Monolithic copper oxide aerogel via dispersed inorganic sol–gel method

To avoid the use of rare copper alkoxides, copper oxide aerogels were prepared using copper chloride, polyacrylic acid and propylene oxide via the dispersed inorganic sol–gel method, a supercritical fluid drying process and a 500 °C thermal treatment. The morphology and composition of the aerogel without thermal treatment (copper-based aerogel) and copper oxide aerogel were both characterized and analyzed. Based on studies of the gelation mechanism, it was demonstrated that polyacrylic acid guides the sol formation including providing a steric effect. Analysis of the thermal treatment process shows that the copper-based aerogel has four primary thermal reactions and the major composition of samples treated above 420 °C is monoclinic copper oxide.