Uniform sized (20 nm) silver nanoparticles (Ag NPs) have been decorated on the surface of mesoporous silica flakes (MSF) through a simple chemical route and characterized by powder x-ray diffraction (PXRD), BET adsorption isotherm, FTIR, TEM, UV-vis spectroscopy. The material (MSF-Ag) has been used in several purposes of water purification such as bactericides, antifouling agent, and catalyst. It shows good antibacterial activity against both Gram positive (S. aureus) and gram negative (E. coli) bacteria. The surface coated with mesoporous silica/silver (MSF-Ag) nanocomposite does not allow bacteria to grow over it under static aquatic condition. It also shows excellent catalytic property towards the reduction of dye by NaBH4. This report describes an efficient and simple technique to synthesize MSF-Ag nanocomposite which has been exploited to show bactericidal, antifouling and dye degradation properties in water with the object of drinking water purification. (C) 2017 Elsevier Ltd. All rights reserved.