Abstract: A novel solution route has been developed that after heat-treatment to 500-600° C. under inert atmosphere, yields highly porous composites of nano-sized metal (Ni) particle inclusions in ceramics (Al2O3). Metal loadings could be made from <1% to >95% Ni. The metal inclusion sizes in the Ni—Al2O3 system with the 10 atom % Ni sample were 4-7 nm, while for the 75 atom % Ni sample they were 5-8 nm. It was shown that the 10 atom % Ni sample could be used as a catalyst for the conversion of CO2 and CH4 in the temperature range 550-700° C., while higher temperatures led to growth of the Ni particles and carbon poisoning over time. The solution routes could also be deposited as thin dense films containing <10 nm Ni particles. Such films with high Ni-particle loadings deposited on aluminium substrates have shown very good solar heat absorber proficiency and provide good substrates for carbon tube growth.

Abstract: A novel solution route has been developed that after heat-treatment to 500-600° C. under inert atmosphere, yields highly porous composites of nano-sized metal (Ni) particle inclusions in ceramics (Al2O3). Metal loadings could be made from <1% to >95% Ni. The metal inclusion sizes in the Ni-Al2O3 system with the 10 atom % Ni sample were 4-7 nm, while for the 75 atom % Ni sample they were 5-8 nm. It was shown that the 10 atom % Ni sample could be used as a catalyst for the conversion of CO2 and CH4 in the temperature range 550-700° C., while higher temperatures led to growth of the Ni particles and carbon poisoning over time. The solution routes could also be deposited as thin dense films containing <10 nm Ni particles. Such films with high Ni-particle loadings deposited on aluminium substrates have shown very good solar heat absorber proficiency and provide good substrates for carbon tube growth.

Abstract: A spectral selective absorbing surface on solar collector elements has a very high solar absorbing ability, in the range of 96% to 97% and a low thermal emittance, in the order of 10%, and can be produced with high capacity in industrial scale. A reactive gas in an amount of 1 to 50 cm 3/min kW, preferably 10 cm 3/min kW, distributed in the coating zone provides that the metal layer deposed onto the receiving material partly oxidizes during the deposition, whereby a layer is obtained that comprises a grain mixture of metallic material and metal oxide, whereby 40% to 80%, preferably about 50%, of metallic material is embedded into the metal oxide closest to the receiving material. The metallic material is successively decreased to about zero at the surface of the layer by increasing the addition of oxygen at the end of the coating zone.