- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Passive Sampling of Gaseous Elemental Mercury Based on a Composite TiO2NP/AuNP Layer
摘要： Passive sampling systems (PASs) are a low cost strategy to quantify Hg levels in air over both different environmental locations and time periods of few hours to weeks/months. For this reason, novel nanostructured materials have been designed and developed. They consist of an adsorbent layer made of titania nanoparticles (TiO2NPs, ≤25 nm diameter) ?nely decorated with gold nanoparticles. The TiO2NPs functionalization occurred for the photocatalytic properties of titania-anatase when UV-irradiated in an aqueous solution containing HAuCl4. The resulting nanostructured suspension was deposited by drop-casting on a thin quartz slices, dried and then incorporated into a common axial sampler to be investigated as a potential PAS device. The morphological characteristics of the sample were studied by High-Resolution Transmission Electron Microscopy, Atomic Force Microscopy, and Optical Microscopy. UV-Vis spectra showed a blue shift of the membrane when exposed to Hg0 vapors. The adsorbed mercury was thermally desorbed for a few minutes, and then quanti?ed by a mercury vapor analyzer. Such a sampling system reported an ef?ciency of adsorption that was equal to ≈95%. Temperature and relative humidity only mildly affected the membrane performances. These structures seem to be promising candidates for mercury samplers, due to both the strong af?nity of gold with Hg, and the wide adsorbing surface.
关键词： TiO2NPs,PAS device,mercury vapors adsorbing layer,AuNPs,photocatalysis
更新于2025-09-23 15:21:01
-
Electrochemical Detection of 4-p-nitrophenol Based on TiO2NPs / RGO / AuNPs Composite Modified Glassy Carbon Electrode
摘要： A glassy carbon electrode modified with TiO2NPs/RGO/AuNPs was used as an electrochemical sensor to detect trace amounts of 4-p-nitrophenol (4-NP). The surface morphology of the composites was characterized by field-emission scanning electron microscopy (FE-SEM). The electrochemical characteristics of the composite electrode were analyzed by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The modified electrode exhibited outstanding electrochemical performance due to the large specific surface area and strong conductivity of composite material. The differential pulse voltammetry(DPV) and square wave voltammetry(SWV) were used for the trace detection of p-nitrophenol. The peak current of the two methods showed a high linear relationship with the 4-NP concentration. The detection range applied DPV method was 0.5-100μmol/L, the detection limit was 0.03μmol/L. When SWV was employed, detection range was from 0.5 to 100μmol/L, The detection limit was 0.08μmol/L. In this study, the electrochemical sensor had the advantage of large detection range, low detection limit, stable, simple and fast analysis. Based on these characteristics, the sensor can be considered as a potential sensor for the detection of 4-NP.
关键词： 4-NP,Square Wave Voltammetry,TiO2NPs,AuNPs,RGO,Differential Pulse Voltammetry
更新于2025-09-11 14:15:04