A low-cost template-free solution chemical route to highly porous nanocrystalline sponges of ZnO-EuO1.5 with 0-5 mol % Eu is presented. The process uses Zn- and Eu-acetate- nitrate and triethanolamine as precursors in methanol. After evaporation of the solvent and heating at 200 degrees C for 3 min, crystalline ZnO:Eu sponges with minor amounts of organic residues were obtained. Heating to 400 degrees C replaced the organics with carbonate, which in its turn was decomposed at temperatures below 600 degrees C, forming ZnO:Eu sponges. Samples heated to 200-1000 degrees C for 3 min were studied with XRD, SEM, TEM, TG, XPS and IR spectroscopy. The ZnO:Eu crystallite sizes could be tuned from below 10 nm for sponges prepared at 200-500 degrees C, to over 100 nm range at 900 degrees C, without sintering of the overall microstructure. XRD showed the presence of hexagonal ZnO:Eu (or at 700-1000 degrees C, ZnO:Eu and cubic Eu2O3) as the only phases present. The ZnO:Eu had slightly larger unit cell dimensions than the literature value of ZnO for samples obtained at 200-600 degrees C, while the unit cells of samples obtained at higher temperatures were quite close to the value of undoped ZnO. XPS showed that Eu was mainly in its 3+ state and well-distributed within the sponges but segregated at the ZnO sponge surface upon heating at 700-1000 degrees C, in accordance with XRD studies showing Eu2O3 formation.