The invention relates to a photocatalytic carbon dioxide reduction method carried out in liquid and/or gas phase under irradiation, using a photocatalyst containing a first semiconductor, particles comprising one or more metallic-state elements M, and a second semiconductor SC, wherein the method is carried out by contacting a feedstock containing the CO2 and at least one sacrificial compound with the photocatalyst, then irradiating the photocatalyst such that the CO2 is reduced, and oxidising the sacrificial compound in order to produce an effluent containing at least in part C1 or above carbon molecules other than CO2.