查找使用阿拉丁产品的科研文献

Microwave-assisted synthesis of well-defined nitrogen doping configuration with high centrality in carbon to identify the active sites for electrochemical hydrogen peroxide production

Jun Wan,Guoqun Zhang,Hongrun Jin,Jiabin Wu,Nian Zhang,Bin Yao,Kaisi Liu,Meilin Liu,Tonghuan Liu,Liang Huang

While nitrogen (N)-doped carbon can facilitate the four-electron transfer in oxygen reduction reaction (ORR), its effect on the two-electron path is yet to be investigated. To date, the random N-C bond configurations in N-doped carbons make it difficult to identify the active sites for electrochemical reactions . Here, we report a preparation of well-controlled N-C configurations with high centrality as model catalysts for identification of active sites for two-electron transfer ORR. Specifically, the synthesized Pyrrolic-N doped single-wall carbon nanotube and graphene utilizing a microwave-assisted pulse heating method, exhibit excellent activity for two-electron path (H 2 O 2 selectivity of 93.5% and 98.35%). X-ray adsorption near-edge structure spectroscopy measurements indicate that carbon atoms adjacent to Pyrrolic-N are the active sites for two-electron transfer. This work provides a viable way for the fabrication of tailored N configurations in carbon materials and significantly advances our understanding of the N moieties for the electrochemical H 2 O 2 generation.

High-performance cotton fabric-based supercapacitors consisting of polypyrrole/Ag/graphene oxide nanocomposite prepared via UV-induced polymerization

Liang Chunliu,Zang Limin,Shi Fangfang,Yang Chao,Qiu Jianhui,Liu Qifan,Chen Zhenming

Cotton fabric (CF) fabricated by natural cellulose fibers has porous structure, abundant hydrophilic hydroxyl groups and good mechanical flexibility, which is a promising substrate for flexible fabric-based supercapacitors. Graphene oxide (GO) nanosheets were fixed on the CF by vacuum filtration, and then the pyrrole monomers and silver ions (Ag + ) were adsorbed to the surface of GO/CF by π-π and electrostatic interactions, respectively. Polypyrrole/silver (PPy/Ag) nanoparticles were generated on the surface of GO/CF via in situ UV-induced polymerization, forming the flexible PPy/Ag/GO/CF electrodes. The electrodes combine three active materials (PPy, Ag and GO), which show good electrochemical performance. The electrode prepared under optimum conditions (UV irradiation time: 120 min; mass loading of GO on the CF: 3 mg cm −2 ) exhibits a high specific capacitance of 1664.0 mF cm −2 . The flexible symmetric quasi-solid-state fabric-based supercapacitor (QFSC) based on the optimum electrode also keeps superior electrochemical performance and excellent mechanical flexibility, which has a great application prospect for wearable energy storage devices.

Porous biomass foam of polypyrrole-coated cattail fibers for efficient photothermal evaporation

Yan Sun,Lingling Fan,Xiuling Lin,Changqi Feng,Songlin Peng,Dezhan Ye,Weilin Xu,Jie Xu

Solar-driven interfacial water evaporation has become a prospective approach for freshwater production, desalination, and sewage treatment via efficient photothermal conversion. Nevertheless, the development of high-performance, low-cost and environment-friendly solar evaporator is still a major challenge. In this work, a three-dimensional porous solar evaporator is proposed based on polypyrrole (PPy) decorated cattail fiber (CF) foam. The CF foam exhibits superior water transport capacity owing to the unique grooved structure of the cattail fiber. The as-prepared PPy@CF foam shows low thermal conductivity, good salt resistance, and superior light absorption of ∼97% in a wide wavelength region (300–2500 nm) after the introduction of PPy coating. The PPy@CF foam exhibits a vapor evaporation rate of 1.678 kg m −2 h −1 as well as a photothermal conversion efficiency of 99.6% under one sun illumination. In addition, the PPy@CF foam may be applied for clean water production from seawater and sewage with prominent rejection of ions and dye. The present work demonstrates the excellent potential of the PPy@CF foam as an economical biomass material for high-performance solar evaporators.

Photothermal converting polypyrrole/polyurethane composite foams for effective solar desalination

Qingbai Zhao,Yuqin Wan,Fan Chang,Yifan Wang,Hongkun Jiang,Lei Jiang,Xinyue Zhang,Ning Ma

As a green and renewable energy source , solar energy is one of the best options to drive desalination and water purification processes. In this paper, a lightweight commercial polyurethane foam (PUF) was chosen as the support modified with a black polypyrrole (PPy) layer to obtain a simple and effective photothermal conversion “black foam” (PPy-PUF). Due to the excellent spectral absorption capacity of the polypyrrole layer as well as surficial PPy micro-wrinkles, the surface temperature of the black foam rapidly increased when irradiated with solar illumination. Combined with the porous structure , low thermal conductivity , and hydrophilicity of the polyurethane foam, it can be continuously used for desalination and water purification purposes. The evaporation rate of water can be as 3.789 kg·m −2 ·h −1 under 4-sun and the evaporation efficiencies as 86.9% under 1-sun. The internal microstructure and photothermal conversion performance of the PPy-PUF materials proved that they are highly suitable for practical applications such as desalination and water purification, which provide feasible solutions for water shortage, sustainable energy, and environmental improvement.

Electrochemical Kinetics of Layered Manganese Phosphate via Interfacial Polypyrrole Chemical Binding

Jia-Lin Du,Xu Bao,Wei-Bin Zhang,Lun Zhang,Yao-Wen Guo,Xia Zhou,Xian-Li Zhang,Shan-Shan Chai,Shao-Bo Guo,Xiong-Wei Han,Jianping Long

Graphical Layer by layer : The electrochemical kinetics of layered manganese phosphate are improved via interfacial polypyrrole chemical binding for electrochemical supercapacitor application. The major limitation of low-cost and high-safety aqueous manganese-based materials for electrochemical energy storage is largely hampered by their poor cyclic stability, usually caused by the manganese dissolution and interfacial kinetics. Herein, we synthesized a manganese phosphate material via interfacial polypyrrole chemical binding, with unique structural properties for aqueous supercapacitor application. It exhibited higher specific capacitance, remarkable rate performance and better cycle stability compared to bare manganese phosphate. In contrast with interfacial polypyrrole coating on manganese phosphate nanosheets, the polypyrrole could form a Mn−N bond with the manganese phosphate, indicating stable chemical binding. Thus, the appropriate interfacial chemical binding is an efficient strategy to improve the nanostructure stability and electrochemical kinetics of manganese-based materials for aqueous electrochemical energy storage.

Hierarchically structured bilayer Aerogel-based Salt-resistant solar interfacial evaporator for highly efficient seawater desalination

Min Wang,Guorong Xu,Zihan An,Ke Xu,Chunhua Qi,Rasel Das,Heli Zhao

Solar vapor generation (SVG) has emerged as a promising technique of harvesting solar energy for producing fresh water from seawater. However, two main problems of insufficient energy utilization and salt accumulation on evaporation surfaces are still challenging issues for the broad application of this technique. In this work, we demonstrate a hierarchically structured bilayer aerogel by in situ deposition of polypyrrole (PPy) inside the top layer of cellulose . The light-absorbing PPy/cellulose composite with three-dimensional (3D) hierarchical structures served to convert solar energy into thermal energy and localize the heat to power the vaporization of water contained in the cellulose network. While the porous and hydrophilic cellulose matrix enabled continuous water transport and replenishment to the upper evaporative layer. Moreover, several microcracks were formed at the PPy/cellulose surface, which assisted vapor escape and salt re-dissolution. As a result, the prepared PPy/cellulose aerogel enabled a high seawater evaporation rate of 1.42 kg m −2  h −1 at energy efficiency of 97.8% under one sun illumination. The SVG system also exhibited highly efficient and stable evaporation performance in seawater without surface salt accumulation over one week.

Multifunctional Bacterial Cellulose Nanofibers/Polypyrrole (PPy) Composite Films for Joule Heating and Electromagnetic Interference Shielding

Yingjie Huo,Dan Guo,Jialu Yang,Yukai Chang,Bochong Wang,Congpu Mu,Jianyong Xiang,Anmin Nie,Kun Zhai,Tianyu Xue,Fusheng Wen

Polypyrrole has attracted more and more attention due to its low density, high conductivity, and excellent electro/photothermal conversion ability. However, the poor mechanical properties of polypyrrole limit its further application. In this work, mechanically flexible bacterial cellulose nanofibers/polypyrrole (BC@PPy) composite films were fabricated by in situ polymerization and vacuum filtration. The addition of BC improved the mechanical properties of PPy and made it have good tensile and bending capacity. The conductivity of BC@PPy films could be tuned by the polymerization time of pyrrole. The BC@PPy-6 h film displayed excellent low-voltage-driven Joule heating (up to 95.4 °C at 5 V) and high-efficiency photothermal conversion (up to 52.4 °C under 100 mW/cm2) performance. Moreover, the resultant BC@PPy-6 h film also showed outstanding electromagnetic interference (EMI) shielding effectiveness of exceeding 28.5 dB in the whole X band. Therefore, the multifunctional BC@PPy films possess high application prospects in wearable electrical devices for Joule heating, photothermal conversion, and EMI shielding.

Chidamide stacked in magnetic polypyrrole nano-composites counter thermotolerance and metastasis for visualized cancer photothermal therapy

Sizhen Wang,Zhiqiang Ma,Zhang Shi,Ying Huang,Tianheng Chen,Lei Hou,Tao Jiang,Feng Yang

A molecularly imprinted electrochemical sensor with tunable electrosynthesized Cu-MOFs modification for ultrasensitive detection of human IgG

Axin Liang,Shanshan Tang,Miao Liu,Yue Yi,Bingteng Xie,Huipeng Hou,Aiqin Luo

Human IgG is one of the most important immunoglobulins in the human body. The present study described the fabrication of four kinds of layer-by-layer structures of copper metal-organic frameworks (Cu-MOFs) on the working electrode by electrodeposition, which were then applied as an electrochemical sensor for the sensitive determination of IgG in serum. First, MOFs synthesized using different deposition potentials are expected to have varied morphology and properties. Herein, four copper MOFs (Cu-MOFs) were electrosynthesized by a simple and direct reduction approach. The as-synthesized Cu-MOFs exhibit varied morphology and electrocatalytic behavior. Then, IgG was employed as a template in the electropolymerization of pyrrole-imprinted films on the surface of glassy carbon electrodes. Finally, the template protein was removed to form a molecularly imprinted film with the capability to qualitatively and quantitatively signaling of IgG. Under optimized conditions, the sensor for IgG exhibits a wide detection range of 0.01–10 ng mL −1 with a limit of detection (LOD) of 3 pg mL −1 (S/N = 3). Besides, other parameters including the selectivity, reproducibility (RSD 3.6%), and recovery rate (95.2–102.0%) are all satisfactory. The practicability of the sensor was verified by detecting IgG in human serum samples, which indicated that the sensor was suitable for potential clinical applications.

Hydrophobic Ce-doped β-PbO2-SDS anode achieving synergistic effects for enhanced electrocatalytic oxidation of As(III)

Wenlan Ji,Yuan Wang,Yuanjie Xiong,Tian C. Zhang,Shaojun Yuan

To strengthen the utilization of free radicals and effectively enhance electrocatalytic performance and service lifetime of the β -PbO 2 electrode, herein, a novel hydrophobic TNAs/SnO 2 /PPy/ β -PbO 2 -Ce-SDS (abbreviated as β -PbO 2 -Ce-SDS) anode was synthesized by doping Ce 3+ and anionic surfactant (SDS) to TNAs/SnO 2 /PPy/ β -PbO 2 (abbreviated as β -PbO 2 ), which was constructed by growing SnO 2 /PPy/ β -PbO 2 multilayers on TiO 2 nanotube arrays (TNAs) via combination of electrodeposition and electro-polymerization processes. Notably, co-modification with Ce 3+ and SDS remarkably enhanced the surface hydrophobicity, electrochemical performance and catalytic ability of β -PbO 2 anode. Such β -PbO 2 -Ce-SDS anode not only substantially enhanced the As(III) conversion (96.96%) in the electrocatalytic oxidation process, but also prominently strengthened its service lifetime. Furthermore, the as-prepared β -PbO 2 -Ce-SDS anode possessed an excellent stability as its kinetic constant was only reduced from 0.18 to 0.14 min −1 even underwent 10 cycles of the electrocatalytic process, while that of the unmodified β -PbO 2 electrode decreased markedly by about 49%, owing to its appropriate surface hydrophobicity, smaller grains and denser β -PbO 2 layer. The reaction mechanism of electrocatalytic oxidation was associated with synergistic effects of hydroxyl radical ( OH), superoxide radicals ( O 2 − ), and sulfuric acid root radicals ( SO 4 − ). The β -PbO 2 -Ce-SDS anode provides a novel and feasible approach to development of various electrodes by doping metal ions and/or regulating with surfactants.

Tellurium: A High-Performance Cathode for Magnesium Ion Batteries Based on a Conversion Mechanism

Ze Chen,Qi Yang,Donghong Wang,Ao Chen,Xinliang Li,Zhaodong Huang,Guojin Liang,Ying Wang,Chunyi Zhi

Magnesium ion batteries (MIBs), due to the low redox potential of Mg, high theoretical capacity, dendrite-free magnesiation, and safe nature, have been recognized as a post-lithium energy storage system. However, an ongoing challenge, sluggish Mg2+ kinetics in the small number of available cathode materials of MIBs, restricts its further development. The existing cathodes mostly deliver unsatisfactory capacity with poor cycling life based on the traditional ion-intercalation mechanism. Herein, we fabricated a conversion-type Mg∥Te battery based on a reversible two-step conversion reaction (Te to MgTe2 to MgTe). High discharge capacities (387 mAh g–1) and rate capability (165 mAh g–1 at 5 A g–1) can be achieved. The diffusivity of Mg2+ can reach 3.54 × 10–8 cm2 s–1, enabled by the high electrical conductivity of Te and increased surface conversion sites. Subsequently, ab initio molecular dynamics simulation was also carried out to further confirm the conversion mechanism and fast Mg2+ transportation kinetics.

Flexible Self-Supporting 3D Electrode Based on 3D Graphene-PPy@Fe-MnCo2O4 Nanostructure Arrays toward High-Performance Wearable Supercapacitors

Zihan Chen,Xihong Zu,Liheng Chen,Yi Qi,Wenbin Jian,Yaoying Wu,Wenli Zhang,Xuliang Lin,Guobin Yi,Quanbing Liu,Zilun Tang,Jianyu Wu,Huafeng Dong,Yanlin Qin

The development of high-performance flexible supercapacitors is desperately desired for application in wearable electronics, but the fabrication of a flexible self-supporting 3D electrode with light weight and high energy density remains challenging. Herein, we report an approach to fabricate the flexible self-supporting and lightweight 3D G-PPy@Fe-MnCo2O4 hierarchical electrode for flexible solid-state supercapacitors (FSSCs), which utilizes the active material 3D G-PPy as a substrate to vertically grow Fe-MnCo2O4 nanowire (NW) arrays. Importantly, the experimental results and DFT simulations indicate that Fe-MnCo2O4 NWs obtain metallic characteristics by doping Fe into a MnCo2O4 lattice, which induces the free propagation of electrons in the electrode. Thus, MnCo2O4 utilization efficiency and cycle performance are both greatly enhanced. The electrode has a high areal specific capacitance of 5136 mF cm–2 (422.4 F g–1) at 2 mA cm–2 with long-term cycle stability. The capacitance retention is about 94.7% after 7000 cycles. It presents a viable design route toward advanced wearable energy storage devices.