Fabrication and Performance Study of a Resistive Humidity Sensor Based on ZIF-8-Derived Carbon

Abstract

Here is the English translation of the provided abstract, maintaining an academic and technical tone suitable for a research paper; With the rapid development of smart wearable devices and health monitoring technologies, flexible humidity sensors featuring high sensitivity, a wide detection range, and low hysteresis have become a research focus. Conventional humidity sensors are limited by rigid substrates, low sensitivity, poor stability, and significant temperature drift, making them inadequate for wearable detection requirements. In this study, ZIF-8 was employed as a precursor to successfully prepare ZIF-8-derived porous carbon humidity-sensitive materials through solution stirring, high-temperature heat treatment, and acid-washing modification. A flexible resistive humidity sensor was constructed on a flexible interdigital electrode via drop-coating. The effects of modification conditions (acid type, acid concentration, and acid-washing duration) on the material’s microstructure, defect density, specific surface area, and humidity-sensing performance were systematically investigated. The optimal preparation parameters were determined to be heat treatment at 800°C followed by acid washing with 2 mol/L sulfuric acid at 80°C for 6 h. The resulting ZIF8@800-H 2 SO 4 -2M sensor exhibited outstanding humidity‑sensing performance, including a detection range of 11%RH to 98%RH, a sensitivity of 1.10 /% RH, a hysteresis as low as 4.30% RH, a response time of 54.82 s, and a recovery time of 25.21 s. Furthermore, the sensor demonstrated excellent repeatability (deviation < 8.2%), long‑term stability, and mechanical bending stability. The sensor can accurately monitor human respiratory signals and achieve non‑contact palm humidity perception, indicating broad application potential in wearable health monitoring and non‑contact human-machine interaction. 随着智能可穿戴设备与健康监测技术的快速发展，具备高灵敏度、宽检测范围、低湿滞特性的柔性湿度传感器成为研究热点。传统湿度传感器受刚性基底、灵敏度低、稳定性差、温漂严重等问题限制，难以满足可穿戴检测需求。本研究以ZIF-8为前驱体，通过溶液搅拌、高温热处理及酸洗改性工艺，成功制备ZIF-8衍生多孔碳湿敏材料。采用滴涂法在柔性叉指电极上构筑柔性电阻式湿度传感器，系统探究改性条件（酸种类、酸洗浓度、酸洗时间）对材料微观结构、缺陷密度、比表面积及湿敏性能的影响，确定最优制备工艺：800°C高温热处理，80°C条件下采用2mol/L硫酸酸洗6h。所制备的ZIF8@800-H 2 SO 4 -2M传感器展现出优异的湿敏性能，检测范围达11%RH~98%RH，灵敏度为1.10/%RH，湿滞仅4.30%RH，响应时间54.82s，恢复时间25.21s。同时具备优异的重复性（重复性偏差<8.2%）、长期稳定性与机械弯曲稳定性。该传感器可精准监测人体呼吸信号，实现非接触式手掌湿度感知，在可穿戴健康监测、非接触人机交互等领域具有广阔应用潜力。