Perpustakaan Digital ITB

A scalable organic intercalant-free liquid exfoliation route to 2D nanosheets (NSs) of layered transition-metaloxides (TMOs) is developed by employing hydronium-intercalated derivatives as precursors. The replacement of interlayeralkali metal ions with larger hydronium ions via acid treatment makes possible the efficient liquid exfoliation of TMOs withoutany assistance of organic intercalant cations. Not only a weakening of interlayer electrostatic interaction upon hydroniumintercalation but also an efficient solvation of deintercalated hydronium ions via hydrogen bonding with polar solvents is mainlyresponsible for the high efficacy of hydronium-intercalated TMOs as precursors for liquid exfoliation. The nature of the solventemployed also has a profound effect on the exfoliation yield of these TMO NSs; viscosity, surface tension, density, and Hansensolubility parameter as well as the capability to solvate the exfoliated NSs and hydronium ions are crucial factors for determiningthe exfoliation efficiency of the hydronium-intercalated precursor. All the obtained Ti1?xO2, MnO2, and RuO2NSs show highlyanisotropic 2D morphologies and distinct negative surface charges with a zeta potential of?30 to?50 mV. Such distinct surfacecharges of these NSs render them versatile hybridization matrices for the synthesis of novel nanohybrids with enhancedfunctionalities. The hybridization with the liquid-exfoliated TMO NSs is quite effective in improving the photocatalytic activityof CdS and the electrode functionalities of graphene and graphene-layered double hydroxide nanohybrids. The present studyunderscores the usefulness of the present liquid exfoliation method in synthesizing organic-free TMO NSs and theirnanohybrids as well as in widening the applicationfield of exfoliated TMO NSs.