Tiandi Tang

Facile preparation of superhydrophobic biomimetic surface based on octadecyltrichlorosilane and silica nanoparticles.

The present paper describes the simple and low-cost process for the production of a superhydrophobic surface with micronano hierarchical structure from the chemisorptions of SiO(2) nanoparticles onto polymerized n-octadecylsilane. The process was carried out under ambient conditions without the use of expensive equipment. The as-prepared micronano-binary films exhibited a very high contact angle of 179.9 degrees and a low contact hysteresis of 2.5 degrees . On the basis of the results of the characterization techniques, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and contact angle (CA) measurements, a formation mechnism of the superhydrophobic micronano structure was proposed. Drop impact experiments on the modified-glass substrate showed that the as-prepared films possess a high-impalement threshold.

A rapid green route for fabricating efficient SERS substrates

This study develops a simple, rapid electrochemical approach for preparing dendrite-shaped Ag nanomaterials, which are well known as effective SERS substrates. In addition to yielding silver that exhibits a strong enhancement in SERS measurements when tested with 2,2′-dithiodipyridine and ethylenethiourea, this new fabrication method does not require any template, surfactants or supporting electrolyte, making it environment friendly. Analysis illustrates that the as-prepared Ag products are essentially pure silver consisting of abundant {111}-oriented crystallites. These Ag dendrites formed on a commercially available tin-doped indium oxide electrode could also be easily transferred onto other desired surfaces, making their application in SERS measurements more versatile.

Acidic hierarchical zeolite ZSM-5 supported Ru catalyst with high activity and selectivity in the seleno-functionalization of alkenes

The acidic hierarchical zeolite ZSM-5 (HZSM-5-H) was synthesized for the preparation of a supported Ru catalyst (Ru/HZSM-5-H). The obtained Ru/HZSM-5-H catalyst shows high activity and product selectivity in the seleno-functionalization of alkenes compared to γ-Al2O3, basic ETS-10 and acidic microporous zeolite ZSM-5 supported Ru catalysts (Ru/γ-Al2O3, Ru/ETS-10 and Ru/HZSM-5, respectively), as well as a homogeneous RuCl3 catalyst. The relatively strong acidic sites in Ru/HZSM-5-H could benefit the adsorption of styrenes and the activation of the CC bond. Meanwhile, Ru4+ in Ru/HZSM-5-H could facilitate the formation of electrophilic selenium species as compared to Ru0 species. In addition, the Ru/HZSM-5-M catalyst exhibits broad substrate compatibility in the difunctionalization of alkenes.

Zeolite Y nanoparticle assemblies with high activity in the direct hydration of terminal alkynes

A strong acidic zeolite Y nanoparticle assembly (HNANO-Y) with a micro–meso–macroporous structure was synthesized and used as a highly efficient heterogeneous catalyst for the hydration of alkynes to prepare ketone compounds, as compared to acidic mesoporous zeolite ZSM-5 and Beta catalysts. This feature should be assigned to the fact that the micro–meso–macroporous structure in the HNANO-Y benefits mass transfer and the strongly acidic sites on HNANO-Y facilitate alkyne hydration activity. The catalyst can be reused six times without loss of activity.

Heterogeneous Co-catalyzed direct 2-alkylation of azoles with ethers

The direct 2-alkylation of oxazoles and thiazoles with ethers through cross-dehydrogenative coupling reaction using Co-containing mesoporous zeolite ETS-10 as the heterogeneous catalyst is described. The basic Co-containing mesoporous zeolite ETS-10 catalyst facilitates this cross-dehydrogenative coupling reaction through metal-base synergy catalytic principle.

Fabrication of noble-metal catalysts with a desired surface wettability and their applications in deciphering multiphase reactions.

Noble-metal Pd and Pt catalysts with a wide range of surface wettability were fabricated through an electrochemical approach and were characterized with scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The importance of surface wettability of solid catalysts in multiphase reactions-especially their correlation to the nature of the studied chemical system-was investigated by reducing oxygen in an alkaline solution and oxidizing hydrogen peroxide and sodium formate in alkaline or buffered solutions at the as-prepared catalysts. These experiments illustrate that the nature of a multiphase reaction plays a critical role in determining the influence of surface wettability on the catalyst performance, providing a unique approach to decipher the reaction process. The investigation allows us to gain new insights into the electrochemical oxidation of sodium formate.