排序方式: 共有16条查询结果,搜索用时 46 毫秒
1.
Mohammed Ahmed Shehab Nikita Sharma Andrea Valsesia Gbor Karacs Ferenc Kristly Tams Kos Anett Katalin Lesk Lilla Nnai Klara Hernadi Zoltn Nmeth 《Molecules (Basel, Switzerland)》2022,27(9)
Nowadays, the use of hybrid structures and multi-component materials is gaining ground in the fields of environmental protection, water treatment and removal of organic pollutants. This study describes promising, cheap and photoactive self-supported hybrid membranes as a possible solution for wastewater treatment applications. In the course of this research work, the photocatalytic performance of titania nanowire (TiO2 NW)-based hybrid membranes in the adsorption and degradation of methylene blue (MB) under UV irradiation was investigated. Characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffractometry (XRD) were used to study the morphology and surface of the as-prepared hybrid membranes. We tested the photocatalytic efficiency of the as-prepared membranes in decomposing methylene blue (MB) under UV light irradiation. The hybrid membranes achieved the removal of MB with a degradation efficiency of 90% in 60 min. The high efficiency can be attributed to the presence of binary components in the membrane that enhanced both the adsorption capability and the photocatalytic ability of the membranes. The results obtained suggest that multicomponent hybrid membranes could be promising candidates for future photocatalysis-based water treatment technologies that also take into account the principles of circular economy. 相似文献
2.
Xiaoming Ma Dr. Yongli Shen Dr. Shuang Yao Miao Shu Prof. Rui Si Prof. Changhua An 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(18):4143-4149
The key to the electrochemical conversion of CO2 lies in the development of efficient electrocatalysts with ease of operation, good conductivity, and rich active sites that fulfil the desired reaction direction and selectivity. Herein, an oxidative etching of Au20Cu80 alloy is used for the synthesis of a nanoporous Au3Cu alloy, representing a facile strategy for tuning the surface electronic properties and altering the adsorption behavior of the intermediates. HRTEM, XPS, and EXAFS results reveal that the curved surface of the synthesized nanoporous Au3Cu is rich in gold with unsaturated coordination conditions. It can be used directly as a self-supported electrode for CO2 reduction, and exhibits high Faradaic efficiency (FE) of 98.12 % toward CO at a potential of −0.7 V versus the reversible hydrogen electrode (RHE). The FE is 1.47 times that over the as-made single nanoporous Au. Density functional theory reveals that *CO has a relatively long distance on the surface of nanoporous Au3Cu, making desorption of CO easier and avoiding CO poisoning. The Hirshfeld charge distribution shows that the Au atoms have a negative charge and the Cu atoms exhibit a positive charge, which separately bond to the C atom and O atom in the *COOH intermediate through a bidentate mode. This affords the lowest *COOH adsorption free energy and low desorption energy for CO molecules. 相似文献
3.
Meng Zhang Yan Wang Yuanyuan Zhang Dr. Jun Song Prof. Yang Si Prof. Jianhua Yan Prof. Chunlan Ma Prof. Yi-Tao Liu Prof. Jianyong Yu Prof. Bin Ding 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23452-23460
Recently, various titanium dioxide (TiO2) nanostructures have received increasing attention in the fields of energy conversion and storage owing to their electrochemical properties. However, these particulate nanomaterials exclusively exist in the powder form, which may cause health risks and environmental hazards. Herein we report a novel, highly elastic bulk form of TiO2 for safe use and easy recycling. Specifically, TiO2 nanofibrous aerogels (NAs) consisting of resiliently bonded, flexible TiO2 nanofibers are constructed, which have an ultralow bulk density, ultrahigh porosity, and excellent elasticity. To promote charge transfer, they are subjected to lithium reduction to generate abundant oxygen vacancies, which can modulate the electronic structure of TiO2, resulting in a conductivity up to 38.2 mS cm−1. As a proof-of-concept demonstration, the conductive and elastic TiO2 NAs serve as a new type of self-supported electrocatalyst for ambient nitrogen fixation, achieving an ammonia yield of 4.19×10−10 mol s−1 cm−2 and a Faradaic efficiency of 20.3 %. The origin of the electrocatalytic activity is revealed by DFT calculations. 相似文献
4.
Chunfeng Meng Tianhui Chen Chun Fang Yunhui Huang Pinfei Hu Yongli Tong Ting Bian Jiaojiao Zhang Zhaoxuan Wang Aihua Yuan 《化学:亚洲杂志》2019,14(23):4289-4295
Recently, carboxylate metal‐organic framework (MOF) materials were reported to perform well as anode materials for lithium‐ion batteries (LIBs); however, the presumed lithium storage mechanism of MOFs is controversial. To gain insight into the mechanism of MOFs as anode materials for LIBs, a self‐supported Cu‐TCNQ (TCNQ: 7,7,8,8‐tetracyanoquinodimethane) film was fabricated via an in situ redox routine, and directly used as electrode for LIBs. The first discharge and charge specific capacities of the self‐supported Cu‐TCNQ electrode are 373.4 and 219.4 mAh g?1, respectively. After 500 cycles, the reversible specific capacity of Cu‐TCNQ reaches 280.9 mAh g?1 at a current density of 100 mA g?1. Mutually validated data reveal that the high capacity is ascribed to the multiple‐electron redox conversion of both metal ions and ligands, as well as the reversible insertion and desertion of Li+ ions into the benzene rings of ligands. This work raises the expectation for MOFs as electrode materials of LIBs by utilizing multiple active sites and provides new clues for designing improved electrode materials for LIBs. 相似文献
5.
采用磁控溅射镀金银膜,长时间热处理合金化制备前驱体合金,以渐进浓度的硝酸自由腐蚀去合金化成功制备出具有自支撑结构的纳米多孔金薄膜。采用扫描电镜和X射线能谱仪对去合金腐蚀前后样品的形貌和成分进行了分析,结果表明:400 ℃,36 h的热处理使得薄膜样品完全合金化,获得了结晶致密的Au42Ag58合金膜;渐进浓度的自由腐蚀避免了薄膜的完全开裂,获得了样品尺寸大于15 mm15 mm、厚度400~500 nm、孔隙率约56%、具有自支撑结构的纳米多孔金薄膜,其微观结构为连续的三维多孔结构,系带尺寸40~140 nm,80~100 nm的系带达58%。 相似文献
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7.
Rongshuo Wang Fanhao Tang Hao Jiang Dongxu He 《Particle & Particle Systems Characterization》2021,38(11):2100189
Reducing energy consumption and improving energy utilization efficiency has become the focus of research in the 21st century. Electrocatalytic water splitting is one of the promising strategies for producing hydrogen energy. In this study, the non-noble nickel-iron layered double hydroxide (NiFe-LDH) catalyst is deposited on the electrochemically intercalated graphite/graphene (G/GE) substrate and directly used as the self-supported and binder-free electrode for electrocatalytic water oxidation. The Ni2Fe1-LDH@G/GE catalyst shows a low overpotential of 194 mV at a current density of 10 mA cm–2, which is better than the noble metal catalyst IrO2 (314 mV) and RuO2 (330 mV) and many other related works. This research provides a facile way to directly prepare the catalyst electrode with high performance and low cost. 相似文献
8.
软X射线波段滤光膜材料大都为自支撑金属薄膜,实验室环境下自支撑薄膜长期与空气接触表面易氧化,空气中的杂质原子进入自支撑薄膜内部,致使自支撑膜光学性能大幅下降.5 nm至20 nm软X射线波段Zr具有较低的质量吸收系数和较小的密度,在该波段Zr滤光膜透过率较高.采用脱模剂法制备自支撑Zr膜,在洁净的浮法玻璃上蒸镀一层Na... 相似文献
9.
Yikang Cong Shengsheng Huang Yan Mei Prof. Dr. Ting-Ting Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15866-15888
Electrocatalytic water splitting has been considered as a promising strategy for the sustainable evolution of hydrogen energy and storage of intermittent electric energy. Efficient catalysts for electrocatalytic water splitting are urgently demanded to decrease the overpotentials and promote the sluggish reaction kinetics. Carbon-based composites, including heteroatom-doped carbon materials, metals/alloys@carbon composites, metal compounds@carbon composites, and atomically dispersed metal sites@carbon composites have been widely used as the catalysts due to their fascinating properties. However, these electrocatalysts are almost powdery form, and should be cast on the current collector by using the polymeric binder, which would result in the unsatisfied electrocatalytic performance. In comparison, a self-supported electrode architecture is highly attractive. Recently, self-supported metal–organic frameworks (MOFs) constructed by coordination of metal centers and organic ligands have been considered as suitable templates/precursors to construct free-standing carbon-based composites grown on conductive substrate. MOFs-derived carbon-based composites have various merits, such as the well-aligned array architecture and evenly distributed active sites, and easy functionalization with other species, which make them suitable alternatives to non-noble metal-included electrocatalysts. In this review, we intend to show the research progresses by employment of MOFs as precursors to prepare self-supported carbon-based composites. Focusing on these MOFs-derived carbon-based nanomaterials, the latest advances in their controllable synthesis, composition regulation, electrocatalytic performances in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting (OWS) are presented. Finally, the challenges and perspectives are showed for the further developments of MOFs-derived self-supported carbon-based nanomaterials in electrocatalytic reactions. 相似文献
10.
自支撑电极材料在超级电容器中有着广泛的应用. 碳材料具有结构多样、来源丰富、价格低廉以及性能稳定等优点,是构建三维自支撑电极材料的首选基底材料. 本文结合作者课题组的研究工作,从“由上而下”和“由下而上”两个方面,概述了设计、制备三维自支撑电极材料的常用方法及材料的电容性能,希望对开发利用天然可再生资源,制备高性能的自支撑电极材料及其在超级电容器材料中的应用有所帮助. 相似文献