Zirconium dioxide/calcium silicate/graphitic carbon nitride nanocomposite and method of use as a photocatalyst

A method of water purification, comprising:

• mixing contaminated water comprising one or more pollutants with a zirconium dioxide/calcium silicate/graphitic carbon nitride (ZrO2/CaSiO3/g-C3N4) nanocomposite material to form a reaction mixture;
• exposing the reaction mixture to light;
• and
• removing the nanocomposite material to form purified water,
• wherein the nanocomposite material comprises spherical metal oxide nanoparticles comprising a ZrO2 phase and a CaSiO3 phase dispersed on a matrix of g-C3N4 nanosheets,
• wherein the spherical metal oxide nanoparticles have an average particle diameter in a range from 2 to 25 nanometer (nm),
• wherein the nanocomposite material has a band gap energy in a range from 1.5 to 4 electron volt (eV), and
• wherein the nanocomposite material catalyzes the photodegradation of the one or more pollutants,
• wherein the nanocomposite material is in the form of particles having a trimodal pore size distribution with average pore diameters maximized at 6.2, 9.53, and 17.2 nm.