Investigation of P-Type Cement Paste Production Through OH− Ion Removal by Organic Acid Impregnation for Thermoelectric Energy Harvesting

Cement-based materials are reliable materials that guarantee high efficiency and high performance and are one of the important materials for the civil engineering industries. It is an era in which carbon neutrality and energy efficiency are emphasized, and electric energy production is currently being challenged even in cement paste. At this time, the most difficult part is the process of efficiently manufacturing a positive type of P-type cement paste. In this study, a P-type cement paste impregnated with an acidic solution to remove the OH^- ions was prepared, and the Seebeck coefficient was obtained to confirm its electrical production capacity. In the case of cement, specimens impregnated with acetic acid and impregnated with undiluted solution for 48 h showed the highest value at 1270 µV/K, and those impregnated with pure lemon juice showed the highest value at 1220 µV/K. It is estimated that the compressive strength of the cement paste impregnated with pure lemon juice is about 10-40% greater than that of the cement paste impregnated with acetic acid, so the condition for producing the optimal P-type cement paste is to impregnate the pure lemon juice in a solution diluted to 20% for 48 h. This study provides the possibility of manufacturing P-type cement paste with optimal performance and manufacturing electric production cement using the Peltier effect in the future.