Polymers
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2023
·Vol. 15
·期 2
·413
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IF 5
Jialin Xu,Kuo Zhou,Linlin Qin,Zaiming Tan,Shijing Huang,Peigao Duan,Shimin Kang
The chemical recycling of end-of-life polylactic acid (PLA) plays roles in mitigating environmental pressure and developing circular economy. In this regard, one-pot tandem alcoholysis and hydrogenation of PLA was carried out to produce 1,2-propanediol, which is a bulk chemical in polymer chemistry. In more detail, the commercially available Raney Co was employed as the catalyst, and transformation was conducted in ethanol, which acted as nucleophilic reagent and solvent. Single-factor analysis and Box–Behnken design were used to optimize the reaction conditions. Under the optimized condition, three kinds of PLA materials were subjected to degradation. Additionally, 74.8 ± 5.5%, 76.5 ± 6.2%, and 71.4 ± 5.7% of 1,2-propanediol was yielded from PLA powder, particle, and straws, respectively, which provided a recycle protocol to convert polylactic acid waste into value-added chemicals.Keywords:polylactic acid;alcoholysis;hydrogenation;1,2-propanediol;PLA straws
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ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Lei Jia,Linwen Jiang,Jiawen Hu,Jiawei Jin,Siqin Yan,Anhua Wu,Xiaofeng Zhang
Optimizing the impedance matching via electromagnetic adjustment is considered an effective strategy to accomplish exceptional electromagnetic wave absorption (EMA) performance. Here, we report an efficient and green process to obtain the carbonitriding FeCoNiCr high-entropy alloys (HEAs) with flake-shaped morphology by using organic cyanide (Dicyandiamide, C2H4N4) as nitrogen and carbon sources. The carbonitriding effects on the phase structure, magnetic properties, mechanical hardness, corrosion resistance, high-temperature oxidation resistance, and EMA performances were investigated systematically. The carbonitriding process optimized the impedance match by decreasing the dielectric constant via introducing the nonmetallic C and N. The #CN10 sample exhibited outstanding EMA performances with a minimum reflection loss of −32.3 dB at 7.89 GHz and a broad effective bandwidth of 4.46 GHz, which covered the majority of X-band. In addition, the carbonitriding FeCoNiCr HEAs had great mechanical properties, excellent corrosion resistance, and high-temperature oxidation resistance, indicating excellent adaptability to harsh environments as well as good EMA performances. This work provides a new idea for the preparation and design of carbonitriding EMA materials.
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APPLIED THERMAL ENGINEERING
·
2023
·
IF 6.4
Yimo Liu,Zhongbao Liu,Zepeng Wang,Weiming Sun,Fanzhao Kong
Photovoltaic (PV) power generation, which converts sunlight into electricity, stands as a pivotal mode of solar energy utilization. The thermal effect poses a significant challenge for all types of PV panels under real operating conditions, as it diminishes both the photovoltaic conversion efficiency and the lifespan of the PV panels. This paper presents a novel passive cooling approach for silicon-based photovoltaic panels, employing night-time hygroscopic hydrogel adsorption, daytime desorption, and subsequent water evaporation for cooling. Both laboratory and outdoor experiments were conducted to validate this strategy. Experimental results reveal that under simulated laboratory light of 1 kW m −2 , the hydrogel cooling layer delivers an average cooling power of 288.2 W m −2 . It lowers the PV panel temperature by 9.9 °C and enhances both the maximum power and efficiency at equilibrium by 5.92% and 5.93%, respectively. Outdoor experiments in Beijing, China, during summer demonstrated that this method reduced the average daytime temperature of the PV plate by 7.1 °C and increased the average maximum power by 5.21%. The hydrogel layer's high hygroscopicity enables it to support passive cooling effectively all day. Passive cooling strategies for PV panels, leveraging the atmospheric water harvesting cycle, face fewer application constraints. They offer the potential to increase power generation and reduce CO 2 emissions from PV plants both now and in the future.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2023
·
IF 4.4
Boxu Wang,Zheng Liu,Zhihong Li,Ningyi Xu,Xuejiao Zhang,Ruifang Su,Junyang Wang,Rui Jin,Chunyan Sun
Hg 2+ is highly toxic to human health and ecosystem. In this work, based on the unique fluorescent property of 2-Aminopurine (2-AP), the formation of T-Hg 2+ -T mismatch structure and the signal amplification of exonuclease III (Exo III) assisted target cycle, a fluorescent probe for facile and sensitive detection of Hg 2+ is constructed. The hairpin-looped DNA probe is rationally designed with 2-AP embedded in the stem and thymine-rich recognition overhangs extended at the termini. The cleavage of the double stranded DNA stem with stable T-Hg 2+ -T pairs catalyzed by Exo III is prompted to happen upon recognition of trace Hg 2+ . Under the optimal reaction conditions, there is an excellent linear relationship between Hg 2+ concentration and fluorescence intensity in the range of 7.5–200 nM with a detection limit of 0.38 nM. In addition, the detection results of Hg 2+ in Songhua River water and fish samples are satisfactory. The fluorescent probe avoids labeling additional quenchers or quenching materials and has strong anti-interference ability. Thus, the fluorescent probe has a broad prospect in practical application.
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Journal of Energy Storage
·
2023
·
IF 9.4
Wenhao Fan,Jianxun Zhao,Dayong Liu,Qingcheng Liang,Wanqiang Liu,Xin Guo,Qingshuang Wang,Heng Liu,Peng Chen,Shang Gao,Yong Cheng,Xinwei Wang
The current hydrogen storage alloys used for Ni-MH battery negative electrode are difficult to guarantee excellent performance in terms of discharge capacity and cycle stability. Co 0.9 Cu 0.1 Si alloy has been widely investigated as a negative electrode material for nickel hydrogen battery, but its capacity and cycle stability need to be improved for commercial applications. In this work, Co 0.9 Cu 0.1 Si alloy was prepared by mechanical alloying. Molybdenum carbide (Mo 2 C) was loaded on multi-walled carbon nanotubes (MWCNTs) by in-situ carburizing . In order to improve the electrochemical hydrogen storage performance of Co 0.9 Cu 0.1 Si alloy, 5 wt% MWCNTs, Mo 2 C and molybdenum carbide modified multi-walled carbon nanotubes (Mo 2 C@MWCNTs) were added to Co 0.9 Cu 0.1 Si alloy via mechanical alloying method. The structure and morphology of the composites were characterized by XRD and SEM. The discharge capacity, cyclic stability and high rate discharge performance of the composites were tested, the electrochemical performance of the composites was investigated by three-electrode battery system. The composite materials have better discharge capacity, cycle stability and electrochemical performance compared with the pristine alloy. The Co 0.9 Cu 0.1 Si alloy doped with 5 wt% Mo 2 C@MWCNTs-2 has the best electrochemical hydrogen storage performance among all the composite materials. Its optimal discharge capacity is 609.9 mAh/g and its maximum capacity retention rate is 64.7 %. The enhancement of the electrochemical hydrogen storage performances of the composites are due to the high conductivity and high specific surface area of MWCNTs and the high catalytic activity of Mo 2 C. The synergistic effect of MWCNTs and Mo 2 C can improve the electrochemical hydrogen storage performances of the composites.
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ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Site Luo,Yangjie Li,Wei Yang,Wenjing Gao,Haihu Yu,Niu Huang
A simple yet powerful approach to obtain structural color is the amorphous assembly of colloidal spheres, which is also referred to as the amorphous photonic structure or photonic glasses (PGs). Additionally, the functionalization of the colloidal spheres as building blocks can further endow the resulting PGs with multifunctions. Herein, we have developed a facile strategy to prepare SiO2 colloidal spheres with concentrically embedded carbon dots (CDs). Notably, the CDs are prepared and silane-functionalized simultaneously, which enables the perfect incorporation of CDs into the Si–O network during the Stöber reaction and thus leads to the formation of a concentric SiO2/CD interlayer within the obtained SiO2 spheres. Moreover, the obtained SiO2/CD spheres can be applied as photonic pigments by assembling them into PGs, which exhibit structural color under daylight and fluorescence under UV illumination. With incorporation of carbon black, the structural color saturation and fluorescence intensity can be further manipulated. Owing to the combination of structural colored PGs and fluorescent CDs, our study can offer inspiration for color- and fluorescence-related applications such as sensing, in vivo imaging, LEDs, and anticounterfeiting.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Yuexi Zheng,Zhiguo Ye,Xinyuan Peng,Shaojie Zhuang,Duosheng Li,Zhong Jin
Oxygen evolution reaction (OER) electrocatalysts in acidic media, except for precious IrO 2 , have difficulty realizing good electrocatalytic activity and high electrochemical stability simultaneously. However, the scarcity of IrO 2 as an acidic OER electrocatalyst impedes its large-scale application in hydrogen generation, organic synthesis, nonferrous metal production and sewage disposal. Herein, we report the design and fabrication of a nanoporous TiMnCoCN compound based on the nanoscale Kirkendall effect, possessing an intriguing self-adjusting capability for the oxygen evolution reaction (OER) in a 0.5 M H 2 SO 4 solution. The nanoporous TiMnCoCN compound electrode for the acidic OER displays a low overpotential of 143 mV for 10 mA cm −2 and exhibits no increase in potential over 50,000 s, which is ascribed to the self-adjusting ability, Carbon/nitrogen (C/N) incorporation and nanoporous architecture. The concentration of inert TiO 2 on the reconstructed surface of the compound can self-adjust with the change in OER potential via a cobalt-dissolved vacancy approach according to the stabilization requirement. In this work, the self-reconstruction law of surface structure was discovered, providing a novel strategy for designing and fabricating nonnoble OER electrocatalysts with superior catalytic performance and robust stability in acidic media.
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MODERN PHYSICS LETTERS B
·
2023
·
IF 1.9
Yaqi Chen,Xin Fan,Shan Gao,Wenting Ji,Xinjian Li,Yuewen Zhang,Hongan Ma,Xiaopeng Jia
Electronegative S-filled skutterudite compounds have attracted considerable attention due to scattering of low-frequency phonons (35–50 cm − 1 ), but there are few reports on S-filled double-substituted skutterudite. In this work, a series of S-filled Te-Sn double-substituted skutterudite compounds were synthesized using high pressure and high temperature (HPHT) method. The phase composition, microstructure, and thermoelectric properties of S x Co 4 Sb 1 1 Te 0 . 7 Sn 0 . 3 ( x = 0 , 0.05, 0.10, 0.20) samples were systematically determined. The results show that the introduction of S increases the substitution limit of Te in the Sb site. Under the combined effect of the sample synthesis pressure and S filling, the nucleation density of the sample grains increases and the grain size decreases. At the same time, there are numerous special microstructures in the samples synthesized in a high-pressure environment. Thermoelectric performance studies show that a small amount of S filling optimizes the Seebeck coefficient of the sample and increases the power factor (PF). With an increase of the amount of S introduced, the thermal conductivity of the samples decreases significantly. Therefore, the maximum zT value of an S 0 . 0 5 Co 4 Sb 1 1 Te 0 . 7 Sn 0 . 3 sample synthesized at 2.5 GPa pressure is 0.17 at room temperature. The maximum zT value of the sample is 1.26 at 773 K.
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CORROSION SCIENCE
·
2022
·
IF 7.72
Zhichao Shang,Xiaoping Cai,Xinyang Jiao,Yan Zheng,Baojing Zhang,Farshid Pahlevani,Peizhong Feng
With the increasing demand for high-temperature gas filtration, porous intermetallic compounds have attracted much attention. In this study, high porosity CoAl with 3D microstructures was prepared using the thermal explosion. The link between the pore structure , mechanical and oxidation resistance of the product was established using 3D-XRM. Moreover, an oxidation corrosion test was conducted in fluid and static air at 700–900 °C for up to 120 h. During the rapid growth stage, the mass gain was dominated by the inward diffusion of O, while during the slow growth stage, it was dominated by the outward diffusion of Al.
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MATERIALS SCIENCE AND TECHNOLOGY
·
2022
·
IF 2.06
Hong Zeng,Wenbin Liu,Chongbin Wei
This study investigated the microstructure and properties of cemented carbides before and after the addition of Ru. The hardness and elastic modulus of the binder phase of Ru-containing cemented carbides were higher, and the hardness at room temperature and high temperature were also high. In particular, the oxidation resistance of Ru-containing cemented carbides was enhanced at high temperatures. Therefore, the solid solution-strengthening effect of the binder phase containing Ru was significant, which was conducive to the improvement of the high-temperature hardness and enhancement of the high-temperature characteristics of the alloy.
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CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Xin Fan,Dayi Zhou,Yaqi Chen,Xinjian Li,Shan Gao,Wenting Ji,Yuewen Zhang,Qi Chen,Hongan Ma,Xiaopeng Jia
Compared to Te, Ni is found in abundance in the earth's crust. At the same time, the mechanical properties of Ni atom-substituted skutterudite are significantly improved. In this study, a series of S-filled Ni-substituted skutterudite compounds were synthesized by a high-pressure and high-temperature (HPHT) method in the synthesis pressure range of 1.0–3.0 GPa. The phase composition, microscopic morphology, and electrothermal transmission properties of the S x Co 3.6 Ni 0.4 Sb 12 ( x = 0, 0.05, 0.10, 0.20) samples were systematically characterized. Phase composition analysis showed that the introduction of S atoms into the intrinsic pores of skutterudite can improve the solid solution limit of Ni atoms in the Co sites of skutterudite. The filling limit of S increased with the synthetic pressure. Moreover, microscopic morphology analysis revealed that the filling of S atoms inhibited the growth of grains. A large number of lattice fringes in different directions were found in the sample, containing abundant microstructures such as lattice distortions and dislocation defects. Compared with the synthesized samples, S 0.05 Co 3.6 Ni 0.4 Sb 12 synthesized at 1.0 GPa had a maximum room temperature power factor of 7.98 × 10 −4 Wm −1 K −2 . The electrical properties of S 0.05 Co 3.6 Ni 0.4 Sb 12 samples stored for 6 months without any protective measures were tested at room temperature. No obvious changes in performance were observed, which proved that the HPHT method can synthesize stable samples. After several thermal cycles, the electrical properties of the S 0.05 Co 3.6 Ni 0.4 Sb 12 sample was tested for variable temperature, and it was found that the sample still had good stability. How the substitution of S atoms with Ni atoms reduces the lattice thermal conductivity can be explained by fitting the Callaway model. The S 0.05 Co 3.6 Ni 0.4 Sb 12 sample synthesized at 1.0 GPa had a maximum zT value of 0.46 at the test temperature of 773 K, which decreased to 0.43 after multiple thermal cycles at the same temperature.
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ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Jiahuang Jian,Hongjun Kang,Xianshu Qiao,Kai Cui,Yang Liu,Yang Li,Wei Qin,Xiaohong Wu
Water electrolysis is an effective method of obtaining hydrogen energy, which is the key to achieve the global “carbon neutrality” goal. Molybdenum disulfide (MoS2) with a layered structure is considered to be a competitive hydrogen evolution reaction (HER) catalyst. However, until now, metal-atom-modified 1T-phase MoS2 with rich edge active sites has rarely been reported. Herein, we first report Co and Al co-optimized 1T-phase MoS2 (CA-1T-MoS2) with rich edge active sites using a simple one-step ball-milling method. The CA-1T-MoS2 exhibits an outstanding HER performance with an overpotential value of 102 mV at 10 mA cm–2 in 1.0 M KOH. The density functional theory (DFT) results prove that the introduction of Co and Al atoms on the rich edges of 1T-MoS2 provides rich active sites, improves the electrical conductivity, accelerates the distortion of H2O to generate H* and reduces the adsorption energy of hydrogen. Thus, CA-1T-MoS2 exhibits a prominent HER performance. This work provides a novel strategy for the simple preparation of metal-atom-modified 2D transition-metal sulfide HER catalysts with rich edge active sites.
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