Synthesis of novel derivatives of murrayafoline A and their inhibitory effect on LPS-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells

Cu(I)-catalyzed Huisgen–Meldal–Sharpless type dipolar ‘click’ reactions between azido-tetrathiafulvalene derivatives and ethynylferrocene yield the first examples of ferrocenyl-1,2,3-triazolyl-tetrathiafulvalene assemblies (4a, 4b). The electrochemical behavior of 4a and 4b, which integrate two distinctive redox probes, has been investigated, and their binding ability for various transition-metal cations has been studied by cyclic voltammetry. The contribution of the triazolyl ring in the guest binding process is illustrated by the specific electrochemical recognition of Zn2+ by receptor 4b

Effect of large graphene particle size on structure, optical property and photocatalytic activity of graphene-titanate nanotube composites

Available online 19 October 2021In this work we investigate the crystal transformation and optical properties of hydrothermal titania nanotube (TNT) when combining with large size of exfoliated graphene achieved by electrochemical process (EC-Gr). The TNT monoclinic structure has been changed to TiO2 anatase phase when TNT was grown in the presence of graphene dispersion. The effect of graphene on the evolution of TNT crystal could be understood by the interaction of carbon elements in graphene and Ti4+ ions in the titania structure. Due to the carrier separation which reduced recombination rate of excited photoelectrons and holes revealed by photoluminescence characterizations, the visible light photocatalytic activity in degradation of methylene blue in solution of the composite was enhanced. The photocatalytic enhancement was discussed and clarified based on UV–vis diffuse absorption spectra and time-resolved photoluminescence investigation.Vo Cao Minh, Phan Tan Dat, Pham Thi Thuy, Nguyen Xuan Sang, Nguyen Tri Tuan, Tran Thanh Tung, Dusan Losi

Engineering of ZnO/Graphene Nanocomposite for Enhancing Visible Photocatalytic Ability

Herein, the visible light-photocatalytic performance of synthesized ZnO/Gr composite materials with different Gr content under various conditions, i.e., pH, dye concentration, and different scavengers (to understand the photocatalytic activity mechanism) is systematically investigated. Photocatalytic performance is evaluated with the degradation of methylene blue (MB) in solution under sunlight irradiation. The presence of graphene (Gr) in the ZnO/Gr composites shows enhanced photocatalytic activity compared to pure ZnO under natural sunlight illumination. The highest photodegradation efficiency of 94% when the content of Gr is 1 wt% in comparison to 76% for the pure ZnO, corresponding to reaction rate constants of 0.01038 and 0.00615 min1 , respectively. Compared to recent publications, the degradation efficiency is high with relatively high dye concentration, low catalyst amount, and large solution volume. The enhanced visible light absorption and the reduction of bandgap value are attributed to the enhanced photocatalytic properties of the hybridized composite. Moreover, the investigation of the effect of scavenger substances shows that H2O2 strongly enhanced their photocatalytic ability, suggesting that holes (hþ) contribute as the reactive agent in the photodegradation process.Nguyen Xuan Sang, Tran Thi Ly Na, Luu Thi Lan Anh, Pham Thi Thuy, Nguyen Tri Tuan, Tran Thanh Tung, Anh Tuan Trong Tran, Quoc Hue Pho, Cameron James Shearer, and Dusan Losi