A TiO2-graphene-silver hybrid nanocomposite and a method of preparing the TiO2-graphene-silver hybrid nanocomposite is disclosed. The TiO2-graphene-silver hybrid nanocomposite at an average particle size ranging from 12-15 nanometers and having a surface area of 140.5 m2/g includes titanium oxide, graphene oxide and silver, the silver ranging from about 2 weight % to 10 weight %. The method of preparation includes introducing sol gel to a microwave irradiation to prepare an irradiated sample of TiO2-graphene oxide sample, wherein the sol gel includes TiO2 containing gel along with graphene containing sol, followed by adding AgNO3 solution to the TiO2-graphene oxide sample for preparing a TiO2-graphene-silver hybrid suspension. The TiO2-graphene-silver hybrid suspension undergoes microwave irradiation to prepare dried TiO2-graphene-silver hybrid composite.