Abstract

Cement-based composites with thermoelectric effect have important application prospects in alleviating urban heat island effect, low-energy snow and ice melting on winter roads, and low-cost scale energy conversion and harvesting. Great progress has been made in the study of the thermoelectric properties of cement-based composites enhanced with carbon materials, and the addition of carbon materials increases the electrical conductivity of cement-based composites, but easily decreases the Seebeck coefficient. Reduced graphene oxide (RGO) by Cl₂/HNO₃ pretreatment increased the electrical conductivity of cement-based composites while also improving the Seebeck coefficient of cement-based composites, which was attributed to the increased content of RGO defects, which increased the effective mass of carriers, thus enhancing the Seebeck effect of cement-based composites and improving the thermoelectric properties of cement-based composites. When the Cl₂ pretreatment RGO content was 5.0wt%, the electrical conductivity of the cement-based composites was 1.54 S/cm, the Seebeck coefficient was −56.61 μV/°C and the ZT_max value of 1.08 × 10⁻⁴ was achieved, with average output power and thermoelectric conversion efficiency of 2.91 × 10⁻² mW/m² and 3.79 × 10⁻⁶. The cement-based composites prepared by Cl₂ pretreatment of RGO achieved the highest ZT at the same carbon material content.

摘要

具有热电效应的水泥基复合材料在缓解城市热岛效应、冬季道路低能量融雪融冰、低成本规模能量转换与收集等方面具有重要的应用前景。碳材料增强水泥基复合材料的热电性能研究取得了很大进展，碳材料的加入提高了水泥基复合材料的电导率，但容易降低塞贝克系数。Cl ₂ /HNO ₃还原氧化石墨烯 (RGO)预处理提高了水泥基复合材料的电导率，同时也提高了水泥基复合材料的塞贝克系数，这是由于增加了RGO缺陷的含量，增加了载体的有效质量，从而增强了水泥基复合材料的塞贝克效应提高水泥基复合材料的热电性能。当氯₂预处理RGO含量为5.0重量％时，水泥基复合材料的电导率为1.54 S / cm时，塞贝克系数为-56.61μV/℃和ZT_最大的1.08×10值^-4达到, 平均输出功率和热电转换效率分别为 2.91 × 10 ^-2  mW/m ²和 3.79 × 10^－6．在相同的碳材料含量下，通过Cl ₂预处理RGO制备的水泥基复合材料获得了最高的ZT。