查找使用阿拉丁产品的科研文献

A novel recyclable nano-adsorbent for enhanced oil recovery with efficient removal of Ca2+ and Cr6+ from oilfield wastewater

He Lei,Dai Yong,Wang Zhe,Yang Lutao,Zhang Luxia,Hu Pengpeng,Tian Yu,Mo Hong,Zhu Haomiao,Zhang Jun

Oilfield wastewater has a significantly negative influence on the recovery efficiency due to its hypersalinity. Therefore, magnetic graphene oxide (GO) modified with ethylene diamine tetraacetic acid (EDTA) and grafted by polyethylene glycol (PEG) nano-adsorbent was prepared to remove the Ca 2+ and Cr 6+ in Jidong Oilfield wastewater specifically. It was noteworthy that PEG- g -EDTA/Fe 3 O 4 /GO nano-adsorbent had excellent adsorption performance, with removal ratios up to 71.6% for Ca 2+ and 42.7% for Cr 6+ at 30 min. After the fifth recycling run, the nano-adsorbent still remained with high removal ratios (69.3% for Ca 2+ and 30.5% for Cr 6+ ) and high reuse rates (89.4% for Ca 2+ and 95.2% for Cr 6+ ), indicating that the nano-adsorbent had outstanding adsorption-desorption efficacy and high reusability. The adsorption test results demonstrated that the total salinity of the treated oilfield wastewater decreased by about 5,000 ppm, and the displacement efficiency further increased by 12.5% by chemical flooding compared with the untreated wastewater. Therefore, PEG- g -EDTA/Fe 3 O 4 /GO nano-adsorbent is an adsorbent with excellent potential which can effectively remove Ca 2+ and Cr 6+ in oilfield wastewater to enhance oil recovery (EOR).

Sol–Gel Synthesis and Photocatalytic Activity of Graphene Oxide/ZnFe2O4-Based Composite Photocatalysts

Tong Beibei,Shi Longfei,Liu Xiaohong

ZnO (ZO), Fe2O3 (FO), and graphene oxide (GO)/ZO/FO/ZnFe2O4 (ZFO) composite photocatalysts have been synthesized successfully via a simple sol–gel method and low-temperature technology. The phase structure and microstructural analysis confirmed that the GO/ZO/FO/ZFO magnetic separation photocatalyst is composed of GO, hexagonal ZnO, rhombohedral Fe2O3, and spinel ZnFe2O4 without any other impurities. The GO/ZO/FO/ZFO composite photocatalysts have a high visible light optical absorption coefficient and photocatalytic activity for degrading dyes, refractory pollutants, and antibiotics. The degradation percentages of methyl orange, tetrabromobisphenol A, and oxytetracycline hydrochloride by the GO/ZO/FO/ZFO magnetic separation photocatalyst were 98% for 180 min, 99% for 150 min, and 85% for 180 min, respectively. The special synthesis path leads to the formation of a special heterojunction between GO, ZnO, Fe2O3, and ZnFe2O4, which does not change the optical band gap value of the main lattice Fe2O3, and enhances the surface defects of the GO/ZO/FO/ZFO magnetic separation photocatalyst, resulting in high charge carrier transfer and separation efficiency of the catalyst and then enhanced the photocatalytic activity of the GO/ZO/FO/ZFO magnetic separation photocatalyst.

Research of dual-ion polymer batteries based on N-butyl-N-methylpiperidinium bis(trifluoromethylsulfonyl)imide ionic liquid electrolyte

Liu Hui,Zhu Weichen,Zhou Hongyan,Wang Jianzhong

The development of dual-ion metal-free batteries is restricted by the strong self-discharge effect and dissolution of some anode active materials in the polar electrolyte. This in turn leads to low coulombic efficiency and discharge capacity loss. It is of great significance to alleviate this phenomenon through the redox reactions of polymeric active materials. In this study, a metal-free poly(anthraquinonyl sulfide)-graphite battery was constructed based on a pure N -butyl- N -methylpiperidinium bis(trifluoromethylsulfonyl)imide ionic liquid electrolyte. The cell had a discharge capacity of 70.5 mAh g −1 (0.1 C) and a capacity retention rate of 98.6% after 100 cycles, with a coulombic efficiency of 98.3% (1 C). Comparative studies proved that the self-discharge effect of poly(anthraquinonyl sulfide)-graphite batteries is weaker than that of some dual-graphite batteries. Cyclic voltammetry experiments revealed that the redox reaction was highly reversible. Most significantly, this type of poly(anthraquinonyl sulfide)-graphite batteries provides a new way for the design of metal-free dual-ion batteries with excellent long-term cycling performance and minimal self-discharge effect. Graphical abstract

Rational Design of Biomass-Derived Composite Aerogels for Solar-Driven Seawater Desalination and Sewage Treatment

Fantao Meng,Yuang Zhang,Shufen Zhang,Benzhi Ju,Bingtao Tang

To combat the water crisis, on-site reclamation of freshwater from seawater and sewage is urgently desired, in which solar-driven interfacial evaporation has been recognized as an emerging strategy. However, potentially costly fabrication, salt accumulation, and contaminant influence still hinder the real-world application of solar–thermal evaporators. Herein, a biomass-derived composite aerogel is constructed through the Schiff base reaction of chitosan and polyethylenimine and freeze assembly and further loaded with CuS/rGO nanoheterostructures via a spray stacking strategy. Because of the reverse transport of vertical-channel arrays, the lower part enables excellent salt-resistant properties during long-term desalination in parallel to upward water supply. The upper part promotes the thermal localization by controlling the spatial distribution of CuS/rGO, providing high solar spectrum absorption for efficient water evaporation. Notably, the composite aerogel exhibits great superiority in sewage treatment benefiting from its adsorption and photocatalytic capabilities, thus harvesting freshwater resources that meet drinking water standards. The rational design of this cost-effective evaporator may inspire new paradigms for boosting the combination of solar–thermal utilization and freshwater access.

Novel Therapeutic Strategy for Bacteria-Contaminated Bone Defects: Reconstruction with Multi-Biofunctional GO/Cu-Incorporated 3D Scaffolds

Ying Yang,Min Li,Bixia Zhou,Xulei Jiang,Dou Zhang,Hang Luo,Shaorong Lei

Large-scale bone defects caused by traumatic injury or tumor resection, are accompanied by relatively high bacterial infection rates. Relevant clinical therapy encounters challenges of infection recurrence, poor vascularization, and bone destruction. Engineered substitutes endowed with multiple functions of bacterial eradication, osteoconductivity, and angiogenesis are urgently needed to address these challenges. Herein, graphene oxide/copper (GO/Cu) nanocomposite-decorated polylactide- co -glycolide (PLGA)/β-tricalcium phosphate (TCP) (P/T/GO/Cu) scaffolds are fabricated using 3D printing technology. A comprehensive evaluation of material characteristics and biological activities of these scaffolds is conducted and compared. This novel bone substitute has unique surface characteristics, and the incorporation of GO/Cu nanocomposites into the scaffolds exhibits improved antimicrobial and osteogenic potential and displays acceptable cytocompatibility. A subcutaneous implantation model in rats confirms the effective inhibition of abscess formation and inflammatory reactions, satisfactory neovascularization and tissue integration, and good biosafety of the implanted P/T/GO/Cu scaffolds. Eventually, a bacteria-contaminated bone defect model is established in rabbits and significantly better new cancellous bone formation featuring collagen or osteoid deposition is clearly found in the defect regions implanted with P/T/GO/Cu scaffolds. Thus, this novel bone substitute with excellent bacterial inhibition, osteogenesis, and angiogenesis capabilities represents a promising strategy to satisfy the multiple demands for the repair of bacteria-contaminated bone defects.

Preparation and lubrication properties of graphene oxide/polyethylene glycol/polyvinyl alcohol composite film

Hailin Lu,Chengzhi Li,Guangshen Xu

Ultralight Open-Cell Graphene Aerogels with Multiple, Gradient Microstructures for Efficient Microwave Absorption

Qilin Mei,Han Xiao,Guomin Ding,Huizhi Liu,Chenglong Zhao,Rui Wang,Zhixiong Huang

Development of high-performance graphene-based microwave absorbing materials with low density and strong absorption is of great significance to solve the growing electromagnetic pollution. Herein, a controllable open-cell structure is introduced into graphene aerogels by the graphene oxide (GO) Pickering emulsion. The open-cell graphene aerogel (OCGA) with multiple microstructures shows a significantly enhanced microwave absorption ability without any additions. A high microwave absorption performance with the minimum value of reflection loss (RLmin) of −51.22 dB was achieved, while the material density was only 4.81 mg/cm3. Moreover, by means of centrifugation, the graphene cells were arranged by their diameter, and a gradient, open-cell graphene structure was first fabricated. Based on this unique structure, an amazing microwave absorption value of −62.58 dB was reached on a condition of ultra-low graphene content of 0.53 wt%. In our opinion, such excellent microwave absorption performance results from multiple reflection and well-matched impedance brought by the open-cell and gradient structure, respectively. In addition, the structural strength of the OCGA is greatly improved with a maximum increase of 167% due to the introduction of cell structure. Therefore, the OCGAs with the gradient structure can be an excellent candidate for lightweight, efficient microwave absorption materials.Keywords:ultralight graphene aerogels;open cell;gradient microstructure;various microwave absorption

Ag/rGO/Bi2WO6 nanocomposite as a highly efficient and stable photocatalyst for Rhodamine B degradation under visible light irradiation

Jixian Ma,Binxia Zhao,Xiaoxiao Fan,Wenjie Wang,Xingliang Chen,Nan Shao,Peiyang Jiang

An efficient Ag/rGO/Bi 2 WO 6 nanocomposite was synthesized by the precipitation-photoreduction method. The resulting Ag/rGO/Bi 2 WO 6 showed excellent photocatalytic activity for the photodegradation of Rhodamine B (RhB), with 15%Ag/rGO/Bi 2 WO 6 photodegrading 96.97% of RhB in 180 min, which was 1.28, 1.09 and 1.05 times higher than that of Bi 2 WO 6 , Ag/rGO, and rGO/Bi 2 WO 6 , respectively. The effect of noble metal Ag's surface plasmon resonance and Schottky barrier , as well as the superior electron transfer ability of rGO , dramatically improved photo-generated electron-hole pair separation and transfer efficiency. In addition, the effects of pollutant concentration, pH, and catalyst dosage on Ag/rGO/Bi 2 WO 6 photocatalytic performance also were explored. Furthermore, the free-radical trapping tests revealed that the primary active radicals in the catalytic system are hole (h + ), superoxide radical (•O 2 − ), and hydroxy radical (•OH). Additionally, after four recycling, the photocatalytic performance of the Ag/rGO/Bi 2 WO 6 composite did not show a significant decline. As a result of this research, the Ag/rGO/Bi 2 WO 6 catalyst, as developed, has a bright potential for environmental purifying.

Improving dispersion and delamination of graphite in biodegradable starch materials via constructing cation-π interaction: Towards microwave shielding enhancement

Yi Yang,Jun-Ru Tao,Dian Yang,Qian-Ming He,Xu-Dong Chen,Ming Wang

Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness (SE T ) of the materials were greatly enhanced by construction of cation-π interaction and orientation of graphite. Specifically, the EM SE T values increased from 56.9 to 66.8 dB for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SE T values raised from 17.4 to 66.8 dB via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.

In Situ Electrosynthesis of MAX-Derived Electrocatalysts for Superior Hydrogen Evolution Reaction

Minhao Sheng,Xiaoqing Bin,Yawei Yang,Yi Tang,Wenxiu Que

MAX phases are frequently dominated as precursors for the preparation of the star material MXene, but less eye-dazzling by their own potential applications. In this work, the electrocatalytic hydrogen evolution reaction (HER) activity of MAX phase is investigated. The MAX-derived electrocatalysts are prepared by a two-step in situ electrosynthesis process, an electrochemical etching step followed by an electrochemical deposition step. First, a Mo 2 TiAlC 2 MAX phase is electrochemically etched in 0.5 m H 2 SO 4 electrolyte. Just several hours, electrochemical dealloy etching of Mo 2 TiAlC 2 MAX powders by applying anode current can acquire a moderated HER performance, outperforming most of reported pure MXene. It is speculated that in situ superficially architecting endogenous MAX/amorphous carbide (MAC) improves its intrinsic catalytic activity. Subsequently, highly active metallic Pt nanoparticles immobilized on MAC (MAC@Pt) shows a transcendental overpotential of 40 mV versus RHE in 0.5 m H 2 SO 4 and 79 mV in 1.0 m KOH at the current density of 10 mA cm −2 without iR correction. Ultrahigh mass activity of MAC@Pt (1.5 A mg pt −1 ) at 100 mV overpotential is also achieved, 29-folds than those of commercial PtC catalysts.

Facile construction of silver nanocubes/graphene oxide composites for highly sensitive SERS detection of multiple organic contaminants by a portable Raman spectrometer

Jiafeng He,Xian Li,Jumei Li

Here, we demonstrate a reliable surface-enhanced Raman scattering (SERS) substrate composed of graphene oxide (GO) nanosheets and Ag nanocubes for sensitive detection of varied organic contaminants , malachite green, methylene blue and crystal violet by a portable Raman spectrometer with the limits of detection (LODs) of 10 −9 , 10 −10 and 10 −9 M, respectively, owing to a synergistic SERS enhancement arising from electromagnetic field effect of Ag nanocubes and chemical enhancement of GO sheets. The SERS substrates also present highly uniform signal over substrates and low relative standard deviations of 6.53 %, 6.16 % and 6.70 %, respectively are obtained on each sample, which is attribute to the extremely uniform size of Ag nanocubes as well as the consistent distribution of Ag nanocubes on GO sheets. Moreover, the SERS substrate is capable of label-free detection of more complex organic pesticides such as tetramethylthiuram disulfide and diquat dibromide with the LOD of 10 −8 M, which is below the safety levels regulated by United States Environmental Protection Agency. Consequently, the Ag nanocubes/GO composites are promising as efficient SERS platforms for reliable and highly sensitive monitoring of food safety and environmental pollution .

Constructing zirconium based metal–organic frameworks based electrically-driven self-cleaning membrane for removal of tetracycline: Effect of ligand substitution

Zhonglong Yin,Yulong Liu,Shihao Zhou,Zhen Yang,Weiben Yang

Herein, UiO-66-X (X = H, NH 2 , Br, NO 2 ) were employed to construct the electrocatalytic membranes by blending with conductive graphite and Polyvinylidene fluoride (PVDF) for removal of tetracycline under low current density of 0.01 mA/cm 2 . The physicochemical and electrochemical properties of the fabricated membrane were investigated systematically. Results showed that ligand substitution reduced the molecular weight cutoff (MWCO) and pure water flux of UiO-66-X based membranes in the order of –Br > –NO 2  > –NH 2 due to the size exclusion effect. In addition, compared with UiO-66, UiO-66 functionalized with electron-donating group (–NH 2 ) endowed the electrocatalytic membrane with superior anti-fouling ability using bovine serum albumin (BSA) as model foulant, and inferior tetracycline removal and self-cleaning property, while the opposite phenomenon occurred for the functionalization of electronic-accepting groups (–Br and –NO 2 ) owing to the promoted electrocatalytic activity and inhibited oxygen evolution side reaction. Notably, UiO-66-NO 2 /Graphite/PVDF membrane removed 99.5 % of tetracycline and flux of fouled membrane was almost fully recovered by electric field for six cycles under low current density of 0.01 mA/cm 2 . •OH and •O 2 – radicals played dominant roles in tetracycline removal by electrocatalytic membranes and three degradation pathways of tetracycline were proposed according to the liquid chromatography-mass spectrometry. Electrically-driven self-cleaning mechanism was related to the reduced fouling potential of BSA after oxidation degradation. This work gets new insights into the effect of ligand substitution on the performance of Zr-MOFs based electrocatalytic membrane for antibiotics removal.