Xiao Dan Sun

Facile synthesis of high photocatalytic active porous g-C3N4 with ZnCl2 template

Zinc chloride was utilized as the multi-functional modifier with dicyandiamide to synthesize porous g-C3N4, it not only played the role of pore-former in the resulting composite, but also acted as the assistant in succeeding adsorption of methyl orange (MO). Adjusting the quantity of ZnCl2 additive combined with the concentration of acidic washing liquid could control the amount and distribution of residual zinc species in the g-C3N4, in order to enhance the activity of the photocatalyst. The resulting composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflection spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS) as well as photoluminescence (PL) to assess the influence of residual zinc species on the physical and optical property of the composite. And they were evaluated in the photocatalytic degradation of MO in the visible light region, exhibiting an activity 240% higher than that of g-C3N4.

Novel fabrication of an efficient solid base: carbon-doped MgO–ZnO composite and its CO2 capture at 473 K

A new strategy for fabricating an optimal porous strong base was reported for the first time. Magnesium and zinc acetates were mixed by microwave irradiation followed by carbonization at 823 K. Zn incorporation enabled the magnesia nanoparticles to have more surface defects, and about 80% of the basic sites were strong ones with the ability to capture CO2 at 473 K, which is the highest proportion to date. These porous binary metal oxides had large surface areas between 130–296 m2 g−1.

In Situ Loading of Drugs into Mesoporous Silica SBA-15.

In a new strategy for loading drugs into mesoporous silica, a hydrophilic (heparin) or hydrophobic drug (ibuprofen) is encapsulated directly in a one-pot synthesis by evaporation-induced self-assembly. In situ drug loading significantly cuts down the preparation time and dramatically increases the loaded amount and released fraction of the drug, and appropriate drug additives favor a mesoporous structure of the vessels. Drug loading was verified by FTIR spectroscopy and release tests, which revealed much longer release with a larger amount of heparin or ibuprofen compared to postloaded SBA-15. Besides, the in vitro anticoagulation properties of the released heparin and the biocompatibility of the vessels were carefully assessed, including activated partial thromboplastin time, thrombin time, hemolysis, platelet adhesion experiments, and the morphologies of red blood cells. A concept of new drug-release agents with soft core and hard shell is proposed and offers guidance for the design of novel drug-delivery systems.

Creating an Optimal Microenvironment within Mesoporous Silica MCM-41 for Capture of Tobacco-Specific Nitrosamines in Solution

To meet the requirement of capturing tobacco-specific nitrosamines (TSNA) for environment protection, a unique microenvironment was carefully created inside the channels of mesoporous silica MCM-41. In situ carbonization of template micelles at 923 K, combined with the excess aluminum used in one-pot synthesis of MCM-41, is adopted to tailor the tortuosity of mecsoporous channels, while loaded metal oxides (5 wt %) and the Al component in the framework are employed to exert the necessary electrostatic interaction toward the target carcinogens TSNA in solution. The elaborated microenvironment created in mesoporous sorbents was characterized with XRD, N2 adsorption-desorption, TEM, XPS, and TG-DSC methods. Various solutions of Burley- and Virginia-type tobaccos were used to assess the adsorption performance of new mesoporous sorbents, and the influence of the solid-to-liquid ratio, adsorption time, and loading amount of CuO on the adsorption was carefully examined. The representative sample 5%Cu/AM-10c could capture 27.2% of TSNA in Burley tobacco solution, and its capacity reached 0.3 mg g-1 in Snus tobacco extract solution, offering a promising candidate for the protection of the environment and public health.