Solid waste-based multifunctional material preparation and analysis of carbon sequestration-thermal storage-photothermal

The inherent abundance of CaO, silicate, and Fe3O4 in solid waste presents an opportunity for its multifunctional resource utilization, positioning it as a pivotal component for developing a circular economy. CaO is used for capturing and sequestering carbon dioxide; silicate is used to prepare phase-change material carriers; and Fe3O4 is used for photothermal conversion. Therefore, this work proposes a strategy for multifunctional utilization of solid waste. In this work, the first step is to use CaO in industrial solid waste to sequester carbon dioxide. Then, carbonized solid waste and expanded graphite encapsulated paraffin wax were used to prepare composite phase change materials that could be used for photothermal conversion. The results show that the carbon sequestration efficiency of carbon dioxide from solid waste reached 0.419 g CO2/g. The prepared composite phase change material exhibited excellent anti-leakage performance, with only 1 % leakage observed after 100 cycles. The energy storage density of the sample was 99.56 J/g. Its photothermal conversion efficiency reached 81.07 % under the combined effect of expanded graphite and Fe3O4. This realizes the multifunctional and efficient utilization of solid waste resources for CO2 sequestration, thermal energy storage, and photothermal conversion.