Influence of industrial solid wastes on the thermoelectric behavior of cement-based thermoelectric materials

Le résumé fourni par la source

Cement-based thermoelectric (TE) materials hold great promise for harvesting low-grade heat and enabling self-powered sensors in smart infrastructure. However, their widespread application is hindered by limited power output and the high cost of conventional functional fillers. To address these challenges, this study explores a low-cost and sustainable approach by incorporating three types of industrial solid wastes—red mud (RM), hematite powder (HP) and steel slag powder (SSP)—as functional fillers in multi-walled carbon nanotube-cement composites. Among these, RM markedly enhanced the Seebeck coefficient, achieving a peak value of 2544.42 μV·K−1 at 6 wt% content, which led to a 46-fold increase in the dimensionless figure of merit (ZT) compared to the reference sample. In contrast, HP and SSP primarily improved the microstructural densification and mechanical strength, with only marginal contributions to TE performance. Microstructural analyses indicated that the oxide components in the wastes optimized the pore structure and promoted matrix densification, thereby significantly enhancing the compressive strength. Furthermore, leaching tests confirmed that the incorporated solid wastes did not introduce significant environmental risks. This work demonstrates a feasible pathway of repurposing non-treated industrial solid wastes into high-value TE fillers, providing valuable insights for the development of cost-effective, high-performance and eco-friendly TE building materials.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.