ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Hongbo Ding,Qingfeng Zhang,Zhaomeng Liu,Jue Wang,Ruifang Ma,Ling Fan,Tao Wang,Jianguo Zhao,Junmin Ge,Xianlu Lu,Xinzhi Yu,Bingan Lu
Lithium sulfur battery is considered one of the most promising rechargeable energy storage devices due to its ultrahigh theoretical energy density and specific capacity. It still cannot be applied because of some key problems. In particular, the shuttle effect of soluble polysulfide compounds leads to the rapid attenuation of battery capacity, short cycle life and serious self-discharge effect. TiO 2 quantum dots and polysulfide compounds have strong interactions and can capture soluble polysulfide compounds, thus inhibiting the shuttle effect. Herein, we introduce a battery separator based on TiO 2 quantum dots modified multi walled carbon nanotubes to solve the shuttle effect and adapt to the expansion of electrodes during charging and discharging. The interlayer has abundant spacing and excellent conductivity. This strategy can significantly improve the stability of lithium sulfur batteries. As a result, Li-S cells with MWCNTs@TiO 2 quantum dots modified separator deliver an initial capacity of 1083 mAh g −1 and keep a cycle capacity of 610 mAh g −1 after 600 cycles at the rate of 838 mA g −1 , which maintains an average capacity decay of only 0.072% per cycle. This simple and effective method can greatly improve the application capacity of lithium sulfur batteries.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Hanyang Gao,Wenfeng Shangguan,Guoxin Hu,Kunxu Zhu
By using monolayer titania quantum dots (MTQDs) colloid, a continuous and transparent ultrathin titania film was prepared simply by drop-cast or spray coating method at room temperature. The formation of this even and ultrathin film was not only because of the very thin thickness of two-dimensional MTQDs, but also because of the suppression of coffee-ring effect. The self-assembly behaviors of MTQDs were examined by AFM and the reason for the suppression of coffee-ring effect was discussed in detail. Furthermore, the photocatalytic performance of this MTQDs film was evaluated and an improvement was achieved by loading graphene. Comparison between MTQDs/graphene composite and sphere-shaped nanoTiO 2 /graphene composite indicated that, the face-to-face contact mode between MTQDs and graphene may contribute to the high activity of MTQDs/graphene composite.
研究领域:
材料科学
·
纳米技术
·
环境科学
✓ 已验证
DOI
高影响因子
Small
·
2018
·Vol. 14
·期 41
·1802443
·
IF 9.598
Xiao-Tian Gao,Ying Xie,Xiao-Dong Zhu,Ke-Ning Sun,Xu-Ming Xie,Yi-Tao Liu,Jian-Yong Yu,Bin Ding
Being conductive and flexible, 2D transition metal nitrides and carbides (MXenes) can serve in Li–S batteries as sulfur hosts to increase the conductivity and alleviate the volume expansion. However, the surface functional groups, such as OH and F, weaken the ability of bare MXenes in the chemisorption of polysulfides. Besides, they create numerous hydrogen bonds which make MXenes liable to restack, resulting in substantial loss of active area and, thus, inaccessibility of ions and electrolyte. Herein, a facile, one-step strategy is developed for the growth of TiO 2 quantum dots (QDs) on ultrathin MXene (Ti 3 C 2 T x ) nanosheets by cetyltrimethylammonium bromide-assisted solvothermal synthesis. These QDs act as spacers to isolate the MXene nanosheets from restacking, and preserve their 2D geometry which guarantees larger electrode–electrolyte contact area and higher sulfur loading. The stronger adsorption energy of polysulfides with TiO 2 (than with Ti 3 C 2 T x ), as proven by density functional theory calculations, is essential for better on-site polysulfide retention. The ultrathin nature and protected conductivity ensure rapid ion and electron diffusion, and the excellent flexibility maintains high mechanical integrity. In result, the TiO 2 QDs@MXene/S cathode exhibits significantly improved long-term cyclability and rate capability, disclosing a new opportunity toward fast and stable Li–S batteries.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
电池技术
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2024
·
IF 5.4
Ziwei Kan,Ye Chen,Qianyun Zhang,Luyi Pan,Aiying Chen,Ding Wang,Yi Wang,Guangming Wan,Bin He
The catheters coating can be effective in reducing bloodstream infection and thrombosis, which are the major complications in blood contact catheters. However, the surface functional coating is difficult to be implemented due to the high surface stretching force from the minor-caliber. In this work, we propose a covalent bonding coating of polydopamine/titanium dioxide quantum dots (PDA/TiO 2 QDs) on polyurethane (PU) catheters, which can fulfill a dual-function of antibacterial and antithrombosis. The PDA/TiO 2 QDs layer was prepared by dip-coating, where the intermediate transition layer of PDA was reacted with the internal hydroxyls of PU surface by pre-oxidation and bonds with the external TiO 2 QDs coating. The surface microstructures are analyzed by SEM, TEM and XPS methods, and the antimicrobial and anticoagulant performances are investigated by bacterial plate count and platelet adhesion tests. The oxidizing and hydrophilic effect of the top layer of TiO 2 QDs were enhanced by the QD-sized particles. The antibacterial activities of the PDA/TiO 2 QDs coating on PU catheters against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), especially to S. aureus , are evidenced by bacterial plate count test, reaching good bactericidal rates of 49.9 % against E. coli and 83.7 % against S. aureus , respectively. Platelet adhesion test and whole blood dynamic circulation modeling demonstrate that the PDA/TiO 2 QDs coating effectively inhibits platelet adhesion due to an excellent hydrophilicity of TiO 2 QDs surface, and thereafter reduce thrombus formation.
研究领域:
材料科学
·
生物材料
·
生物医学工程
·
表面化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）