Ultrasonic-assisted rapid and highly efficient liquid-phase exfoliation of α-zirconium phosphate

α-zirconium phosphate (α-ZrP) was liquid phase exfoliated within 10 min using diethylene glycol amine (DGA) as the exfoliator under ultrasonic assistance. The complete exfoliation of zirconium phosphate nanosheets was confirmed by X-ray diffraction, transition electron microscope and zeta potential. To extend the application of this study, a series of amino alcohols, amino acids, alkyl amines and diols were applied to the exfoliation of α-ZrP, and the results showed that amino alcohols and basic amino acids with both basic amino and hydrophilic groups (hydroxyl and carboxyl groups) were effective exfoliating agents. It is postulated that the exfoliation process consists of two steps: guest molecule intercalation and water swelling, and both steps are significantly promoted by high-powered ultrasound. We believe that these findings contribute to a better understanding of the exfoliation process of two-dimensional materials and enable researchers to fabricate functional lamellar composites more easily. Graphical abstract