hao Xin,Yi Wu,Chen Zhang,Changjie Chen,Xiangdong Zhou
A new type of flame-retardant polyether diols containing phosphorus, nitrogen, and sulfur (SPAE) was first synthesized by using phosphoryl chloride, 2-aminobenzothiazole and ethylene glycol . The SPAE as the soft segment was then utilized to prepare a series of flame-retardant waterborne polyurethanes (SPAE-WPU) through emulsion polymerization . Subsequently, SFR-WPU as a finishing agent was coated on polyamide fabric. When the content of SPAE-WPU was 18 wt%, the coated fabric exhibited a limiting oxygen index (LOI) of 28.2 %, afterflame time of 4.6 s, afterglow time of 0 s and damaged length of 11.2 cm, respectively. After 10 washes, the coated fabric retained its good flame-retardancy and anti-dripping properties. Furthermore, the flame-retardant mechanism of SPAE-WPU was investigated using various spectral analyses, which revealed that the P, N and S elements worked together to create non-combustible gas compounds, release free radicals, and promote dehydration and carbonization , leading to synergistic flame-retardant effects in both gas- and condensed-phase.
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FUEL
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2023
·
IF 7.4
Yaping Liu,Chao Pan,Xiaomin Qiu,Xianjie Li,Hengjun Gai,Meng Xiao,Tingting Huang,Quanhong Zhu,Hongbing Song
Although fossil fuels bring convenience to the production and life of people, they also cause numerous environmental problems. As a result of overexploitation, fossil fuels are gradually being depleted as a nonrenewable resource. Biomass is a green and renewable resource and has attracted people’s attention. As a platform compound derived from renewable biomass, 5-hydroxymethylfurfural (HMF) is important for in-depth research. The oxidative esterification process from HMF to dimethyl furan-2,5-dicarboxylate (FDMC) was achieved using a gold (Au) nanoparticle (NP) catalyst supported on poly(ionic liquid)s (PILs). The comprehensive characterization of the synthesized catalyst showed that the Au NPs were successfully loaded on PILs, and a strong interaction occurred between the catalyst support and the metal. In this work, 10 %Au/PILs-Cl-1 was used as the best catalyst. The conversion of HMF ( C HMF ) and the selectivity to FDMC ( S FDMC ) reached 95.08 % and 96.82 %, respectively, under the conditions of 120 °C, 1.5 MPa, 12 h, and 0.5 equiv. CH 3 ONa. In addition, cycling experiments indicated the stability and successfully recycling of 10 %Au/PILs-Cl-1 catalyst.
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SENSORS AND ACTUATORS A-PHYSICAL
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2023
·
IF 4.6
Ruizhen Li,Wanzhen Yuan,Yu Hu,Yonggang Zeng
Propranolol , a widely used β-adrenergic receptor antagonist drug with potential toxic effects to organisms and human beings, was not completely removed from environment through traditional wastewater treatments . It is necessary to sensitively and selectively monitor the trace content propranolol in various samples. In this work, a novel photoelectrochemical (PEC) aptasensor based on Au nanoparticles (NPs) modified g-C 3 N 4 /BiPO 4 heterojunction was successfully fabricated for detecting (S)-propranolol (S-Pro), an important racemic enantiomer of propranolol. Herein, g-C 3 N 4 was employed as visible light-active semiconductor. The photocatalytic activity of g-C 3 N 4 was enhanced via forming heterojunction with BiPO 4 to facilitate the separation and migration of photogenerated carriers . In addition, Au NPs with perfect conductivity and surface plasmon resonance (SPR) effect are not only beneficial to the electron transfer and visible light harvest of g-C 3 N 4 /BiPO 4 heterojunction, but also the crucial factor on assembling S-Pro-binding DNA aptamer via Au-S bonding. At the same time, as a π-π conjugated material, g-C 3 N 4 with large surface area also provides an excellent platform for loading Au NPs. Under the visible light illumination, the PEC aptasensor displayed high PEC performance. On such a sensor, specific captured S-Pro by the aptamer was quickly oxidized by the photogenerated holes to inhibit the recombination of the photogenerated carriers, enhanced the PEC response, and realized the detection of S-Pro. Under optimal conditions, the designed PEC aptasensor exhibited a wide linear range of 10 nM to 1000 nM with a low detection limit (defined as S/N = 3) of 2.55 nM. Moreover, the proposed sensor displayed high selectivity , good reproducibility, and general long-term stability. And the S-Pro in real sample was accurately detected using this proposed sensor.
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JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 38
·15035-15046
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IF 4.5
Wang Xiongwei,Ma Rui-Juan,Guo Tingyu,Zhang Xuewei,Wang Hui,Zhao Xu
Abstract The hydrogen iodide decomposition reaction of the sulfur-iodine (SI) cycle is realized by electrolysis at room temperature to achieve efficient hydrogen production, while iodine is recycled throughout the SI reaction. In this work, we report a facile hydrothermal method for the synthesis of sulfur-doped titanium dioxide (S- \(\hbox {TiO}_2\) ) nanosheets with evenly distributed on the Ti foil (S- \(\hbox {TiO}_2\) /Ti). The noble metal-free S- \(\hbox {TiO}_2\) /Ti electrode demonstrates excellent electrochemical catalytic performance for iodine evolution reaction. It can deliver a high current density of 100 mA/ \(\hbox {cm}^2\) with a potential of 1.05 V, which is close to 90% of that of precious metal platinum and 5.6 times of bare Ti foil. Furthermore, the S- \(\hbox {TiO}_2\) /Ti electrode is stable in a mixed acid solution of HI and \(\hbox {H}_2\hbox {SO}_4\) . Compared to \(\hbox {TiO}_2\) /Ti, diffuse reflectance spectroscopy and ultraviolet photoelectron spectroscopy analysis evidence a reduction in the band gap and work function of S- \(\hbox {TiO}_2\) /Ti due to the doping of sulfur. Correspondingly, the current efficiency approaches to 100% under the electrolysis constant voltage 1.30 V. Eventually, the detailed mechanism to describe the improvement of the electrocatalytic performance was suggested. Graphical abstract
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Journal of Materials Chemistry B
·
2023
·
IF 7
Wenbin Nan,Fan Wang,Hao Wang,Wenchi Xiao,Linxiao Li,Chao Zhang,Yulu Zhang,Linna Dai,Zhihao Xu,Guoyun Wan,Yongxue Wang,Hongli Chen,Qiqing Zhang,Yongwei Hao
Treating chronic wounds requires transition from proinflammatory M1 to anti-inflammatory M2 dominant macrophages. Based on the role of tumor extracellular vesicles (tEVs) in regulating the phenotypic switching from M1 to M2 macrophages, we propose that tEVs may have a beneficial impact on alleviating the overactive inflammatory microenvironment associated with refractory wounds. On the other hand, as a nitric oxide donor, S-nitrosoglutathione (GSNO) can regulate inflammation, promote angiogenesis, enhance matrix deposition, and facilitate wound healing. In this study, a guar gum-based hydrogel with tEVs and GSNO was designed for the treatment of diabetic refractory wounds. This hybrid hydrogel was formed through the phenyl borate bonds, which can automatically disintegrate in response to the high reactive oxygen species (ROS) level at the site of refractory diabetic wounds, releasing tEVs and GSNO. We conducted a comprehensive evaluation of this hydrogel in vitro, which demonstrated excellent performance. Meanwhile, using a full-thickness excision model in diabetic mice, the wounds exposed to the therapeutic hydrogel healed completely within 21 days. The increased closure rate was associated with macrophage polarization and collagen deposition, accelerated fibroblast proliferation, and increased angiogenesis in the regenerating tissues. Therefore, this multifunctional hybrid hydrogel appears to be promising for clinical applications.
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JOURNAL OF PHYSICS D-APPLIED PHYSICS
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2023
·Vol. 56
·期 49
·495103
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IF 3.4
Yujiao Ma,Yuzhou Sun,Zihan Zhang,Haokai Zhao,Haifeng Gao,Qing Zhou,Wenbo Li,Xiaoyun Teng,Chao Gao,Wei Yu
In this paper, the open-circuit voltages (VOC) of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells were improved by soaking the CZTSSe films in Cd/NH3 solutions before the deposition of buffer layers. The effects of Cd/NH3 soaking on the properties of CZTSSe films and solar cells were investigated in depth. We found Cd/NH3 soaking can promote downward band bending of the CZTSSe layer at the surface region. In addition, the Cd/NH3 soaking can eliminate the deep level acceptor in CZTSSe and decrease the density of the defects at the absorber/buffer interface. These effects can significantly reduce the carrier recombination in the depletion region of CZTSSe solar cells. As a result, the VOC of CZTSSe solar cells were increased from ∼460 mV to ∼480 mV, the efficiency of the best CZTSSe solar cell was increased from 10.2% to 11.6% by the Cd/NH3 soaking process.
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Songyu Yang,Kailin Wang,Qiao Chen,Yan Wu
S-scheme heterostructure photocatalysts can achieve highly efficient solar energy utilization. Here, single-atom Ni species were deposited onto TiO 2 /g-C 3 N 4 (TCN) composite photocatalyst with an S-scheme heterojunction for highly efficient photocatalytic water splitting to produce hydrogen. Under solar irradiation, it realized the hydrogen production activity of 134 µmol g –1 h –1 , about 5 times higher than the TCN without atomic Ni. In-situ Kelvin probe force microscopy characterization and the density functional calculation certify that by forming the S-scheme heterojunction, the photo-excited electrons from the TiO 2 combine with the photogenerated holes at the coupled g-C 3 N 4 driven by a built-in electric field. More importantly, the single-atom Ni species stabilized the photogenerated electrons from the g-C 3 N 4 could effectively enhance the charge separation between the holes on the valence band of TiO 2 and electrons at the conduction band of g-C 3 N 4 . Meanwhile, the Ni atoms act as the surface catalytic centers for the water reduction reaction, which greatly improves the reactivity of the photocatalyst. The present work provides a new approach for developing noble metal-free heterojunctions for high-efficiency photocatalysis.
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WATER RESEARCH
·
2021
·
IF 11.236
Jingxin Yang,Yujie Luo,Xianghui Fu,Zijun Dong,Chuan Wang,Hong Liu,Chengchun Jiang
Transition metal catalyzed sulfite auto-oxidation is a promising technology used in water and wastewater treatment for the elimination of contaminants. In the literature, this process has been reported to be efficient only in the presence of oxygen. However, in this study, we unexpectedly found that the degradation of diatrizoate (DTZ) by a system based on the combination of copper ion and sulfite (Cu(II)/S(IV)) reached over 95% under anaerobic conditions , but was considerably retarded under aerobic conditions at pH 7. Furthermore, it was found that Cu(I), generated from the cleavage of the CuSO 3 complex, was the main reactive species responsible for the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions. In fact, the absence of oxygen promoted the accumulation of Cu(I). The concomitant release of the iodide ion with the degradation of DTZ indicated that the anaerobic degradation of DTZ by the Cu(II)/S(IV) system mainly proceeded through the deiodination pathway, which was also confirmed by the detection of deiodinated products. The anaerobic degradation of DTZ was favored at higher initial concentrations of Cu(II) or sulfite in this system. Since the CuSO 3 complex, the precursor of Cu(I), was formed mainly at pH 7, the highest anaerobic degradation of DTZ was achieved at pH 7. An increase in reaction temperature considerably enhanced the degradation of DTZ by the Cu(II)/S(IV) system with an apparent activation energy of 119.4 kJ/mol. The presence of chloride, bicarbonate and humic acid slightly influenced the anaerobic degradation of DTZ. The experiments with real water samples also demonstrated the effectiveness of the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions.
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Science China-Technological Sciences
·
2021
·Vol. 65
·期 2
·272-281
·
IF 3.572
Meng FanCheng,Xu Bin,Long Tao,Cheng Sheng,Li Yong,Zhang YongYi,Liu JieHua
Conductive carbon structure has been considered as a promising sulfur-hosting material as the cathode of lithium-sulfur batteries. However, the issue of polysulfide shuttling requires an additional component to help restrict and convert sulfur substances. Herein, in this work, hollow and porous carbon nanospheres (HCS) are synthesized by a template method and a high-temperature carbonization treatment. A thin layer of ZnS coating is then deposited on the HCS-based sulfur (ZnS@HCS/S) cathode with controlled thickness, and the overall electrochemical properties are systematically evaluated. Results show that with 30 nm-thick ZnS coating, the cathode reveals an improved capacity of 1411 mA h g −1 , and higher capacities from 0.2 to 3 C rate compared with bare HCS/S cathode. Moreover, the ZnS coating also enhances the cycling stability of ZnS@HCS/S cathode over 280 cycles at 0.5 C, with only 0.2% capacity decay per cycle. This work demonstrates potential applications for high-performance lithium-sulfur batteries.
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危险品化学品经营许可证（带存储）