Microwave-assisted hydrothermal synthesis of perovskite NaTaO3 nanocrystals and their photocatalytic properties

A fast and facile process for the preparation of perovskite NaTaO3 nanocrystals with Ta2O5 and NaOH as starting materials by a microwave-assisted hydrothermal (MHT) technique is reported. By pretreating the Ta2O5 powder by ball milling, pure-phase NaTaO3 can be synthesized under quite mild conditions through the formation of an intermediate pyrochlore Na2Ta2O6 phase, while much longer times are required in a conventional hydrothermal (CHT) process. After loading with NiO co-catalyst, the NaTaO3 nanocrystals prepared by the MHT method showed photocatalytic activity for overall water splitting more than two times greater than those prepared under CHT conditions.