Drop Solution Calorimetric Studies of Interface Enthalpy of Cubic Silver (I) Oxide (Ag2O) Nanocrystals

The nanoscale, cubic silver (I) oxide (Ag2O.nH2O) with different particles sizes and surface areas were synthesized by a wet chemical technique. The prepared crystallite size ranges were from (33.3±0.3 to 39.4±0.4 nm). Interface areas were estimated by comparing the surface areas measured by N2 adsorption to the crystallite sizes refined from X-ray diffraction data. The interface enthalpy of Ag2O.nH2O nanocrystal was measured using isothermal acid solution calorimetry in 25%HNO3 at 26°C. The interface enthalpy was verified by utilizing thermodynamic cycle. The enthalpies of drop solution (ΔHds) for Ag2O.nH2O are exothermic and range from (-62.228±0.197) to (-64.025±0.434 kJ/mol), while its interface enthalpy is (0.842±0.508 J/m2). This work provides the first calorimetric measurement of the interface enthalpy of nanocrystalline silver (I) oxide (Ag2O.nH2O).