One dimensional SnO₂ NRs/Fe₂O₃ NTs with dual synergistic effects for photoelectrocatalytic reduction CO₂ into...

The hydrothermal method was explored to prepare SnO₂ nanorods (SnO₂ NRs) with the special faces of (110) and (101) on the surface of Fe₂O₃ nanotubes (Fe₂O₃ NTs). According to the SEM and XRD results, the formation process of the hierarchically assembled SnO₂ NRs was deduced. The SnO₂ NRs/Fe₂O₃ NTs catalyst that had reached for 120 mins behaved the best photoelectrocatalytic properties. From the view of photocatalytic reduction, the conduction band (-0.75eV vs NHE) is negative enough to drive CO₂ reduction, and the valence band (1.82eV) is positive enough to oxidize H₂O to generate proton, and then the proton is used for CO₂ reduction. From the electrocatalytic reduction point, the net CO₂ reduction current density of the composite is 7.48 times that of Fe₂O₃ NTs at -1.1V, indicating that the electrocatalytic performance of Fe₂O₃ NTs is greatly enhanced by the introduction of 6-fold branched SnO₂ NRs. The predominant reduction product is analyzed by GC was methanol. Herein, two synergistic effects are proved according to the methanol yields, one is the synergistic effect of the photocatalytic and electrocatalytic reduction, the other is the synergistic effect between SnO₂ NRs and Fe₂O₃ NTs. The results indicated that the composite catalyst behaves excellent photoelectrocatalytic activity for CO₂ reduction.