RESUMO
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.
