Synthesis of quartz crystals supporting Ag nanoparticle powder with enhanced antibacterial properties

The commonly natural quartz stone was selected as the substrate materials for supporting Ag nanoparticles due to its high temperature resistance and low cost. The quartz crystals supporting Ag nanoparticles powder have been fabricated successfully through the silver nitrate loading on natural quartz precursors, which were obtained by a solvent evaporation process. After being calcinations, Ag nanoparticles with size of 30-50 nm were deposited on the surface of quartz matrix. Experimental studies revealed that the concentration of AgNO3 plays a pivotal role in controlling the size and agglomeration of Ag nanoparticles in final products. The optimum temperature of AgNO3 thermal-decomposing is ca. 500 °C. With increasing the concentration of Ag nanoparticles attached on quartz crystals, some Ag particles grow up, and the colors of the powder change from light yellow to brown. Antibacterial tests showed that the quartz crystals supporting Ag nanoparticle exhibit excellent antibacterial performance against E. coli, mainly attributed to the facts that the Ag nanoparticles can penetrate into the bacteria and cause the death of bacteria cells.