Sodium Cation Substitution in Sr2KTa5O15 toward Enhancement of Photocatalytic Conversion of CO2 Using H2O as an Electron Donor.

Abstract

The K and Sr cations (K+ and Sr2+) in a Sr2KTa5O15 photocatalyst were found to be easily substituted by Na cations (Na+) to form SrxKyNazTa5O15 by a facile one-pot flux method using a mixture of potassium chloride (KCl) and sodium chloride (NaCl). SrxKyNazTa5O15 fabricated using a mixture of KCl and NaCl with a Ag cocatalyst showed enhanced photocatalytic activity without apparent change in selectivity toward CO for the photocatalytic conversion of CO2 using H2O. The present study demonstrates that the flux treatment significantly affected the phase, morphology, band gap, and surface Sr composition of the catalyst owing to the substitution of K+ and Sr2+ for Na+. The stability and durability of the catalyst were also enhanced as compared to those of the photocatalyst fabricated using only KCl flux due to more stable Ag on the surface of SrxKyNazTa5O15.