基于MXenes的功能纤维的制备及其在智能可穿戴领域的应用

在电子信息和物联网技术的推动下,人类对可穿戴电子器件和智能织物的需求愈发突出,功能纤维作为智能可穿戴设备的重要载体,近年来获得快速发展。功能纤维的性能很大程度上取决于纤维的基础构筑单元。过渡金属碳/氮化物(MXenes)作为一种新兴的二维材料,凭借其高电导率、优异的可加工性能、可调节的表面特性以及出色的机械强度等优点,受到了极大的关注,也逐渐成为构筑功能纤维的重要单元。本文将主要综述MXenes的湿化学、熔融盐、无氟试剂刻蚀等方法和力学、电学、光学和化学稳定性等性能,阐述基于该材料制备的功能纤维在传感、储能以及其他智能领域的应用,最后讨论了基于MXenes材料的功能纤维的未来应用前景和技术挑战。     

蚕丝基智能纤维及织物：潜力、现状与未来展望

纤维及织物因具有良好的柔性、透气性以及适宜的力学性能而成为人们日常生活必不可少的材料。随着柔性电子器件的快速发展,纤维及织物在其自身优势的基础上,开始被人们赋予智能化特征,使得智能纤维和织物逐渐在可穿戴领域占据一席之地。天然蚕丝具有产量大、机械性能优异和生物可降解的优势。近年来,面向智能应用的蚕丝基纤维与织物逐渐发展,被用于传感、致动、光学器件、能量收集和储能等领域。本文将首先介绍天然蚕丝的层级结构和性能,并介绍各种形貌结构的再生蚕丝材料;然后根据其在智能纤维及织物中应用领域的不同,详细阐述蚕丝基智能纤维及织物的制备方法、性能及工作机制;最后讨论进一步发展所面临的挑战与机会,并对未来前景进行展望。     

Optimizing the Photovoltaic Performance of Organic Solar Cells for Indoor Light Harvesting

Organic solar cells (OSCs) harvesting indoor light are highly promising for emerging technologies, such as internet of things. Herein, the photovoltaic performance of PTB7-Th:PC₇₁BM solar cells constructed using “optimized (with 1,8-diiodooctane (DIO))” and “non-optimized (without DIO)” processing conditions are compared for indoor and outdoor applications. We find that in comparison to the “optimized” solar cell, the “non-optimized” solar cell is less efficient under simulated solar light illumination (100 mW cm⁻², spectral range 350–1100 nm), owing to significant bimolecular charge carrier recombination losses. However, under simulated indoor illumination (3.28 mW cm⁻², spectral range 400–700 nm), bimolecular recombination losses are effective suppressed, thus the power conversion efficiency of the solar cell without DIO was increased to 14.7 %, higher than that of the solar cell with DIO (14.2 %). These results suggest that the common strategy used to optimize the OSCs could be undesired for indoor OSCs. We demonstrate that the efforts for realizing the desired “morphology” of the active layer for the outdoor OSCs may be unnecessary for indoor OSCs, allowing us to realize high-efficiency indoor OSCs using a non-halogenated solvent.     

Enhanced Crystal Quality of Perovskite via Protonated Graphitic Carbon Nitride Added in Carbon-Based Perovskite Solar Cells

The quality of perovskite layers has a great impact on the performance of perovskite solar cells (PSCs). However, defects and related trap sites are generated inevitably in the solution-processed polycrystalline perovskite films. It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization. Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride (p-g-C\begin{document}$_3$\end{document}N\begin{document}$_4$\end{document}) was successfully synthesized and doped into perovskite layer of carbon-based PSCs. The addition of p-g-C\begin{document}$_3$\end{document}N\begin{document}$_4$\end{document} into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide (MAPbI\begin{document}$_3$\end{document}) crystal for obtaining flat perovskite surface with larger grain size, but also reduces intrinsic defects of perovskite layer. It is found that the p-g-C\begin{document}$_3$\end{document}N\begin{document}$_4$\end{document} locates at the perovskite core, and the active groups -NH\begin{document}$_2$\end{document}/NH\begin{document}$_3$\end{document} and NH have a hydrogen bond strengthening, which effectively passivates electron traps and enhances the crystal quality of perovskite. As a result, a higher power conversion efficiency of 6.61% is achieved, compared with that doped with g-C\begin{document}$_3$\end{document}N\begin{document}$_4$\end{document} (5.93%) and undoped one (4.48%). This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.     

Highly efficient photocatalytic degradation for antibiotics and mechanism insight for Bi2S3/g-C3N4 with fast interfacial charges transfer and excellent stability

Bi₂S₃/g-C₃N₄ (BSCN) samples with different mass ratios of CN to BS were prepared by a facile and practicable hydrothermal method with 2D g-C₃N₄ nanosheets (CN). The microscopic morphology and structure of pure CN, BS and BSCN were measured by multiple testing methods. Analysis results show that the BSCN was prepared successfully, and the Bi₂S₃ nanoparticles closely and uniformly adhered to the surface of CN with sheet-like structure. The introduction of Bi₂S₃ did not change the structure of the CN. The results of the ultraviolet–visible spectroscopic analysis, photoluminescence spectra and electrochemical performance indicated that BSCN showed superior visible-light response compared with CN, and the separation and transfer efficiency of photogenerated carriers was significantly improved. With the decrease of mass ratio of CN/BS, the photocatalytic activity of BSCN initially increased and then decreased for 20 ppm of Rhodamine B solution (RhB), and the Bi₂S₃/g-C₃N₄-B with a mass ratio of 8:1 for CN to BS showed optimal photocatalytic performance (98.98%). Furthermore, the Bi₂S₃/g-C₃N₄-B exhibited apparent degradation effects (1.021 x10^-2, 0.879 x10^-2 and 0.793 x10^-2 min^?1) to three kinds of antibiotics (tetracycline, ciprofloxacin, and oxytetracycline). The BSCN samples still maintained higher degradation efficiency after five cycles of degradation to tetracycline. The capture experiments and the electron spin resonance (ESR) spectra analysis indicated that the h⁺ and ·O₂^? played a major role, and ·OH played secondary role during the photocatalytic reaction.     

无溶剂法大量制备高效红光碳点及其在白光器件中的应用

以邻苯二胺、 2,5-二氨基苯磺酸和三氯化铝为原料, 通过无溶剂法大量制备了高效的红色荧光碳点 (R-CDs). 制得的碳点尺寸大约为2.4 nm, 含有13%的氮元素, 主要由高度石墨化的碳核及覆盖在其表面的大量官能团构成. 在不同的波长光激发下, 碳点在乙醇溶液中表现出不依赖于激发的红光发射, 其荧光峰位于 704 nm, 最大量子产率达到22%. 由于R-CDs具有优异的光学性质, 利用其构筑了紫外光激发的碳基白色发光二极管, 其色坐标为(0.33, 0.33), 非常接近自然光. 该研究为高效红色荧光碳点的大量制备提供了一种新路径, 同时拓宽了其在白光器件中的应用.     

在体酶生物燃料电池的研究进展

酶生物燃料电池(Enzymatic biofuel cells,EBFCs)具有高专一性和催化性能,可催化与氧化还原反应有关的燃料并获得电能.可用的生物燃料,如葡萄糖、乳酸和丙酮酸盐,可以从汗液、泪液和血液中提取,因而以体液为燃料的EBFCs在可植入式或可穿戴式设备中具有良好的应用前景.采用生物电催化机理对酶生物燃料电池在体液发电中的应用进行了研究,以及对可植入式或可穿戴式生物燃料电池的主要挑战和未来的前景进行了展望.     

OPC技术在设备监控系统中的应用

本文主要从0PC技术的定义和对象方面展开,在对OPC技术进行简要介绍的基础上,探讨了0PC服务器与OPC客户端的通信实现,结合实际,着重介绍其在某个iFIX监控平台中的应用。实践结果证明：将OPC技术应用在iFIX监控平台中,可以很好的实现软硬件的兼容,有利于减少软硬件的重复开发,大大的节省了人力、物力,满足了实际需求。     

半实物仿真中试验总控软件的设计与实现

试验总控软件是应用于半实物仿真中对参试系统进行管理和控制的一种软件,它可以对半实物仿真中的参试系统进行配置,实现对整个试验仿真的管理和监控。解析各参试系统的数据交互协议是试验总控软件对参试系统进行监控和管理的关键功能。通常试验总控软件解析功能代码完全按照各参试系统数据交互协议开发,这样一旦数据交互协议发生更改,解析功能代码需要根据新协议重新开发导致软件重复开发,影响软件开发效率和通用性。为了解决这个问题,文中提出一种试验总控软件设计框架并采用动态解析数据帧技术将解析代码与数据交互协议隔离,不仅提高软件通用性,同时缩短半实物仿真开发周期,减少人力财力开支。     

Observation of room temperature negative differential resistance in solution synthesized ZnO nanorod

We report the observation of negative differential resistance (NDR) in solution synthesized ZnO nanorod. The ZnO nanorod was fabricated as a two terminal planar device using lithographically patterned Au electrodes. The measured current–voltage response of the device has shown a negative differential resistance behavior. The peak-to-valley current ratio of the NDR is found to be greater than 4. The mechanism of this observed NDR effect has been explained based on charge trapping and de-trapping at the nanoscale contacts. It is the first observation of negative differential resistance effect in solution synthesized ZnO nanorod.