Recent advancements in thermoelectric materials have the potential to transform energy efficiency in the construction sector, particularly through the novel research conducted by Xiaosong Tang and his team at the Institute of Materials Research and Engineering (IMRE), Singapore. Their study, published in the journal Energy Material Advances, delves into the enhancement of thermoelectric properties in zinc oxide (ZnO) composites by doping them with calcium oxide (CaO).
Traditionally, the use of active metal oxides in thermoelectric applications has been limited due to concerns about their stability, particularly regarding surface hydration. However, Tang’s research challenges this notion, demonstrating that Ca-doped ZnO composites not only exhibit improved electrical conductivity but also maintain their thermoelectric performance under varying conditions. “This work opens up new avenues for the application of ZnO-based thermoelectric materials, especially in environments where stability has been a concern,” Tang noted.
In their experiments, the team synthesized Ca-doped ZnO composites using the spark plasma sintering method, varying the concentration of CaO nanoparticles from 0.05 to 0.2 mol. %. They found that the electrical conductivity of these composites increased significantly, reaching an impressive 650 S cm−1 with just 0.1 mol. % of CaO. This enhancement is attributed to the formation of conductive calcium hydroxide (Ca(OH)2) due to the hygroscopic nature of CaO.
Interestingly, while the conductivity was reduced after high-temperature annealing, the Seebeck coefficient remained stable, suggesting that the substitution of Zn2+ ions with Ca2+ ions plays a crucial role in maintaining the thermoelectric properties. The research also revealed that the crystal structure of the doped composites closely resembles that of pure ZnO, ensuring compatibility in various applications.
The implications of this research are profound for the construction industry, where energy efficiency is paramount. With a peak thermoelectric figure of merit (ZT) of approximately 0.043 at 723 K—eight times greater than that of undoped ZnO—these materials could be integrated into building designs to harness waste heat from HVAC systems or other sources, converting it into usable electrical energy. This could significantly reduce energy costs and improve the sustainability of construction projects.
As the construction sector increasingly seeks innovative solutions to enhance energy efficiency, the findings from Tang’s team represent a promising step forward. “The potential applications of CaO-doped ZnO in energy systems are vast, and we are excited to see how these materials can be utilized in real-world settings,” Tang expressed, emphasizing the commercial viability of their research.
The study underscores the importance of continued exploration into novel thermoelectric materials, which could lead to significant advancements in energy management within the construction industry. As the sector evolves, integrating such innovative materials could pave the way for smarter, more sustainable buildings. For more information on their work, you can visit IMRE.
