Evaluation of the influence of sulfur-based functional groups on the embedding of silver nanoparticles into the pores of MCM-41

The incorporation of noble metals in the pores of mesoporous silicas might produce materials with interesting catalytic and sensing capabilities, but the proper control of pore filling and the avoidance of nanoparticles migration to outside the pores are processes not yet completely understood. In this work, we evaluated the role of -SH and -SO3H groups post-grafted into MCM-41 on the production of silver nanoparticles by using 1-butanol as reducing agent. Thiol groups were the most efficient on promoting the formation of nanoparticles within the pores. Conversely, sulfonic groups establish electrostatic interactions with silver cations that preclude the formation of nanoparticle in yields comparable to thiol groups. MCM-41 without functional groups did not have good affinity to silver and the nanoparticles are produced outside the pores. This study showed the importance on selecting an adequate surface functional group in order to obtain silver nanoparticles filling the pores of MCM-41. (C) 2015 Elsevier Inc. All rights reserved.Sao Paulo Research foundation (FAPESP)National Counsel of Technological and Scientific Development (CNPq)Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Lab Mat Hibridos, Diadema, SP, BrazilUniv Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Lab Mat Hibridos, Diadema, SP, BrazilFAPESP: 2011/50318-1CNPq: 483878/2011-1Web of Scienc