Joule Heating Characteristics of Emulsion-Templated Graphene Aerogels

The Joule heating properties of an ultralight nanocarbon aerogel are investigated with a view to potential applications as energy-effi cient, local gas heater, and other systems. Thermally reduced graphene oxide (rGO) aerogels (10 mg cm −3 ) with defi ned shape are produced via emulsion-templating. Relevant material properties, including thermal conductivity, electrical conductivity and porosity, are assessed. Repeatable Joule heating up to 200 °C at comparatively low volt-ages (≈1 V) and electrical power inputs (≈2.5 W cm −3 ) is demonstrated. The steady-state core and surface temperatures are measured, analyzed and com-pared to analogous two-dimensional nanocarbon fi lm heaters. The assessment of temperature uniformity suggests that heat losses are dominated by conduc-tive and convective heat dissipation at the temperature range studied. The radial temperature gradient of an uninsulated, Joule-heated sample is analyzed to estimate the aerogel's thermal conductivity (around 0.4 W m −1 K −1 ). Fast initial Joule heating kinetics and cooling rates (up to 10 K s −1 ) are exploited for rapid and repeatable temperature cycling, important for potential applications as local gas heaters, in catalysis, and for regenerable of solid adsorbents. These princi-ples may be relevant to wide range of nanocarbon networks and applications.