Influences of MgO(001) and TiO2(101) Supports on the Structures and Properties of Au Nanoclusters

Due to the unique structures, photoelectric properties, good catalytic activity, and broad potential applications, gold nanoclusters (Aun) received extensive attention in catalysis, bioengineering, environmental engineering, and so on. In the present work, the structures and properties of Aun adsorbed on the MgO(001) and TiO2(101) surfaces were investigated by density functional theory. The results showed that the catalytic properties of Aun will be enhanced when Aun is adsorbed on certain supports. Because the difference of the outer electronic structure of metals in supports, the direction of the charge transfer was different, thus inducing the different charge distribution on Aun. When Aun was adsorbed on MgO(001) [TiO2(101)] surface, Aun will have negative [positive] charges and thus higher catalytic activity in oxidation [reduction] reaction. The variation of surface charges caused by the support makes Aun possess different catalytic activity in different systems. Moreover, the electronic structure of the support will make an obvious influence on the s and d density of states of Aun, which should be the intrinsic reason that induces the variations of its structure and properties. These results should be an important theoretical reference for designing Aun as the photocatalyst applied to the different oxidation and reduction reactions

A promising catalytic solution of NO reduction by CO using g-C3N4/TiO2: A DFT study

The direct catalytic reduction of nitric oxide (NO) by carbon monoxide (CO) to form harmless N-2 and CO2 is an ideal strategy to simultaneously remove both these hazardous gases. To investigate the feasibility of using graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) to catalyze the NO reduction by CO, we systematically explore the effect of the interfacial coupling between g-C3N4 and TiO2 on the photo-induced carrier separation, the light absorption, and the surface reaction for the NO reduction by using density functional theory. The g-C3N4/TiO2 is predicted to have a better photocatalytic activity for NO reduction than g-C3N4, due to the enhanced light absorption intensity and the accelerated separation of the photo excited electron-hole pairs. By comparing the reaction routes on g-C3N4/TiO2 and g-C3N4, the results indicate that the introduction of TiO2 can keep the surface reaction process intact with the NO dissociation (N2O formation) being the rate-determining (crucial) step. Moreover, TiO2 can facilitate the desorption of NO reduction products, avoiding the deactivation of g-C3N4. This work shows that the composition of TiO2 into g-C3N4 provides a promising catalyst in NO reduction by CO. (C) 2021 Elsevier Inc. All rights reserved

Effects of 4d transition metals doping on the photocatalytic activities of anatase TiO2 (101) surface

Aiming at improving the visible-light photocatalytic activities of TiO2(101) surface we make an in-depth study on the TiO2(101) doped with 4d transition metal (TM) atoms. It is shown that the 4d TM dopings can not only produce new impurity energy bands in the band gap but also result in the semiconductor-metal phase transition. Consequently, the visible-light absorption is strongly strengthened due to the dopings of Y, Zr, Nb, Mo, and Ag, while it is only weakly improved for Tc, Ru, Rh, Pd, and Cd dopings. The improvement in visible-light absorption can be attributed to the intraband or interband transition of electrons. Moreover, the photocatalytic activities are explored, and we find Y and Ag dopings can effectively enhance the photocatalytic activity of TiO2(101) surface. Thus the mechanism of improving photocatalytic activity of TiO2(101) has been clearly addressed, which is beneficial to further experimental and theoretical researches on TiO2 photocatalysts

"Cell-addictive" dual-target traceable nanodrug for Parkinson's disease treatment via flotillins pathway

alpha-synclein (aS) aggregation is a representative molecular feature of the pathogenesis of Parkinson&#39;s disease (PD). Epigallocatechin gallate (EGCG) can prevent alpha S aggregation in vitro. However, the in vivo effects of PD treatment are poor due to the obstacles of EGCG accumulation in dopaminergic neurons, such as the blood brain barrier and high binding affinities between EGCG and membrane proteins. Therefore, the key to PD treatment lies in visual examination of EGCG accumulation in dopaminergic neurons. Methods: DSPE-PEG-B6, DSPE-PEG-MA, DSPE-PEG-phenylboronic acid, and superparamagnetic iron oxide nanocubes were self-assembled into tracing nanoparticles (NPs). EGCG was then conjugated on the surface of the NPs through the formation of boronate ester bonds to form a &quot;cell-addictive&quot; dual-target traceable nanodrug (B6ME-NPs). B6ME-NPs were then used for PD treatment via intravenous injection. Results: After treatment with B6ME-NPs, the PD-like characteristics was alleviated significantly. First, the amount of EGCG accumulation in PD lesions was markedly enhanced and traced via magnetic resonance imaging. Further, alpha S aggregation was greatly inhibited. Finally, the dopaminergic neurons were considerably increased. Conclusion: Due to their low price, simple preparation, safety, and excellent therapeutic effect on PD, B6ME-NPs are expected to have potential application in PD treatment.</p

Cell-addictive dual-target traceable nanodrug for Parkinson's disease treatment via flotillins pathway

alpha-synclein (aS) aggregation is a representative molecular feature of the pathogenesis of Parkinson&#39;s disease (PD). Epigallocatechin gallate (EGCG) can prevent alpha S aggregation in vitro. However, the in vivo effects of PD treatment are poor due to the obstacles of EGCG accumulation in dopaminergic neurons, such as the blood brain barrier and high binding affinities between EGCG and membrane proteins. Therefore, the key to PD treatment lies in visual examination of EGCG accumulation in dopaminergic neurons. Methods: DSPE-PEG-B6, DSPE-PEG-MA, DSPE-PEG-phenylboronic acid, and superparamagnetic iron oxide nanocubes were self-assembled into tracing nanoparticles (NPs). EGCG was then conjugated on the surface of the NPs through the formation of boronate ester bonds to form a &quot;cell-addictive&quot; dual-target traceable nanodrug (B6ME-NPs). B6ME-NPs were then used for PD treatment via intravenous injection. Results: After treatment with B6ME-NPs, the PD-like characteristics was alleviated significantly. First, the amount of EGCG accumulation in PD lesions was markedly enhanced and traced via magnetic resonance imaging. Further, alpha S aggregation was greatly inhibited. Finally, the dopaminergic neurons were considerably increased. Conclusion: Due to their low price, simple preparation, safety, and excellent therapeutic effect on PD, B6ME-NPs are expected to have potential application in PD treatment.</p