High-efficiency synergistic conversion of CO2 to methanol using Fe2O3 nanotubes modified with double-layer Cu2O spheres

Abstract

Cuprous oxide/hematite nanotubes (Cu₂O/Fe₂O₃NTs) were prepared by a potentiostatic electrodeposited method, in which different structured Cu₂O materials were modified onto Fe₂O₃ NTs surface. Among them, the material with double-layer Cu₂O spheres (Cu₂O/Fe₂O₃ NTs-30) showed excellent photoelectrocatalytic (PEC) properties with a suitable energy band gap (1.96 eV) and a smaller overpotential (0.18 V). Furthermore, Cu₂O/Fe₂O₃ NTs-30 showed two types of synergisms in the PEC reduction of CO₂: (i) between electrocatalysis and photocatalysis and (ii) between Cu₂O and Fe₂O₃NTs. The faradaic efficiency and methanol yield reached 93% and 4.94 mmol L⁻¹ cm⁻² after 6 h, respectively.