查找使用阿拉丁产品的科研文献

Firmly-supported porous fabric fiber photocatalysts: TiO2/porous carbon fiber cloth composites and their photocatalytic activity

Bing Bai,Linlin Qiu,Deqiang Mei,Zhengfei Jin,Lixin Song,Pingfan Du

The use of a support may overcome the limitations of nano-photocatalysts (poor recyclability, secondary pollution, and agglomeration that decreases photocatalytic activity); however, supports such as fibers, fabrics, films, and foams, still exhibit many defects (low loadings, non-uniform particle loadings, and insufficient loading firmness). In this study, we fabricated TiO 2 /porous carbon fiber cloth through a microwave hydrothermal method and thermal reduction. The highly porous structure of fiber could provide abundant space to firmly-supported TiO 2 nanoparticles. Therefore, the results showed that large amounts of TiO 2 were uniformly and firmly loaded onto the porous carbon fiber cloth, and the obtained composite exhibited excellent photocatalytic activity. The initial loading rate reached 51 wt.%. Even after 10 photocatalytic cycles, the pollutant degradation rate exceeded 95%, and 55% of TiO 2 was retained, showing its stability. This investigation provides a method to prepare supported photocatalysis, which can greatly promote their practical applications for wastewater treatment.

Sorption/desorption of Eu(III) on halloysite and kaolinite

Junming Zhou,Hongmei Liu,Dong Liu,Peng Yuan,Hongling Bu,Peixin Du,Wenxiao Fan,Mengyuan Li

Weathered crust elution-deposited rare earth (WED-RE) ores are important rare earth element (REE) resources around the world. In these ores, the REE are believed to mainly exist as exchangeable REE(III) ions on the surfaces of clay minerals, such as tubular halloysite and platy kaolinite . However, the mechanisms underlying the sorption and desorption of REE(III) ions on clay minerals in the environment of weathered crusts remain ambiguous. In this study, the sorption/desorption characteristics of Eu(III) ions onto halloysite and kaolinite were investigated. The results revealed that Eu(III) was adsorbed onto both clay minerals through inner-sphere complexation and outer-sphere complexation, where the former was the primary sorption mechanism. Halloysite displayed a higher sorption capacity for Eu(III) than kaolinite in a weakly acidic environment (pH 4–6). The desorption efficiency increased with the increasing concentration of NH 4 + ions. When the NH 4 + concentration was 0.002 mol/L, which is similar to the typical cation concentration of groundwater/rainwater, the amount and rate of Eu(III) desorption from halloysite were lower than those from kaolinite. The desorption of Eu(III) ions from the two clay minerals is proposed to be governed by the attraction between the outer-sphere complexes and clay minerals when the NH 4 + concentration is 0.002 mol/L. Therefore, halloysite has a higher sorption capacity and stronger retention capacity for Eu(III) than kaolinite, which suggests that halloysite may play a greater role in REE(III) enrichment in WED-RE ores than kaolinite owing to the similar chemical properties of REE(III) ions. The fundamental results obtained in this study afford new insights into the migration of REE and the role of clay minerals in REE enrichment during ore formation.

MoS2@In2S3/Bi2S3 Core-shell dual Z-scheme tandem heterojunctions with Broad-spectrum response and enhanced Photothermal-photocatalytic performance

Yichao Wang,Zipeng Xing,Huanan Zhao,Sijia Song,Meijie Liu,Zhenzi Li,Wei Zhou

Oxygen-doped MoS 2 @In 2 S 3 /Bi 2 S 3 core-shell dual Z-scheme tandem heterojunctions are fabricated via two-step hydrothermal methods. In 2 S 3 and Bi 2 S 3 nanosheets grow on the outer surface of oxygen-doped MoS 2 spheres, and the tight interface between the spheres could ensure stable electron transfer. MoS 2 with oxygen defects could inhibit the recombination of photo-induced electron-hole pairs. The unique core-shell structure increases the interface area and provides adequate surface reactive sites for the reactants. The resultant MoS 2 @In 2 S 3 /Bi 2 S 3 shows broad-spectrum response and excellent photothermal effect, which is beneficial to trigger the near-field temperature rise and promote the photocatalytic process. The MoS 2 @In 2 S 3 /Bi 2 S 3 exhibits excellent photocatalytic H 2 evolution rate of 973.42 μmol h −1 g −1 , and the degradation efficiency of tetracycline within 90 min is 99.6%, which is ∼ 10 times higher than that of pristine MoS 2 . It can be ascribed to the unique core-shell dual Z-scheme tandem heterojunction structure facilitates the transfer and spatial separation of photogenerated electron-hole pairs, and greatly prolongs the carrier lifetime. In addition, the long-term stability indicates the potential applications due to the core-shell dual Z-scheme tandem structure inhibiting the photocorrosion of sulfides.

Flexible Strain Sensor Based on Conductive Hydrogel/KC@PDMS for Neck Motion Control Wheelchair Using EMD-LSTM Algorithm

Xiaoming Wang,Longbo Xiong,Wentao Dong,Zhilong Guo,Yifeng Huang,Daojin Yao

Room temperature synthesis of piperazine-based nitrogen-rich porous organic polymers for efficient iodine adsorption

Yingyi Zhao,Wenjun Lu,Yinan Zhang,Xianmin Liu,Baiwang Sun

The proper management of radioactive iodine waste generated from nuclear energy has become one of the challenges in the sustainable development of nuclear power. With the continuous development of POPs materials, their high-efficiency iodine adsorption performance has been demonstrated to be related to the material's structural units and porous structure. In light of this, three two-dimensional porous organic polymers were synthesized using environmentally friendly non-metallic catalyzed coupling reactions. Their excellent chemical stability and nitrogen-rich porous structure endowed them with the ability to exhibit outstanding capture performance and recyclability in various media. Its iodine adsorption performance reached 3.81 g/g, 3.55 g/g and 3.19 g/g respectively. The research results provide a potential pathway for the design and synthesis of organic porous polymers with good chemical stability and iodine adsorption performance, showcasing the significant potential of POP-PDTE, POP-PDTK, and POP-PDTB in capturing radioactive pollutants.

Identification of novel bioactive proanthocyanidins with potent antioxidant and anti-proliferative activities from kiwifruit leaves

Ji-Min Lv,Mostafa Gouda,Alaa El-Din Bekhit,Ya-Ke He,Xing-Qian Ye,Jian-Chu Chen

Agro-wastes contribute major social, economic, and environmental challenges for food production and circular economy systems. The current increasing demand for clean label food production and use of natural bioactive compounds could turn these challenges into opportunities providing avenues for proper utilization of agro-wastes to produce valuable products. This study aimed to investigate the potential use of kiwifruit ( Actinidia chinensis ) leaves as a source of proanthocyanidins (PAs) bioactive phenolic phytochemicals . Kiwifruit leaves PAs were extracted, purified, identified, and evaluated for their antioxidant and anti-proliferative activities. The structural composition of the purified PAs was characterized using HPLC-QTOF-MS/MS and MALDI-TOF-MS. The results showed that purified kiwifruit leaves PAs (PKLPs) comprised mainly procyanidins , propelargonidins , and prodelphindins ranging from dimers to hexamers with (epi)catechin as terminal units and (epi)afzelechin or (epi)gallocatechin as dominant extension units. This study reports the structure of novel PKLPs monomer fractions was unique compared to the PAs that extracted from the other plant sources. The PKLPs exhibited higher phenolic content than the skin and flesh of several kiwifruit cultivars. Moreover, the PKLPs exhibited higher in vitro antioxidant activity in chemical-based (DPPH, ABTS , and FRAP) assays and H 2 O 2 -induced injury cell model than ascorbic, Trolox , and catechin ( p  < 0.01). A remarkable dose-dependent anti-proliferation activity (IC 50  = 186.04 ± 2.61 μg/mL) against HepG2 cells was observed. In conclusion, this study demonstrated that kiwifruit leaves waste could serve as a sustainable and low-cost source of PAs, a group of multi-functional bioactive compounds that plays a key role in the food and pharmaceutical industries.

Recycling of arsenic-containing biohydrometallurgy waste to produce a binder for cemented paste backfill: Mix proportion optimization

Yingliang Zhao,Jingping Qiu,Shiyu Zhang,Zhenbang Guo,Pinqi Wu,Xiaogang Sun,Xiaowei Gu

Arsenic-containing biohydrometallurgy waste (BW) is used to prepare a cementitious material , on the one hand, to solve the problem of lack of cheaper and greener binder for cemented paste backfill (CPB), on the other hand, to alleviate the arsenic pollution caused by BW. The binders were prepared by mixing blast furnace slag (BFS), BW, and ordinary Portland cement (OPC). The influence of mix proportions on the binder properties was investigated, including reaction kinetics, strength development, phase assembles of hydration products and arsenic (As) immobilization effects. Isothermal calorimeter analysis suggests that the binder reaction kinetics were highly determined by the mix proportions, and more BW addition decreased the reaction rate according to the Krstulovic-Dabic model. The optimal mix proportion of binder is 65–30-5, i.e., 65 wt% blast furnace slag, 30 wt% BW, and 5 wt% OPC. The compressive strength of this sample after curing for 3 days and 60 days is about 9.25 MPa and 40.88 MPa, respectively, and the hydration products mainly consist of ettringite and calcium silicate aluminate hydrate (C-(A)-S-H). Additionally, arsenic can be effectively immobilized in the binder, resulting from the denser structure (physical encapsulation) and ion exchange between arsenate and sulfate in ettringite.

Preparation and application of macromolecules with a fluorescence effect in polymer processing

Meng-Di Chen,Guo Zhang,Shi-Chang Chen,Xian-Ming Zhang,Wen-Xing Chen

In this study, 9-anthracenemethyl methacrylate (AMMA) and styrene (St) as monomers and benzoyl peroxide as an initiator were used to synthesize P(St-co-AMMA), a macromolecule tracer with a fluorescence effect, via free radical copolymerization. A fluorescent online detection device was built on the basis of the principle of fluorescence online detection by using the single-screw extrusion platform of a torque rheometer to explore the effect of the amount of macromolecular tracer and screw speed on the residence time distribution of polystyrene in single-screw extrusion. Fourier transform infrared spectroscopy, 1H-NMR, thermal stability, fluorescence properties, and rheological properties show that the resulting product P(St-co-AMMA) has a degree of thermal stability, fluorescence, and rheological properties similar to polystyrene, so this product can be used to characterize the residence time distribution during single-screw extrusion. The amount of macromolecular tracer P(St-co-AMMA) does not affect the residence time distribution of polystyrene during single-screw extrusion processing, meanwhile, the minimum residence time decreases and the residence time distribution becomes narrow as the screw speed increases, that is, the axial mixing capacity of the single-screw extruder decreases as the screw speed increases.

Electron localization engineering in entropy-mediated heterostructures for amplifying interfacial polarization

Zhengyu Zhang,Zegeng Chen,Jun Li,Xinqi Wang,Nandong Deng,Zhuyu Hua,Yang Hong,Xin Sun,Yang Li,Zhongxiang Zhou

Electron localization engineering via Fe/Cr doping tailors work function differences to amplify dielectric loss in M 3 S 4 /MS-type and M 9 S 8 /MS-type heterostructures. • Entropy-mediated Fe/Cr doping causes the different heterostructures compositions and regulated electron localization capabilities to modulate the work functions of phases, maximizing work function difference to 1.46 eV. • Entropy-mediated Fe/Cr co-doping achieves −46.57 dB reflection loss and 4.40 GHz bandwidth, elucidating entropy-mediated doping via electron localization for amplifying interfacial polarization. Interfacial polarization governed via work function differences offers a critical avenue for amplifying dielectric loss. However, in entropy-mediated heterogeneous systems, the underlying electron-structure principles that manipulating work functions remains unraveled, hindering interfacial polarization maximization. Herein, we exploit entropy-mediated Fe/Cr doping to tailor electron localization characteristics in medium-/high-entropy sulfide heterostructures. It is noted that Fe-doped samples form M 3 S 4 /MS heterostructures, while Cr-doped and Fe/Cr co-doped samples adopt M 9 S 8 /MS heterostructures, where the electron localization of Fe-related electrons is higher compared to Cr. The different heterostructures compositions and regulated electron localization capabilities modulate the work functions of phases. This elective doping creates a stepwise increase in interfacial work function difference from 0.91 eV (Fe-doped quaternary M 3 S 4 /MS-type pair) to 1.14 eV in Cr-doped quaternary M 9 S 8 /MS-type interface. Finally this difference reaches maximum of 1.46 eV in consistent M 9 S 8 /MS-type quinary heterostructure (CoNiFeCrAl-S, 5-HES), amplying interfacial polarization loss. The increase of metal species secondarily enhance vacancy-induced dipole polarization and slightly enhance conduction loss. Therefore, these effects award 5-HES yield a improved reflection loss (−46.57 dB) and an effective absorption bandwidth (4.40 GHz). This work elucidates the mechanistic role of entropy-mediated doping in work function tuning through electron localization within this sulfide system, providing electronic-structure insights for doping-based electromagnetic heterostructures to amplify interfaces effect. Download: Download high-res image (444KB) Download: Download full-size image

Application of a Core-Shell Structure Nano Filtration Control Additive in Salt-Resistant Clay-Free Water-Based Drilling Fluid

Gang Wang,Wanjun Li,Shixin Qiu,Jitong Liu,Zhiting Ou,Xiaogang Li,Fei Ji,Liang Zhang,Shanshan Liu,Lili Yang,Guancheng Jiang

When drilling into a reservoir, the drilling fluid containing bentonite is prone to solid phase invasion, causing serious damage to the reservoir, and the conventional API barite suspension stability is poor, which makes it easy to cause sedimentation and blockage. Therefore, in order to avoid accidents, we use ultrafine barite to obtain a good suspension stability. More importantly, the method of modifying zwitterionic polymers on the surface of nano-silica is used to develop a temperature-resistant and salt-resistant fluid loss reducer FATG with a core-shell structure, and it is applied to ultra-fine clay-free water-based drilling fluid (WBDF). The results show that the filtration loss of clay-free drilling fluid containing FATG can be reduced to 8.2 mL, and AV can be reduced to 22 mPa·s. Although the viscosity is reduced, FATG can reduce the filter loss by forming a dense mud cake. The clay-free drilling fluid system obtained by further adding sepiolite can reduce the filtration loss to 3.8 mL. After aging at 220 °C for 15 d, it still has significant salt tolerance, the filtration loss is only 9 mL, the viscosity does not change much, a thinner and denser mud cake is formed, and the viscosity coefficient of the mud cake is smaller. The linear expansion test and permeability recovery evaluation were carried out. The hydration expansion inhibition rate of bentonite can reach 72.5%, and the permeability recovery rate can reach 77.9%, which can meet the long-term drilling fluid circulation work in the actual drilling process. This study can provide guidance for technical research in related fields such as reservoir protection.Keywords:clay-free;drilling fluid;filtration control agent;salt resistance

Hydrodeoxygenation of condensed lignins followed by acid-mediated methylolation enables preparation of lignin-based wood adhesives

Guangxu Yang,Zhenggang Gong,Bei Zhou,Xiaolin Luo,Jing Liu,Guanben Du,Chengke Zhao,Li Shuai

Lignin is a phenolic polymer, making it a sustainable alternative to phenol for synthesizing lignin–phenol–formaldehyde (LPF) adhesives. However, technical lignins produced in pulping or biorefining processes are generally highly condensed and have low reactivity, limiting their uses in synthesizing phenolic-based adhesives. Herein, we report a two-step strategy to produce lignin-based wood adhesives with industrially available technical lignins through hydrodeoxygenation followed by acid-mediated methylolation of aromatic C2/6 positions to improve the flowability, water resistance, and crosslinking ability of lignins. We demonstrated that this biobased lignin–formaldehyde adhesive had a lighter color and far better adhesion performance compared to traditional LPF resins prepared from base-mediated methylolation of lignins. Mechanistic investigation suggests that the chemical crosslinking of methylolated lignin to form diarylmethane structures and the physical interlocking interaction at the interfaces of wood veneers contribute to the strength of plywood.

Ru-modulated morphology and electronic structure of nickel organic framework bifunctional electrocatalyst for efficient overall water splitting

Jin Lin,Hong Wang,Chao Wang,Li Guo,Yanzhong Wang

Metal-organic frameworks (MOFs) are considered as prospective electrocatalysts for water splitting due to their adjustable pore structure and abundant active sites. However, the rational design of MOFs with excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performances is still an enormous challenge. Herein, Ru-doped nickel thiophene dicarboxylic acid (Ni-TDA)/nickel foam (NF) were prepared via a one-pot solvothermal method , and their morphologies and electronic structures can be facilely modulated by Ru doping contents. The as-prepared self-supporting Ni 5 Ru-TDA/NF with Ni/Ru molar ratio of 5:1 show the excellent OER and HER activities with low overpotentials of 235 and 35 mV at a current density of 10 mA cm −2 in 1 M KOH, respectively. Furthermore, Ni 5 Ru-TDA/NF indicate the remarkable stability during the process of OER and HER with the slight decrease after the stability test of 60 h. The excellent electrocatalytic activities can be attributed to high intrinsic activity of multiple Ru species, the synergistic effect of Ru and Ni sites and abundance active sites in Ru-doped Ni-TDA. The water electrolysis system using Ni 5 Ru-TDA/NF as the anode and cathode, respectively, can achieve a current density of 10 mA cm −2 with a cell voltage of only 1.53 V, which is promising for practical applications.