Nanosheets g-C3N4 has been synthesized from the bulk form (bulk g-C3N4) with a polymerization of Dicyandiamine DCD (NH2C(=NH)NHCN, Aldrich, 99%) by the following thermal treatment under N2 flux: heating (1 °C min -1 ) to a selected temperature of 550 °C, the isothermal step for 4 hours followed by cooling to room temperature (10 °C min -1 ). The synthesis was carried out in a partially closed alumina crucible. The thermal exfoliated catalyst (nanosheets) was prepared by heating to a selected temperature of 500 °C with an isothermal step for 2h the bulk g-C3N4 in air. The Cs2AgBiCl6/nanosheets g-C3N4 composite has been synthesized dissolving a stoichiometric ratio of the precursor salts AgCl (Aldrich 99%), BiCl3