Nanjing Tech University

About: Nanjing Tech University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Membrane. The organization has 21827 authors who have published 21794 publications receiving 364050 citations. The organization is also known as: Nangongda & Nánjīng Gōngyè Dàxúe.

Colorimetric sensing strategy for mercury(II) and melamine utilizing cysteamine-modified gold nanoparticles

Abstract: A quantitative colorimetric sensing strategy utilizing cysteamine modified gold nanoparticles (CA–AuNPs) as reporters for Hg2+ and melamine was demonstrated. Cysteamine is a cheap and commercially available aminothiol and is also the most important chelating ligand in coordination chemistry possessing the ability to coordinate to Hg2+ and melamine. The terminal thiol group in cysteamine is used to bind to AuNPs and another terminal amine group is used as a colorimetric probe either for Hg2+ or melamine. By adjusting the pH, protonation of cysteamine's terminal amine groups allows for tuning of the surface charge on the cysteamine-modified gold nanoparticles. At acidic pH, the CA–AuNPs are positively charged due to the protonated amine groups, which may electrostatically bind melamine resulting in aggregation of CA–AuNPs, while at alkaline pH, the amine groups are deprotonated, and if Hg2+ is present, they may form an N–Hg2+–N structure to induce the aggregation of CA–AuNPs. The detection limits (S/N = 3) of Hg2+ and melamine were 30 nM and 80 nM respectively, which were comparable with or even lower than those of other single analyte methods. The proposed sensing mechanisms, which are based on electrostatic attraction for melamine and the N–Hg2+–N structure for Hg2+, were validated by zeta potential measurements. The facile one-step surface modification strategy for AuNPs is suitable for the effective analysis of large numbers of samples, which would open new opportunities for development of miniaturized Hg2+ and melamine sensors.

Ofloxacin degradation over Cu–Ce tyre carbon catalysts by the microwave assisted persulfate process

Abstract: In this study, the degradation of ofloxacin (OFX) over Cu–Ce tyre carbon catalysts by the microwave assisted persulfate process was examined for the first time. The results showed that the Cu–Ce tyre carbon catalysts dramatically improved OFX decay efficiency. The optimal reaction conditions were the Cu–Ce tyre carbon catalysts of 2.0 g/L and the persulfate dosage of 12.0 g/L under microwave power of 400 W at 60 °C. The OFX conversion and total organic carbon (TOC) removal reached 95.8% and 87.6%, respectively, after 60 min catalytic oxidation under optimal conditions. To identify the properties of Cu–Ce tyre carbon catalyst, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), the Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and the ultraviolet–visible (UV–vis) diffuse reflectance spectra studies have been carried out. Eleven kinds of degradation products and five pathways during degradation process of OFX and degradation products were identified by GC–MS and HRMS.