Influence of Fe2O3 on the absorptivity of in situ synthesized solar high-temperature absorbing and storing integrated mullite-based ceramics.

Solar energy absorption and storage of integrated ceramic materials is both the absorption of sunlight and storage of sunlight into thermal energy functional materials. In this paper, the effect of Fe 2 O 3 on the solar absorptivity, thermal storage properties, sintering temperature, and physical properties of mullite-based thermal storage ceramics was investigated. The results show that the absorptivity and thermal storage density of the sample AF4 (Bauxite:50 wt%, Clay:50 wt%, Fe 2 O 3 :11 wt%) after sintering at 1420 °C are 87.2% and 1116.5 kJ kg−1, respectively; and the unit volume of the AF4 sample can provide the power grid with 918.01 kW h of electricity, save 112.91 kg of coal, and reduce 361.33 kg of CO 2 emission. This study systematically elucidated the mechanism of the enhancement of sample absorption caused by Fe3+ doping-induced changes in substrate color, reduction in material forbidden bandwidth, and lattice anharmonic vibration effect, in addition to comprehensively evaluating the feasibility of the optimal AF4 sample for use in solar energy absorbing and storing integrated ceramic materials. [ABSTRACT FROM AUTHOR]