Cuprous Oxide‐Based Carbonaceous Composite Materials: Theoretical Studies, Synthesis, Properties, and Applications in Energy and Environment

Cuprous oxide (Cu 2 O), a low‐cost p‐type semiconductor with narrow bandgap (~2.0–2.2 eV) and strong visible‐light absorption, is a promising candidate of energy and environmental applications. The integration of carbon materials with Cu 2 O, which is an effective strategy, has been studied by searching past research to overcome the inherent limitations Cu 2 O. This study comprehensively examines the mechanisms of how the carbon materials enhance the properties of cuprous oxide and their design principles, synthesis methods and structural property relationships between these two material types by considering their material, electrical and electrochemical properties while focusing future research paths in this emerging. Theoretical studies followed by density functional theory (DFT) provide deep insights into electronic structure at Cu 2 O–carbon interface, adsorption energies, bandgaps, density of states (DOS), charge distributions to study the synergy between these two material types. The review provides both theoretical guidance and experimental progress to design a next‐generation Cu 2 O–carbon composites for sustainable energy and environmental field.