Enhanced plasmonic photocatalysis by SiO_2@Bi microspheres with hot-electron transportation channels via Bi–O–Si linkages

The semimetal Bi has received increasing interest as an alternative to noble metals for use in plasmonic photocatalysis. To enhance the photocatalytic efficiency of metallic Bi, Bi microspheres modified by SiO2 nanoparticles were fabricated by a facile method. Bi-O-Si bonds were formed between Bi and SiO2, and acted as a transportation channel for hot electrons. The SiO2@Bi microspheres exhibited an enhanced plasmon-mediated photocatalytic activity for the removal of NO in air under 280 nm light irradiation, as a result of the enlarged specific surface areas and the promotion of electron transfer via the Bi-O-Si bonds. The reaction mechanism of photocatalytic oxidation of NO by SiO2@Bi was revealed with electron spin resonance and in situ diffuse reflectance infrared Fourier transform spectroscopy experiments, and involved the chain reaction NO -> NO2 -> NO3- with center dot OH and center dot O-2(-) radicals as the main reactive species. The present work could provide new insights into the in-depth mechanistic understanding of Bi plasmonic photocatalysis and the design of high-performance Bi-based photocatalysts. (C) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

一种Rhodol型氟离子荧光探针的合成及性能研究

氟离子作为一种特殊的氢键受体,对硅、硼有很强的亲和力,被认为是最重要的阴离子之一。以Rhodol类衍生物和叔丁基二苯基氯硅烷为原料,合成了一种可用于检测氟离子的新型荧光探针。通过红外光谱、元素分析、飞行质谱、热重分析、核磁共振氢谱和核磁共振碳谱对探针的结构进行表征。通过荧光和紫外-可见光谱法研究探针对氟离子的检测能力。实验结果表明,氟离子浓度范围为0~10μmol/L时,荧光强度与氟离子浓度的关系曲线为y=138.01x+3859.8;紫外吸光度与氟离子浓度的关系曲线为y=0.0133x+0.3296;说明探针可用于溶液中氟离子的定量检测。