Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

Salting-Out Effect of Ionic Liquids on Poly(propylene glycol) (PPG): Formation of PPG + Ionic Liquid Aqueous Two-Phase Systems

Abstract: In the present work, aqueous poly(propylene glycol) (PPG) solution was separated into aqueous two-phase systems (ATPSs) in the presence of ionic liquid 1-allyl-3-methylimidazolium chloride ([Amim]Cl), 1-butyl-3-methylimidazolium acetate ([C4mim]Ac), or 1-butyl-3-methylimidazolium chloride ([C4mim]Cl). The top phase was PPG-rich, whereas the bottom phase was ionic liquid (IL)-rich. Liquid−liquid equilibrium data for the ATPSs and the salting-out coefficients of the ILs have been determined at 298.15 K and atmospheric pressure. It was shown that the binodal curves and the tie-lines could be described by a three-parameter equation and the Othmer−Tobias and Bancroft equations, respectively. The salting-out ability of the ILs on PPG was found to follow the order: [Amim]Cl > [C4mim]Ac > [C4mim]Cl > [C4mim][BF4]. Since PPG is a thermo-sensitive polymer and can be recovered simply by heating, these novel ATPSs are expected to have applications in the recycling and/or enrichment of hydrophilic ILs from aqueous sol...

Spectroscopic Verification of Adsorbed Hydroxy Intermediates in the Bifunctional Mechanism of the Hydrogen Oxidation Reaction.

Abstract: Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion-exchange-membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface-enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad ) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum-alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity.

Light induced double ‘on’ state anti-ambipolar behavior and self-driven photoswitching in p-WSe 2 /n-SnS 2 heterostructures

Abstract: P–n junctions based on vertically stacked van der Waals (vdW) materials have attracted extensive attentions and may offer novel physical performances for the design of next-generation electronics. Here, vertically stacked p-WSe2/n-SnS2 heterostructures have been fabricated by a polymethyl methacrylate (PMMA)-assisted transfer method. The unique electronical properties and self-driven photoelectric characteristics of the heterostructures are measured. The transfer current of the heterostructures show gate-tunable 'anti-ambipolar' behavior under dark condition with the maximum of the on/off ratio exceeding 105, while under light illumination it triggers double 'on' state anti-ambipolar behavior. The 'anti-ambipolar' behavior under dark condition and the 'on' state I under light illumination is originating from the in series of p-channel in WSe2 and n-channel in SnS2, while the 'on' state II can be attributed to the gate-controlled Schottky barrier modulation between the heterostructure and the Au electrodes. The heterostructure also shows self-driven photoswitching performance under 532 nm laser, which can be attributed to the type-II band alignment and the build-in potential of p–n heterostructure.