Jinli Zhang

Performance of facet-controlled Pd nanocrystals in 2-ethylanthraquinone hydrogenation

In this study, single-crystal Pd nanocrystals with exposed (100) and (111) facets were prepared and their catalytic performance were compared in 2-ethylanthraquinone hydrogenation reaction through immobilization on γ-Al2O3 as catalyst. Our experimental results combined with density functional theory calculations showed that the Pd (100) facet was more active than Pd (111) in CO hydrogenation but less active in saturation of aromatic rings. Directed by this result, a high-performance Pd/γ-Al2O3 nanocatalyst was successfully prepared using a one-step synthesis method, which could not only control the exposure of the Pd (100) facet but also increase the stability of Pd components. This catalyst exhibited superior catalytic performance with a hydrogenation efficiency of up to 15.0 g L−1 and a selectivity of 99.1% under mild reaction conditions (0.2 MPa, 50 °C, 15 min), which was superior to that of the catalyst prepared by an impregnation method.

Synthesis and sensing application of glutathione-capped platinum nanoparticles

Glutathione (GSH) is chosen as a nucleation template to synthesize Pt-based peroxidase nanomimetics ranging from 2.3 to 3.6 nm, of which the surface charge states are greatly associated with the molar ratio of [K2PtCl4]/[GSH]. GSH-Pt3.3 consisting of 67% Pt0 and 33% Pt2+ possesses the highest peroxidase-like activity, while GSH-Pt3.6 comprising 82% Pt0 and 18% Pt2+ exhibits the most efficient radical scavenging capability. Owing to the Hg2+-induced inhibition of peroxidase mimicking activities, a series of Pt-based nanozymes are employed to explore colorimetric assays of Hg2+ in aqueous samples with ultrahigh sensitivity. The limit of detection (LOD) can reach 0.25 nM by using GSH-Pt with an average diameter of 3.6 nm. GSH-Pt is a promising candidate for colorimetric assay of Hg2+ in both drinking water and biological fluid.

Polyamide thin film composite membrane using mixed amines of thiourea and m-phenylenediamine

Polyamide thin film composite nanofiltration membranes were synthesized on the polyethersulfone (PES) support via the interfacial polymerization between trimesoyl chloride (TMC) and the amine mixture of m-phenylenediamine (MPD) and thiourea (TU). It is indicated that the composite membrane (PES-M5T5) prepared at the MPD/TU ratio of 5u2006:u20065 shows higher flux and glucose rejection than the membranes prepared using the individual amine. Further the optimal membrane PES-M5T5-TEA, prepared in the presence of triethylamine (TEA) additive, shows the largest flux of 39.7 L m−2 h−1 at an operation pressure of 1.6 MPa and the glucose rejection higher than 97.0%. In combination with characterizations of ATR-IR, Raman, SEM, XPS, AFM and contact angle measurements, it is illustrated that the TEA additive can promote the IP between TMC and MPD + TU, resulting in more amount of thioamide structures generated in the top layers of PES-M5T5-TEA, which can form more free volume and consequently improve the membrane flux. In addition, the PES-M5T5-TEA membrane shows excellent chlorine resistance against immersion of 200 ppm NaClO solution more than 100 h.

Intrinsic Enantioselectivity of Natural Polynucleotides Modulated by Copper Ions

Natural polynucleotides including Micrococcus lysodeikticus and calf thymus DNA exhibit enantioselective recognition to S-ofloxacin regulated by Cu(2+). This is the first report that ofloxacin and Cu(2+) have cooperative effects on the local distortions of polynucleotides. At the [Cu(2+)]/[base] ratio of 0.1, S-ofloxacin is more liable to induce the locally distorted structures of polynucleotides, of which the association constant of S-ofloxacin toward DNA-Cu(II) is three times higher than that of the R-enantiomer. The apparent increase of adsorption capability and cooperativity, as well as the change of adsorption mechanism were detected in the adsorption of ofloxacin enantiomers on polynucleotides upon Cu(II)-coordination. This study not only discloses the effect of the chiral drug on the structural transition of long double-stranded DNA, but provides fundamental data to develop a novel enantioseparation method based on natural polynucleotides.