Highly fluorescent silicon quantum dots decorated silica microspheres for selective detection and removal of Au3+ and subsequent catalytic application

Sensitive detection and efficient removal of Au3+ are important for environmental monitoring and remediation. In this study, silicon quantum dots (SiQDs) were prepared with 3-aminopropyl trimethoxysilane as the silicon source and boric acid as the doping substance to enhance fluorescence quantum yield. The obtained SiQDs possessed fluorescence sensing ability of Au3+ and were successfully decorated on the meso porous silica microspheres (SiO 2 ), giving SiO2-SiQDs. Owing to the high affinity for Au(3+ )and the relatively large surface area, the SiO2-SiQDs exhibited not only selective fluorescence detection of Au 3+ in water matrix with a relatively low limit of detection (13.671 mu g L-1), but also efficient adsorption of Au(3+ )with a maximal adsorption capacity of 530.7 mg g(-1). Besides, the Au3+ adsorbed on the SiO2-SiQDs could be in-situ reduced into evenly dispersed small-size gold nanoparticles, showing high catalytic efficiency for the reduction of 4-nitrophenol. The remarkable performance of SiO2-SiQDs on detection, adsorption and reusability demonstrated its multi-purposed applicabilities. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.