Research paperHighly selective photocatalytic conversion of CO2 by water over Ag-loaded SrNb2O6 nanorods

•SrNb2O6 and Sr2Nb2O7 with regular nanostructures are synthesized by a flux method.•SrNb2O6 shows high selectivity to CO for photocatalytic reduction of CO2 by H2O.•Effect of Ag cocatalyst on photocatalytic activity and selectivity is investigated.•Mechanism for the high selectivity of SrNb2O6 nanorods is proposed.

Strontium niobates (SrNb2O6 and Sr2Nb2O7) with regular nanostructures were synthesized by a facile flux method. Ag-loaded SrNb2O6 and Sr2Nb2O7 exhibited different performances for the photocatalytic reduction of CO2 in H2O. Compared to Sr2Nb2O7 nanoflakes and SrNb2O6 nanoparticles, SrNb2O6 nanorods exhibited higher photocatalytic activity and selectivity toward CO evolution. Stoichiometric amounts of CO (51.2 μmol h−1) and H2 (1.1 μmol h−1) as the reduction products, in addition to O2 (24.8 μmol h−1) as the oxidation product, were obtained, indicating that H2O serves as an electron donor in the photocatalytic conversion of CO2. In addition, the effect of the Ag cocatalyst on the photocatalytic conversion of CO2 was investigated.

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