Platelike Ag2Nb4O11 mesocrystals: Soft chemical synthesis, formation mechanism and enhanced photocatalytic performance

The soft chemical process is a useful and unique method for the preparation and design of mesocrystals materials. The platelike Ag2Nb4O11 mesocrystals are prepared via the soft chemical topotactic reaction using the layered structure K4Nb6O17 platelike particles as precursor. The formation mechanism is investigated through tracing the evolution of structure and morphology of intermediate products during the reaction, and it contains two processes. One is the ion-exchange reaction with the interlaminar ions of layered precursor. The other is in situ topotactic structure transformation reaction of the platelike Ag3HNb6O17 into platelike Ag2Nb4O11 mesocrystals during the heat-treatment process. Moreover, the degradation of RhB over the platelike Ag2Nb4O11 mesocrystals can reach to 95.3% after the irradiation of 20 min. The enhancement of photocatalytic performance of Ag2Nb4O11 mesocrystals can be attributed to its unique morphology and exposed facet, which affect the band gap and energy band structure. (C) 2016 Elsevier B.V. All rights reserved.