查找使用阿拉丁产品的科研文献

Fabrication of magnetically recyclable yolk-shell Fe3O4@TiO2 nanosheet/Ag/g-C3N4 microspheres for enhanced photocatalytic degradation of organic pollutants

Lv Yan,Yue Lin,Khan Imran Mahmood,Zhou You,Cao Wenbo,Niazi Sobia,Wang Zhouping

Herein, we report the fabrication of Fe 3 O 4 @TiO 2 nanosheet/Ag/g-C 3 N 4 (Fe 3 O 4 @ns-TiO 2 /Ag/g-C 3 N 4 ) composite photocatalysts with well-designed hierarchical yolk-shell structure. To endow the composites with fascinating features, multiple functional components are perfectly integrated into the definite structure. The photodegradation experiments of organic pollutants revealed a significant enhancement in photocatalytic activity of developed composites as compared to P25, which is mainly due to the synergetic interaction of the tailored three-dimensional (3D) yolk-shell porous nanostructure, extended sunlight response range, and retarded the recombination probability of photogenerated electrons-holes. More importantly, the hybrid samples exhibited superior magnetic properties due to the magnetic component. The excellent magnetic recyclability and reusability of the photocatalysts are verified by the magnetic hysteresis loop and cyclic photocatalytic degradation experiments, which is significant for the green and sustainable applications of photocatalysts. Considering its remarkable photocatalytic performance and expectant magnetic recyclability, the composite photocatalysts are expected to be a promising candidate to dispose of future environmental issues.

Synergistic charge separation and magnetic recovery in a noble-metal-free Fe3O4/TiO2/Bi photocatalyst for bromate reduction

Ying Xu,Shuili Yu,Zhiqiang Fan,Xingli Ji,Cong Huang,Zheng Xu,Rui Liu,Chao Jiang

Bromate (BrO 3 − ), a carcinogenic and regulated disinfection by-product, poses a persistent challenge to drinking water safety due to its high solubility and chemical stability. In this work, a noble-metal-free Fe 3 O 4 /TiO 2 /Bi photocatalyst was successfully prepared and subsequently applied for BrO 3 − reduction under ultraviolet light. The ternary composite design enables cooperative functionality among the components, where Fe 3 O 4 facilitates charge transfer and magnetic separability, Bi 0 acts as a hole scavenger, and TiO 2 serves as the primary photoactive material. Characterization results confirmed the successful formation of the heterostructure with enhanced charge separation properties. The composite containing 5 wt% Bi exhibited the highest activity, achieving 99 % BrO 3 − removal within 25 min at pH 7.0, with a pseudo-first-order rate constant of 0.185 min −1 , which is 11.8 times that of pure TiO 2 . The enhanced photocatalytic performance is ascribed to the synergistic effect between Bi, Fe 3 O 4 and TiO 2 . Bi 0 nanoparticles functioned as hole acceptors to suppress recombination, while Fe 3 O 4 facilitated electron transport and provided magnetic separability. The photocatalyst retained high activity over five consecutive cycles with negligible metal leaching and performance loss. In addition, its effectiveness was verified in tap water containing typical inorganic ions and dissolved organic matter, demonstrating moderate inhibition but maintaining BrO 3 − reduction capability. This study provides a cost-effective, magnetically recoverable, and noble-metal-free photocatalyst with improved charge separation efficiency and recovery feasibility, offering practical potential for BrO 3 − mitigation in drinking water treatment.

An efficient approach for the synthesis of magnetic separable Fe3O4@TiO2 core-shell nanocomposites and its magnetic and photocatalytic performances

Jianchao Zhang,Lingyun Li,Rongrong Shi,Jiaming Mei,Zhang Xiao,Wei Ma

A convenient and efficient approach for the synthesis of Fe3O4@TiO2 nanocomposites with core-shell structure has been demonstrated. It takes four steps for synthesis process. Oleic acid-coated monodisperse Fe3O4 nanoparticles are obtained firstly, and surface modified Fe3O4 nanoparticles are followed to proceed. Then Fe3O4@TiO2 core-shell nanocomposites are subsequently synthesized using tetrabutyl titanate (TBOT) as titanium source and some polar aprotic solvents used as the mixed solvents. The obtained core-shell structure is composed of a central Fe3O4 nanoparticle core with sequential TiO2 surface, whereas the outer TiO2 coating was useful for the degradation of organic contaminants. Different core-shell nanocomposites in different polar solution are obtained. Shell thickness of Fe3O4@TiO2 nanocomposites could be adjusted rationally by changing synthetic conditions. The measurements of the magnetic properties demonstrate that the Fe3O4@TiO2 core-shell nanocomposites exhibit magnetic behavior at room temperature. The degradation of methylene blue solution was also explored.

Enhanced oxidative and adsorptive removal of thallium(I) using Fe3O4@TiO2 decorated RGO nanosheets as persulfate activator and adsorbent

Liangzhong Li,Chang Liu,Ruixue Ma,Yunjiang Yu,Zhaofeng Chang,Xiaohui Zhang,Chenyu Yang,Da Chen,Yang Yu,Wei Li,Yongdi Liu

In this study, Fe 3 O 4 @TiO 2 decorated reduced graphene oxide (RGO) nanosheets were synthesized by loading iron oxide on the surface of RGO nanosheets and subsequently coating by titanium oxide, which can be employed as the persulfate (PS) activator and high-performance adsorbent toward thallium (Tl). PS could be effectively activated by the Fe 3 O 4 @TiO 2 decorated RGO nanosheets due to the presence of RGO and Fe(II), resulting in the rapid oxidation of Tl(I) to Tl(III). The removal of Tl(I) was found to be pH-dependent, with the removal efficiency of more than 88.5% in the pH range of 8.0–12.0 at the optimal PS dosage of 10 mM and material dosage of 0.2 g/L. The surface precipitation of Tl 2 O 3 and enhanced adsorption affinity toward Tl were deduced to be main mechanisms for the extremely efficient removal of Tl(I) ions during the oxidation and adsorption hybrid process. The maximum removal capacity of the material at pH 8.0 was estimated as 673.2 mg/g based on the fitting result from the Langmuir model. Approximately 94.7% of ultimate removal capacity could be accomplished within the first 10 min at the initial Tl concentration of 8.5 mg/L. The PS catalytic oxidation coupled with the adsorption technique using the prepared Fe 3 O 4 @TiO 2 decorated RGO nanosheets were proven to be a promising approach for Tl(I) removal from water.

Three-phases Fe3O4@TiO2-P(VDF-HFP) composite films with high energy storage density at low filler fraction under low operating electric field

Shixin Wei,Qiong Fu,Yang Liu,Qian Ji,Yafei Hou,Laihui Luo,Weiping Li

An enhanced energy storage ability, under a low operating electric field, was achieved in Fe3O4@TiO2-P(VDF-HFP) composite films. The low conductivity TiO2 layer was coated onto the high polarization Fe3O4 to construct Fe3O4@TiO2 core–shell fillers for decreasing filler fraction and alleviating conductivity contrast. For instance, the 2 vol.% Fe3O4@TiO2-P(VDF-HFP) film shows a discharged energy density and energy efficiency of 8.6 J cm−3 and 61.7%, respectively, under a low operating electric field of 261.9 kV mm−1. The coated TiO2 and modified –OH groups not only restrict the adverse effects (such as high conductivity, easy agglomeration, etc) caused by Fe3O4, but also contribute greatly to the improvement of polarization and breakdown strength, leading to a significantly improved energy storage performance. Additionally, the present work might possess great potential applications for energy storage owing to the low filler fraction, simple, and low electric filed operation.

Enhanced photocatalytic degradation of polyethylene microplastics under simulated sunlight using Fe3O4@TiO2/Ag nanocomposite and optimization via response surface methodology

Wei Qian,Zheng Meng

Microplastics (MPs) pose significant environmental and health risks, and conventional disposal methods often suffer from inefficiency and potential ecological harm. Photocatalytic degradation has emerged as a promising solution. However, traditional TiO 2 -based photocatalysts are limited by high electron–hole recombination rates, narrow visible light absorption, and poor reusability. In this study, we develop and optimize a Fe 3 O 4 @TiO 2 /Ag nanocomposite for the efficient degradation of polyethylene (PE) MPs with facile recovery. The synergistic integration of Fe 3 O 4 and Ag with TiO 2 enhances visible light absorption and mitigates charge carrier recombination. Notably, the Fe 3 O 4 @TiO 2 /Ag nanocomposite exhibits a degradation efficiency of 15.54%, outperforming Fe 3 O 4 @TiO 2 (12.63%) and pristine TiO 2 (1.15%). Moreover, the composite maintains its performance over five consecutive cycles, underscoring its durability. The degradation efficiency of Fe 3 O 4 @TiO 2 /Ag was further optimized using response surface methodology. Overall, the developed Fe 3 O 4 @TiO 2 /Ag nanocomposite exhibits excellent photocatalytic efficiency, magnetic recoverability, and long-term stability, highlighting its potential for practical applications in mitigating microplastic pollution.

A Sensitive Electrochemical Assay for T4 Polynucleotide Kinase Activity Based on Fe3O4@TiO2 And Gold Nanoparticles Hybrid Probe Modified Magnetic Electrode

Zaiqiong Liu,Jinpeng Tao,Zhenyu Zhu,Yanli Zhang,Hongbin Wang,Pengfei Pang,Haibo Wang,Wenrong Yang

An ultrasensitive electrochemical assay for T4 polynucleotide kinase (T4 PNK) activity and inhibition was developed based on magnetic Fe3O4@TiO2 core–shell nanoparticles and gold nanoparticles hybrid probe (Fe3O4@TiO2-dsDNA-AuNPs) modified magnetic gold electrode (MGE). Fe3O4@TiO2-dsDNA-AuNPs hybrid probe was formed via DNA hybridization between phosphorylated DNA S1 modified Fe3O4@TiO2 and complementary DNA S2 assembled AuNPs. [Ru(NH3)6]3+ was used as an electrochemically active indicator to enhance the electrochemical signal. The proposed method is sensitive for T4 PNK activity assay with a linear range of 0.0001 to 10 U ml−1 and low detection limit of 0.00003 U ml−1. This strategy can be used to screen the T4 PNK inhibitors, holding a great potential for discovery of nucleotide kinase-target drug and early clinical diagnosis of cancer.

Magnetically induced construction of core–shell architecture Fe3O4@TiO2–Co nanocomposites for effective photocatalytic degradation of tetracycline

Qingmei Tan,Wensheng Zhang,Tianren Liu,Ying He,Yuangong Ma,Yingxin Yang,Dongxue Han,Dongdong Qin,Li Niu

Owing to the advantages of easy separation and recovery, the development of magnetic photocatalysts is essential to create a viable photocatalytic technology for the degradation of antibiotic contaminants in water. Herein, magnetic Fe3O4@TiO2–Co nanocomposites as a highly recyclable and effective photocatalyst with various Co loading percentages were successfully prepared via a facile route and evaluated for the photodegradation of model tetracycline (TC) antibiotics. As a result, the optimal Fe3O4@TiO2–Co-2.7 sample possesses a removal rate of 92.4% for TC degradation, which is 3.2 fold and 1.6 fold higher than those of single Fe3O4 (28.8%) and Fe3O4@TiO2 (58.7%), respectively. The enhanced photocatalytic activity is mainly attributed to the advantages of integrating magnetic Fe3O4 nanospheres and metal Co nanoparticles, resulting in the overall magnetic composites of Fe3O4@TiO2–Co having an ameliorative light collection ability, energy-saving recycling process, excellent photocatalytic activity, and high chemical and environmental stability. Satisfactorily, the Fe3O4@TiO2–Co photocatalyst could be easily recovered from the reaction solution by an applied magnetic field, and its photocatalytic activity shows almost no loss after five cycles of repetitive use. Moreover, the intermediates in the degradation pathway were identified via high-performance liquid chromatography–mass spectrometry (HPLC-MS) and the TC degradation pathway in the photocatalytic reaction of the as-designed system was proposed. The present work was successfully applied for the purification of tetracycline antibiotics in water pollutants, demonstrating a promising prospect for application to other pollutant degradation systems.

Enrichment of phospholipids using magnetic Fe3O4/TiO2 nanoparticles for quantitative detection at single cell levels by electrospray ionization mass spectrometry

Aiying Liu,Hua Zhang,Jianhua Ding,Wei Kou,Fei Yan,Keke Huang,Huanwen Chen

Quantitative detection of phospholipids at the single cell level remains in challenge. Herein, the TiO 2 -coated Fe 3 O 4 nanoparticles were synthesized to selectively enrich trace phospholipids from single cell, which were then eluted using 1.5% ammonia/methanol (w/w) for sensitive detection by electrospray ionization mass spectrometry . Under the optimal experimental conditions, eighteen phospholipids in single cell samples were detected and identified by MS/MS experiments. The limit-of-detections (LODs) were 0.012  μ g/L for phosphatidylcholine (PC, 34:1) and 0.014  μ g/L for phosphatidylcholine (PC, 36:2) in PBS matrix, with the linear range of 0.05–50  μ g/L ( R 2  ≥ 0.999). The recovery rates of 94.90–104.00% were obtained, with the relative standard deviations (RSDs ≤ 6.90%). Quantitative determination of PC in real unicellular samples was also achieved, with the concentration of 1.82–2.11  μ g/L for PC(34:1) and 1.25–1.65  μ g/L for PC(36:2) in six types of single cell, opening up possibilities for quantitative analysis of trace compounds in complex bio-samples. A set of 6 types of tumor cells were analyzed and further differentiated by the partial least squares-discriminant analysis (PLS-DA). Conclusively, a facile method for the direct quantification of phospholipids in single cell samples has been developed, showing potential applications for advanced investigation of phosphorylated substance at the single cell level.

Efficient oil-water separation with amphipathic magnetic nanoparticles of Fe3O4@TiO2

Shuai Liu,Guanyi Peng,Shanshan Chen,Hai Huang,Haiming Fan,Shutao Zhou,Ming Duan

A sono-photocatalyst for humic acid removal from water: Operational parameters, kinetics and mechanism

Nannan Geng,Wei Chen,Hang Xu,Mingmei Ding,Zhigang Liu,Zhen Shen

As a precursor of disinfection byproducts, humic acid (HA) has adverse effects on aquatic environments and human health. Currently, many advanced oxidation processes (AOPs) have been proposed to remove HA from drinking water, one of which is photocatalysis. However, the long reaction time required for degradation and drawbacks of the photocatalysts limit the large-scale application of photocatalysis. Therefore, two principal objectives were achieved in this work. First regarding the technology, we combined photocatalysis with ultrasonic waves to remove HA. Second regarding the photocatalyst, quaternary Fe 3 O 4 /TiO 2 -N-GO (FTNG) sono-photocatalysts with different amounts of Fe 3 O 4 were first synthesized using a simple hydrothermal method. Characterizations were performed to confirm the successful synthesis of the sono-photocatalyst and to determine some of its properties. The influence of different experimental factors such as Fe 3 O 4 content, ultrasonic power, catalyst dosage and initial HA concentration were studied. The first-order kinetic and second-order kinetic equations were used to simulate the experimental data. The results showed that FTNG-0.2 with 0.2 g of Fe 3 O 4 , which was added upon preparation, showed the highest sono-photocatalytic ability. In our experimental setup, greater than 99% removal efficiency (UV 254 ) and 94% mineralization rate (TOC) were achieved within 90 min at the optimum conditions (60 W ultrasound power and 1.0 g/L catalyst dosage for 30 mg/L HA). Compared with the pseudo-first-order kinetic model, pseudo-second-order model fitted better with the experimental data and it had higher R 2 values of 0.92, 0.98 and 0.98 for 30, 40 and 50 mg/L of HA, respectively. According to the scavenging tests and the ESR analysis, both of the OH and O 2 − were produced in the reaction, however, O 2 − radicals were assumed to be the dominating reactive species for the HA degradation. Moreover, after five repetitive experiments, the removal efficiency of HA can still reach 88.5%, indicating high stability of FTNG-0.2 sono-photocatalyst. The mechanism of degradation of HA by FTNG-0.2 in sono-photocatalytic system was mentioned based on several factors including the ultrasonic cavitation effect, Fenton-like reactions, photocatalytic reactions, etc. In fact, this was the first study to treat HA through sono-photocatalytic process, which showed great potential in drinking water treatment.

Solid state reaction studies in Fe3O4–TiO2 system by diffusion couple method

Zhongshan Ren,Xiaojun Hu,Xiangxin Xue,Kuochih Chou

The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by diffusion couple experiments at 1323–1473   K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1   ±   18.8   kJ   mol −1 .