Mesostructured CeO₂/g-C₃N₄ nanocomposites: Remarkably enhanced photocatalytic activity for CO₂ reduction by mutual component activations

CO₂ is highly stable and therefore extremely difficult to be reduced at room temperature. Herein, mesostructured CeO₂/graphite carbon nitride (m-CeO₂/g-C₃N₄) was designed and synthesized through a hard-template route. The heterogeneous nanocomposites showed greatly enhanced response to solar light, promoted charge carrier separation and transfer efficiency. Consequently, their CO₂ photoreduction performance has been remarkably enhanced. Maximum CO and CH₄ yields of 0.590 and 0.694μmol, respectively, have been obtained from the CO₂ reduction after one hour irradiation at room temperature on 50mg nanocomposite photocatalyst. Different from common g-C₃N₄-based composites in which the additional component only plays a role of electron sink in electron-hole separation, a synergetic effect of mutual activations between the two components is proposed, which is featured with g-C₃N₄ activation due to significantly promoted separation of photo-generated carriers under Xenon lamp irradiation, and CeO₂ activation via the reduction of Ce⁴⁺ to Ce³⁺ by the trapped electrons.