查找使用阿拉丁产品的科研文献

Flexible carbon nanofiber film with diatomic Fe-Co sites for efficient oxygen reduction and evolution reactions in wearable zinc-air batteries

Yiyan Wang,Zongge Li,Peng Zhang,Yuan Pan,Ying Zhang,Qiong Cai,S. Ravi P. Silva,Jian Liu,Guoxin Zhang,Xiaoming Sun,Zifeng Yan

Carbon nanofiber (CNF) papers have been widely used in many renewable energy systems , and the development of its catalytic function is of great significance and a major challenge. In this work, we pioneer a time- and cost-efficient strategy for the preparation of large-area flexible CNF films with uniformly distributed diatomic FeN 3 -CoN 3 sites (Fe 1 Co 1 -CNF). Due to the excellent compatibility and similar functionality of the pre-designed ZnFeCo-NC precursors (ZnFeCo-pre) with the electrospun polymer polyacrylonitrile (PAN), the mixture of ZnFeCo-pre and PAN can be co-electrospun and subject to a standard CNF fabrication process. The resulting Fe 1 Co 1 -CNF exhibits excellent bifunctional catalytic performance for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), attributing to the abundant dual catalytic FeN 3 -CoN 3 sites which are mutually beneficial for attaining optimal electronic properties for the adsorption/desorption of reaction intermediates. The assembled liquid-electrolyte ZAB provides a high specific power of 201.7 mW cm −2 and excellent cycling stability. More importantly, due to the good mechanical strength and flexibility of Fe 1 Co 1 -CNF, portable ZAB with exceptional shape deformability and stability can be demonstrated, in which Fe 1 Co 1 -CNF utility as an integrated free-standing membrane electrode. These findings provide a facile strategy for manufacturing flexible multi-functional catalytic electrodes with high production.

Rod-Like Fe, Bi Co-doped Co3O4 as an Efficient Electrocatalyst for Chlorine Evolution Reaction and Ammonia-Nitrogen-Oxidation in Water

KeXuan Wu,Ting Peng,Jing Cao

Graphical In this paper, a rod-like Fe and Bi co-doped Co 3 O 4 is prepared by hydrothermal method as an electrocatalyst for chlorine evolution reaction and ammonia nitrogen degradation. Compared to Co 3 O 4 , the doping of Fe and Bi can effectively improve the electrocatalytic performance, providing a new design idea for the construction of electrode materials with high activity and selectivity. Chlorine evolution reaction (CER) using dimensionally stable anode (DSA) materials are widely used in the chlor-alkali industry. However, they still have problems such as high preparation cost, limited selectivity, the titanium substrate being easy to passivate, [ 2 ] and the electrode active material being easy to dissolve. Co 3 O 4 , a nonprecious metal material, has shown good catalytic potential in promoting the CER reaction, which has broad application prospects as a CER electrocatalyst. In this paper, a highly regular Rod-like Fe, Bi co-doped Co 3 O 4 electrocatalyst was prepared. Compared with pure Co 3 O 4 , the material had a larger electrochemical-specific surface area, lower charge transfer resistance, and better catalytic performance. In a 0.6 M NaCl solution, at a current density of 20 mA/cm 2 , it achieves a current efficiency of 91.8% and degrades ammonia nitrogen with an efficiency of 82%.

Regulation of morphology and particle size of spinel LiMn2O4 induced by Fe-B co-doping for high-power lithium ion batteries

Mei Yang,Jiao Ma,Ling Xia,Yujiao Guo,Xiaofang Liu,Wei Bai,Mingwu Xiang,Junming Guo

The spinel LiMn 2 O 4 cathode material shows severe capacity degradation due to Jahn–Teller distortion and dissolution of Mn during the charge-discharge process. Herein, a series of single crystal truncated octahedral of LiFe 0.03 B x Mn 1.97−x O 4 (0≤x≤0.10) were synthesized by simple solid-state combustion combined with Fe-B co-doping, morphology and particle size controlling strategy. Through Fe-B co-doping, not only the LiFe 0.03 Mn 1.97 O 4 containing {111}, {100} and {110} planes are successfully controlled to the particles containing only {111} and {100} planes, but also the near-nanometer particles are controlled to bigger submicron sizes. It is found that Fe-B co-doping can enhance the stability of the crystal structure, inhibit Jahn-Teller distortion and reduce the dissolution of Mn. Among them, the optimized LiFe 0.03 B 0.08 Mn 1.89 O 4 forms a truncated octahedral single crystal particle with good crystallization and only {111} and {100} crystal faces, and the particle size is around 349.3 nm, showing exceptional high rate capacity and long cycle life. The LiFe 0.03 B 0.08 Mn 1.89 O 4 releases a high initial discharge capacity of 107.1 mAh/g with a capacity retention of 77.7% after 1000 cycles at 10 C, which is higher than that of the LiFe 0.03 Mn 1.97 O 4 (58.8%). Even at 20 C, LiFe 0.03 B 0.08 Mn 1.89 O 4 still achieves a high reversible specific capacity (90.4 mAh/g) and outstanding long-cycle stability (81.3%, 1000th). This work provides a scientific basis for the crystal surface control and particle size control of spinel LiMn 2 O 4 , which is of great significance for the development of the next generation of high-power lithium-ion batteries.

One-step synthesis ionic liquid functionalized Co/Fe-LDH for effective removal of Methylene Blue from water: Batch and column experiment

Chunlai Wu,Aimaiti Gali,Chuanyun Peng,Yalei Miao,Juan Li,Xinyu Gao

The treatment of dye wastewater is of crucial significance for alleviating water pollution, ensuring ecological security and achieving the sustainable utilization of water resources. In this work, the 1-allyl-3-butylimidazolium chloride ionic liquid modified Co/Fe-LDH (Co/Fe-LDH@IL) was successfully synthesized and explored for elimination Methylene Blue (MB) from aqueous solutions. Characterizations revealed that the incorporation of ionic liquids notably increased the specific surface area from 5.37 m2.g−1 to 8.15 m2.g−1. Additionally, the number of surface active sites, was significantly enhanced. For a 25 mL MB solution with an initial concentration of 300 mg.L−1, the optimal dosage of Co/Fe-LDH@IL was determined to be 30 mg, achieving adsorption equilibrium within 20 min. Under these conditions, the maximum adsorption capacity was 517.43 mg.g−1. Kinetic studies indicated that the pseudo-second-order model accurately described the process. The Langmuir isotherm model provided a better fit than the Freundlich model, indicating a homogeneous monolayer adsorption mechanism. Column adsorption experiments further validated the superior performance of Co/Fe-LDH@IL in treating MB solutions of different concentrations. The adsorption mechanism involved electrostatic interactions, interface regulation by IL molecules, and monolayer π-π interaction adsorption on imidazole functional group. Co/Fe-LDH@IL exhibits outstanding adsorption performance and stability, showing great potential for efficiently treating MB-containing wastewater.

Fe/N codoped porous graphitic carbon derived from macadamia shells as an efficient cathode oxygen reduction catalyst in microbial fuel cells

Haoming Ning,Zhi Zhang,Chunhai Shi,Xiaolei Ma,Jian Li,Hongyi Zhu,Jiawei Hu

In this study, Fe/N codoped porous graphitic carbon derived from macadamia shells was prepared at different temperatures as cathodic catalysts for microbial fuel cells (MFCs), with K2FeO4 as a bifunctional catalyst for porosity and graphitization. The catalyst prepared at 750 °C (referred to as MSAC-750) showed a large specific surface area (1670.3 m2 g−1), graphite structure, and high pyridine-N and Fe-NX contents. Through the electrochemical workstation test, MSAC-750 shows excellent oxygen reduction reaction (ORR) activity, with an onset potential of 0.172 V and a half-wave potential of −0.028 V (vs. Ag/AgCl) in a neutral medium, and the ORR electron transfer number is 3.89. When applied to the MFCs as cathodic catalysts, a higher maximum power density and voltage of 378.68 mW m−2 and 0.425 V were achieved with the MSAC-750 catalyst and is superior to that of the Pt/C catalyst (300.85 mW m−2 and 0.402 V). In this case, a promising method is hereby established for the preparation of an excellent electrochemical catalyst for microbial fuel cells using inexpensive and easily available macadamia shells.

In situ embedding dual-Fe nanoparticles in synchronously generated carbon for the synergistic integration of magnetic resonance imaging and drug delivery

Hui Zhang,Jianping Zhang,Qianqian Zhang,Xiaofeng Liu,Yongtai Yang,Yun Ling,Yaming Zhou

In situ incorporating versatile magnetic iron nanoparticles into ordered mesoporous carbon (OMC) by means of synthetic methodology for functional integration is a great challenge. Inspired by the phenomenon of uniovular twins in nature, a homometallic [Fe9(μ3-O)4(O3PPh)3(O2CCMe3)13] ({Fe9P3}) cluster was synthesized and used as the ovulum to in situ produce dual-Fe nanoparticle (γ-Fe2O3 and Fe(PO3)3)-functionalized OMC (dual-Fe/OMC). In vitro magnetic resonance imaging (MRI) studies showed a longitudinal relaxation (r1) and transverse relaxation (r2) of 9.74 and 26.59 mM−1 s−1 with a r2/r1 ratio of 2.73 at 0.5 T. The MRI performances were further examined by mouse model with a subcutaneous HeLa tumor. In addition, the low cytotoxicity, considerable loading capacity and delivery of doxorubicin hydrochloride (DOX) were also studied in vitro. These results demonstrate the feasibility of the concept of uniovular twins in the one-pot preparation of dual-Fe/OMC for functional integration.

Synthesis of microcrystalline brownmillerite Ca2(Al,Fe)2O5 and its influence of mechanical properties to the class G oil-well cement

Xiaowei Cheng,Yongsheng Yang,Yongqiang Yang,Kaiqiang Liu,Kaiyuan Mei,Zaoyuan Li,Xiaoyang Guo,Wenhui Duan

Achieving a “all in one” Fe/Tm-MOFs with controllable photothermal and catalytic performance for imaging-guided multi-modal synergetic therapy

Haiqing Gao,Qin Ji,Bin Chi,Caixue Lin,Gang Ding,Yingxi Wang,Xiaolan Yu,Zushun Xu,Run Zhang,Ling Li,Jing Wang

Targeting excess H 2 O 2 in the tumor microenvironment, nanotheranostic agents for catalytic therapy are designed based on Fenton reaction, catalyzing H 2 O 2 into oxygen and hydroxyl radical ( OH). But the catalytic efficiency in tumor microenvironment is not satisfactory. In order to solve the problem, a series of bimetallic-dual ligands metal-organic frameworks Fe/Tm-MOFs were designed, that Fe 3+ and Tm 3+ as metalions, 2-methylimidazole and trimesic acid as ligands. Due to the doped Tm 3+ in Fe/Tm-MOFs and the conjugated structures formed by two ligands, the rate of electron transfer was improved, thus promoting the generation of OH at some extent. In addition, the photothermal effect of Fe/Tm-MOFs further promotes the generation of OH, which was evidenced by the 3,3′,5,5′-tetramethylbenzidine(TMB). Combining the drug loading and release capabilities of Fe/Tm-MOFs, synergetic therapy of photothermal/chemo-/catalytic therapy can be achieved. In vitro results reveal that DOX release behaviors are both pH- and thermal-responsive. In vivo anti-cancer results show that the tumors of mice almost disappeared within 10 days, which were injected with Fe/Tm-MOFs/DOX and irradiated with 808 nm for 10 min. Thus, an excellent therapeutic performance has been achieved. Besides, Fe/Tm-MOFs can serve as a multimodality bioimaging contrast agent, covering fluorescence imaging, photothermal imaging and magnetic resonance imaging. Thus, an all-in-one nanotheranostic agent is constructed, improving the catalytic efficiency and providing a novel method to design an efficient nanotheranostic agent.

Removal mechanism of Sb(III) by a hybrid rGO-Fe/Ni composite prepared by green synthesis via a one-step method

Ze Lin,Xiulan Weng,Nasreen Islam Khan,Gary Owens,Zuliang Chen

The annual influx of antimony (Sb) into the environment due to the widespread use of Sb compounds in industry and agriculture has become of global concern. Herein, a functional nanomaterial composite based on loading bimetallic iron/nickel nanoparticles on reduced graphene oxide (rGO-Fe/Ni) was initially prepared in a one-step phytogenic synthesis using a green tea extract. Subsequently, when applied for Sb(III) removal, the removal efficiency of rGO-Fe/Ni reached 69.7% within 3 h at an initial Sb concentration of 1.0 mg·L −1 . Advanced materials characterization via scanning electron microscopy-energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that Sb(III) was initially adsorbed onto the surface of rGO and then oxidized to Sb(V). This result was also supported by adsorption isotherm, kinetics, and thermodynamic analysis. These studies revealed that the adsorption was spontaneous and endothermic, following a Langmuir adsorption model with pseudo-second-order kinetics and allowed a Sb(III) removal mechanism based on adsorption and catalytic oxidation to be proposed. Furthermore, when rGO-Fe/Ni was practically used to remove Sb(III) in groundwater a 95.7% removal efficiency was obtained at 1 mg·L −1 Sb(III), thus successfully demonstrating that rGO-Fe/Ni has significant potential for the practical remediation of Sb contaminated groundwater.

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO2 Reduction and Fe/Mn Stabilization

Fengping Zhou,Ye Xiao,Meina Guo,Yetao Tang,Weihua Zhang,Rongliang Qiu

The increasing demand for rare earth elements (REEs) motivates the development of novel strategies for cost-effective REE recovery from secondary sources, especially rare earth tailings. The biggest challenges in recovering REEs from ion-adsorption rare earth tailings are incomplete extraction of cerium (Ce) and the coleaching of iron (Fe) and manganese (Mn). Here, a synergistic process between reduction and stabilization was proposed by innovatively using elemental sulfur (S) as reductant for converting insoluble CeO2 into soluble Ce2(SO4)3 and transforming Fe and Mn oxides into inert FeFe2O4 and MnFe2O4 spinel minerals. After the calcination at 400 °C, 97.0% of Ce can be dissolved using a diluted sulfuric acid, along with only 3.67% of Fe and 23.3% of Mn leached out. Thermodynamic analysis reveals that CeO2 was indirectly reduced by the intermediates MnSO4 and FeS in the system. Density functional theory calculations indicated that Fe(II) and Mn(II) shared similar outer electron arrangements and coordination environments, favoring Mn(II) over Ce(III) as a replacement for Fe(II) in the FeO6 octahedral structure of FeFe2O4. Further investigation on the leaching process suggested that 0.5 mol L–1 H2SO4 is sufficient for the recovery of REEs (97.0%). This research provides a promising strategy to selectively recover REEs from mining tailings or secondary sources via controlling the mineral phase transformation.

Simultaneous recovery of ammonium and phosphate from aqueous solutions using Mg/Fe modified NaY zeolite: Integration between adsorption and struvite precipitation

Zhenwei Lu,Keqiang Zhang,Fuyuan Liu,Xingliang Gao,Zhongwei Zhai,Jiajia Li,Lianzhu Du

Currently, the closure of the nutrient circular loop and contaminant removal from wastewater are drawing widespread attention. In this study, a novel MgO/iron oxide-modified NaY zeolite (MNZ) was prepared and used for the integration of adsorption and struvite precipitation to simultaneously reclaim ammonium and phosphate from wastewater. The results proved that MgO and iron oxide nanoparticles were successfully embedded in the zeolite matrix, providing high adsorption performance for ammonium and phosphate, reaching 380.02 (as NH + 4) and 324.68 (as P T ) mg/g, respectively. The presence of NO 3 −  , Cl − , SO 4 2− , and HCO 3 − did not significantly influence the adsorption of ammonium and phosphate. Struvite precipitation on the MNZ surface is the primary mechanism for the recovery of both ammonium and phosphate with electrostatic attraction and ion exchange also involved in ammonium uptake. These results indicate that optimized MNZ is promising for nutrient recovery from wastewater because of its high selectivity for targeted absorbates and its potential application as a slow-release eco-fertilizer.

Boosting oxygen reduction catalysis with Fe-N@ZnO codoped highly graphitized carbon derived from N,N′-carbonyldiimidazole-Induced bimetallic coordinated polymer

Wen-Li Xin,Lian-Hua Xu,Kun-Kun Lu,Dan Shan

Fe-N catalysts are one of the promising candidates with efficient oxygen reduction reaction (ORR) activities comparable to Pt-based catalysts. Therefore, in this work, a novel Fe-N based electrocatalyst with high activity, porous structure, and durability were prepared. Highly active N,N′-carbonyldiimidazole (CDI) was used to form zinc-based zeolitic imidazole frameworks involved with zinc carbonate (Zn-ZIFs@ZnCO 3 ). Fe-doping can be feasibly achieved by partial substitution Zn by Fe using Fe (NO) 3 . Owing to the presence of ZnCO 3 and Fe 3+ , carbonization of Fe/Zn-ZIFs@ZnCO 3 at 925 °C under N 2 atmosphere endows the pyrolysis products with many highly active heterostructures of 3D graphene structure. The obtained Fe-N@ZnO possesses superior ORR performance to commercial 20% Pt/C catalysts, such as positive half-wave potential (0.851 V), good durability and methanol tolerance in 0.1 M KOH.