Bi2MoO6 Quantum Dots In Situ Grown on Reduced Graphene Oxide Layers: A Novel Electron-Rich Interface for Efficient CO2 Reduction.

Abstract

Bi2MoO6 quantum dots (BM QDs, 5 nm in diameter) are evenly in situ grown on reduced graphene oxide (rGO) layers, sensitizing the graphene with high visible light response and activity for efficient solar light-driven CO2 reduction. Under irradiation, small-sized BM QDs generate active electrons and donate them to the rGO layers. Since the formation of BM QDs and the reduction of GO are undergone simultaneously, a close connection between BM QDs and rGO enables the electron injection from excited Bi2MoO6 QDs to graphene scaffolds, and abundant electrons accommodated by the rGO layers offer an electron-rich interface for CO2 reduction. With the benefit of the improved electron extraction and transport over the BM QDs/rGO interface, 84.8 μmol g-1 of methanol and 57.5 μmol g-1 of ethanol are achieved on BM QDs/rGO in 4 h with optimal composition. The total output of alcohols over BM/rGO (142.3 μmol g-1) is 2.2 and 4.4 times that achieved on unmodified Bi2MoO6 QDs (64.0 μmol g-1) and flower-like Bi2MoO6 (32.2 μmol g-1), respectively.