Shaopeng Tian

The role of non-stoichiometric spinel for iso-butanol formation from biomass syngas over Zn–Cr based catalysts

A series of Zn–Cr based catalysts modified by K promoter has been prepared by different methods and their performances for iso-butanol formation from biomass syngas were investigated in a fixed bed reactor. The ZnCr-c catalyst which was prepared by co-precipitation method showed the best catalytic performance for iso-butanol formation, over which ca. 30% of CO conversion and ca. 20% of iso-butanol selectivity were achieved. Multi-characterization studies were then conducted to reveal the internal causes for different performances for iso-butanol formation over different catalysts including high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The results reveal that ZnCr-c catalyst contains the maximum amount of non-stoichiometric spinel among all the catalysts. This fact implies that the non-stoichiometric spinel is the active phase for iso-butanol synthesis from syngas. The reducibility, texture parameters and basic property of catalysts are further important factors for the formation of iso-butanol over Zn–Cr based catalysts from biomass syngas.

Facial strategy for radical species through Ag(I)-mediated oxidation of the alkyl trifluoroborates

ABSTRACT A rapid and highly efficient method for the radical formation using potassium alkylfluoroborates as radical precursor is devised and developed which conducts under relatively mild condition using silver(I) oxide as the oxidant. The observed silver mirror phenomenon hints at the fact that Ag2O is the real oxidant. This approach effectively overcomes the drawbacks-stringent reaction conditions and poor tolerance of a variety of functional groups. GRAPHICAL ABSTRACT

Blue phase liquid crystals stabilized by graphene oxide modified with aminoalkyl group

ABSTRACT In the present work, the graphene oxide/blue phase liquid crystal composites and long aminoalkyl chains functionalized graphene/blue phase liquid crystal composites were prepared by doping the additives into a blue phase exhibiting liquid crystal host. It is found that the blue phase temperature range could be widened by dispersing a small amount of functionalized graphene. It suggests that anisotropic two-dimensional flake nanoparticles may be of great usefulness for stabilizing blue phases.

Au monolayer film coating with graphene oxide for surface enhanced Raman effect

A self-terminated electrochemical atomic layer deposition process is developed to fabricate Au monolayer (ML) film layer-by-layer. It is found that the under potential deposited hydrogen (Hupd) provides perfect termination after each ML deposition and the further ML growth can be replicated after a surface activation using a positive potential to remove the Hupd layer. Voltammetric measurements, deposition current analysis, and EQCM show clear characteristics of UPD hydrogen surface termination and the ML deposition. Both XRR and HREED confirm the Au ML film formation. Moreover, the Au ML film appears to be effective for surface enhanced Raman effect of GO on the Au ML film.

Advanced electro-optic properties of nematic liquid crystal doped with high birefringence liquid crystal molecules

ABSTRACT The study of fast response nematic liquid crystal display material mixture and synthesis about compounds has always been an important subject in recent years. In this article, one type of high birefringence liquid crystal based on phenyl-diacetylenes was synthesized by sonogashira coupling reaction. A research is conducted on the effect of electro-optic properties of a widely used nematic liquid crystal mixture doped with the prepared high birefringence liquid crystal molecule which concentrations ranging from 1% to 5 wt%. While the results show that the steepness of electro-optic curves first increase and then decrease with the prepared high birefringence liquid crystal molecule content increasing, when the content of high birefringence liquid crystal molecule reaches 3%, electro-optic properties of the mixture liquid crystals are excellent.

A new-type composite film of cholesteric liquid crystal doped with PCBM for laser-damage prevention in both visible and near-infrared region

ABSTRACT Nowadays, with the increasing use of high-power laser, research and development of laser-damage prevention materials with multifunctional features and wideband wavelengths are urgent and indispensable. In the paper, cholestric liquid crystal (ChLC) is first proposed to be doped with a high-efficiency optical limiting material, 6, 6-phenyl C61-butyric acid methyl ester (PCBM), to fabricate a new-type laser-damage-prevention film. The ChLCs have the desired reflection wavelengths covering 750–2300 nm, which is an effective and potential candidate for the prevention of continuous or tuneable laser in near infrared (NIR) region. Meanwhile, the solubility of PCBM in LC and its nonlinear absorption property of are discussed, and it was proved that the good solubility of PCBM in LC contributed to the excellent nonlinear absorption of mixture (LC doped with PCBM). Taking advantages of this phenomenon, a novel composite film of ChLCs doped with PCBM is prepared by UV polymerization. As a result, the composite film not only performs broadband reflection in NIR region, but also exhibits a strong nonlinear absorption and excellent optical limiter properties in visible region, which proves the films potential application in laser damage prevention.