Integrating reduced graphene oxides and PPy nanoparticles for enhanced electricity from water evaporation

Developing high-performance nanostructured materials is key to deliver the potential of hydrovoltaic technology into practical applications.As single-component materials have approached its limit in generating hydrovoltaic electricity,the development of multi-component hydrovoltaic materials has been necessary in continuously boosting the electricity output.Here,we report a hydrovoltaic material by integrating reduced graphene oxides and polypyrrole nanoparticles(rGO/PPy),where the rGO contributes improved conductivity and large specific surface area while PPy nanoparticles enable enhanced interaction with water.The device fabricated with this material generates a short-circuit current of 6μA as well as a maximum power density of over 1μW/cm3 from natural evaporation of water.And the substantial ion-PPy interaction enables robust voltage generation from evaporation of various salt solutions.Moreover,an outstanding scaling ability is demonstrated by connecting 10 devices in series that generate a sustainable voltage of up to~2.5 V,sufficing to power many commercial devices,e.g.LED bulb and LCD screen.