Abstract A facile and green approach was developed to in-situ prepare Ag nanoparticles (AgNPs) on the TiO2. Through the (3-mercaptopropyl)trimethoxysilane (MPTMS), mono-dispersed AgNPs were loaded on TiO2 (AgNPs@MPTMS-TiO2). In the presence of NaBH4, the AgNPs@MPTMS-TiO2 displayed an ultra-high catalytic activity for 4-nitrophenol reduction, of which the apparent kinetic rate constant (kapp) reached up to 394?×?10–3?s?1. Comparing to the best previous performance (kapp?=?120?×?10–3?s?1), the obtained Ag-catalysts made a huge progress. Moreover, the catalytic activity of the AgNPs@MPTMS-TiO2 could be optimized via changing series of fabrication parameters including Ag+ precursor amount and MPTMS amount, and reaction time. Various characterization techniques including TEM, HRTEM, XPS, FT-IR and Zeta potential have been utilized to study the material morphology, valance states and surface chemistry. It revealed that the AgNPs were coordinated by MPTMS though R-S–Ag bonds, which could prohibit the AgNPs from self-aggregation. In addition, the R-S–Ag bonds favored reaction of AgNPs with BH4? and thus releasing substantial protons. Consequently, the increasing proton concentration would speed up the transformation from 4-hydroxylaminophenol to 4-aminophenol.Graphic Abstract In-situ grow Ag nanoparticles (AgNPs) on (3-mercaptopropyl)trimethoxysilane (MPTMS) modified TiO2 with characters of small size, good distribution and controllable loading. The apparent kinetic rate constant (kapp) reaches as high as 394?×?10–3?s?1.
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