Advancing the Mechanical and Thermoelectric Properties of Geopolymers for Sustainable Architectureh

Given the increasing global carbon emissions, the energy crisis, and the pressing need for sustainability, this research study focuses on thermoelectric (TE) geopolymer composites (GC) as multi-functional construction materials. The research investigates the electron and ion-driving transport mechanisms in TE of GCs, considering the influence of the Soret effect. The enhancement of TE properties through additives, including Fe₂O₃ nanoparticles, graphene nanoplatelets (GNPs), and poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate) (PEDOT:PSS), is thoroughly explored. In this study, the samples GG exhibit higher TE power factors (PF), achieving values of 0.84 µWm⁻¹K⁻². This may be attributed mainly to the higher electronic and ionic conductivity of the π-bond, along with improved Seebeck coefficients resulting from the tetrahedral geopolymeric framework. Meanwhile, this research investigates the relationship between ionic thermoelectricity and conductivity, as well as the influence of porosity on the Soret effect. It reveals that in porous materials like geopolymers, the levels of ionic and electronic conductivities are comparable. However, electronic conductivity prevails beyond the threshold of conductive additive permeation. This dual ionic-electronic regulation of TE properties underscores the significant potential of geopolymers for enhanced energy harvesting applications.