Ionic thermoelectric (i-TE) hydrogels have a high thermal energy utilization rate for low-grade heat, presenting a renewable energy supply option for sustainable global development. Conventional i-TE materials need to be conductive, stable and environmentally friendly, which remains a challenge today. This study presents a highly temperature-sensitive i-TE hydrogel with negative Seebeck coefficient, self-healing properties and conductive for photothermoelectric (PTE) conversion and non-contact sensing. The prepared PSFC-0.5 hydrogel exhibits a negative Seebeck coefficient and features a dual-crosslinked structure of polyacrylamide (PAM) and sodium alginate (SA), which provides the hydrogel with good mechanical strength (>2.7 kPa) and tensile properties (>1300 %). Photothermal (PT) conversion properties is effectively enhanced by combining carbon black/multi-walled carbon nanotubes (CB/MWCNTs) PT materials, and the addition of FeCl₃ provides anions and cations for ionic diffusion. Under a 5 K temperature gradient, the optimized Seebeck coefficient was measured to be −2.01 mV·K⁻¹ and the conductivity was approximately 1.70 mS·cm⁻¹. Moreover, reversible hydrogen bonding interactions provides ionic hydrogels with good mechanical strength and self-healing capabilities. Due to the high sensitivity of PSFC-0.5 hydrogel to temperature, it can be effectively utilized in the field of non-contact sensing for the precise detection of temperature signals. This study presents an effective method for fabricating hydrogels that exhibit exceptional toughness and electric properties, demonstrating its significant potential for applications in PTE conversion and non-contact sensing technologies.

中文翻译：

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具有负塞贝克系数、自愈性和对温度高度敏感的导电离子热电水凝胶，适用于光电热电转换和非接触式传感装置


离子热电 （i-TE） 水凝胶对低品位热具有很高的热能利用率，为全球可持续发展提供了可再生能源供应选择。传统的 i-TE 材料需要导电、稳定和环保，这在当今仍然是一个挑战。本研究提出了一种对温度高度敏感的 i-TE 水凝胶，具有负塞贝克系数、自愈特性和导电性，可用于光热电 （PTE） 转换和非接触式传感。制备的 PSFC-0.5 水凝胶表现出负塞贝克系数，并具有聚丙烯酰胺 （PAM） 和海藻酸钠 （SA） 的双交联结构，使水凝胶具有良好的机械强度 （>2.7 kPa） 和拉伸性能 （>1300 %）。通过组合炭黑/多壁碳纳米管 （CB/MWCNT） PT 材料，可以有效增强光热 （PT） 转化性能，并且 FeCl₃ 的添加为离子扩散提供了阴离子和阳离子。在 5 K 温度梯度下，优化的塞贝克系数测得为 -2.01 mV·^K-1，电导率约为 1.70 mS·^cm-1。此外，可逆氢键相互作用使离子水凝胶具有良好的机械强度和自愈能力。由于 PSFC-0.5 水凝胶对温度的高敏感性，可以有效地用于非接触式传感领域，用于温度信号的精确检测。本研究提出了一种制造具有优异韧性和电性能的水凝胶的有效方法，证明了其在 PTE 转换和非接触式传感技术中应用的巨大潜力。