Ultrasonic-assisted exfoliation of Ca2Nb3O10 − nano-sheets

Highlights: • KCa₂Nb₃O₁₀ is converted to Ca₂Nb₃O₁₀⁻ nano-sheets using the ultrasonic-treatment. • This method has much higher exfoliation efficiency comparing to the stirring. • The process accomplished after only 12 h. • Produced Ca₂Nb₃O₁₀⁻ nano-sheets can be utilized for Cs⁺ ion decontamination. -- Abstract: Ca₂Nb₃O₁₀⁻ nano-sheets can be produced via the stirring of HCa₂Nb₃O₁₀·1.5H₂O and tetrabutylammonium hydroxide mixture, which is a time-consuming process. The aim of the present study is to propose a facile and rapid route for the Ca₂Nb₃O₁₀⁻ fabrication. KCa₂Nb₃O₁₀ was firstly synthesized via a solid-state reaction. The synthesized KCa₂Nb₃O₁₀ was then protonated and exfoliated under the ultrasonic irradiation. The results revealed that the conversion of KCa₂Nb₃O₁₀ to Ca₂Nb₃O₁₀⁻ nano-sheets, with 94% exfoliation efficiency, is achievable after only 12h of ultrasonic treatment (i.e. 6 h protonation +6h exfoliation) which is the shortest time reported so far. The ultrasonically produced Ca₂Nb₃O₁₀⁻ suspension was stable and showed the capability to be utilized for the removal of hazardous ions (i.e. Cs⁺) from the wastewater. The produced Ca₂Nb₃O₁₀⁻ nano-sheets also had smaller sizes, comparing to the nano-sheets produced via stirring method.