A Z-scheme Cu₂O/WO₃ heterojunction for production of renewable hydrocarbon fuel from carbon dioxide

Utilization of a green-house gas CO₂ has a vital scope in the energy and synthesis of bulk chemicals. However, CO₂ has the limitations in synthetic chemistry because of the thermodynamic stability and un-reactivity of the CO₂ molecule. The combination of the copper and tungsten oxides established the interaction between them. It demonstrated in the high-resolution transmission electron microscopy (HR-TEM) images of Cu/W heterojunction formed, which proved as an efficient catalytic system to reduce carbon dioxide into a high yield of the renewable hydrocarbon fuel under visible-irradiation. The doping of 15 wt% of copper (II) oxide on tungsten oxide performed the best amongst all the synthesized photocatalysts, which improved the harvesting of visible light as well as enhanced the efficiency for CO₂ reduction under the reaction conditions. The improved photocatalytic activity of the heterojunction was caused by enhancement in separation and transfer of the photogenerated electron-hole pairs at the interface between copper and tungsten heterojunction investigated by the photoluminescence (PL) spectroscopy. Also, the activity of the heterojunction retained up to several runs of reaction without the marginal leaching of copper content.