Cu Nanoparticles Modified Step-Scheme Cu₂O/WO₃ Heterojunction Nanoflakes for Visible-Light-Driven Conversion of CO₂...

In this study, Cu and Cu₂O hybrid nanoparticles were synthesized onto the WO₃ nanoflake film using a one-step electrodeposition method. The critical advance is the use of a heterojunction consisting of WO₃ flakes and Cu₂O as an innovative stack design, thereby achieving excellent performance for CO₂ photoreduction with water vapor under visible light irradiation. Notably, with the modified Cu nanoparticles, the selectivity of CH₄ increased from nearly 0% to 96.7%, while that of CO fell down from 94.5% to 0%. The yields of CH₄, H₂ and O₂ reached 2.43, 0.32 and 3.45 mmol/g_cat after 24 h of visible light irradiation, respectively. The boosted photocatalytic performance primarily originated from effective charge-transfer in the heterojunction and acceleration of electron-proton transfer in the presence of Cu nanoparticles. The S-scheme charge transfer mode was further proposed by the in situ-XPS measurement. In this regard, the heterojunction construction showed great significance in the design of efficient catalysts for CO₂ photoreduction application.