The relationship between photocatalytic activity and crystal structure in strontium tantalates

Three compounds, SrTa2O6, Sr4Ta2O9, and Sr5Ta4O15, were synthesized by a polymerizable complex method. Their photocatalytic activities for water splitting into H2 and O2 were tested and compared against previously published results for Sr2Ta2O7. It was found that the efficiency of the catalysts decreases in the following order: Sr2Ta2O7 >Sr5Ta4O15 > SrTa2O6 > Sr4Ta2O9. The relationship between photocatalytic activities and crystal structures is discussed.