Building Physics and Environment Institute, Housing and Building National Research Center (HBRC), Dokki, Giza, 12311, Egypt.
Nanotechnology Research Center, The British University in Egypt (BUE), Suez Desert Road, El Sherouk City, Cairo, 11837, Egypt.
Sci Rep. 2023 Feb 18;13(1):2891. doi: 10.1038/s41598-023-29960-8.
Relative humidity (RH) is one of the most important factors that deserve intensive study because of its impact on many aspects of life. In this work humidity sensor based on carbon nitride / graphene quantum dots (g-C3N4/GQDs) nanocomposites have been developed. The structure, morphology and composition properties of the g-C3N4/GQDs were investigated and analyzed by XRD, HR-TEM, FTIR, UV-Vis, Raman, XPS and BET surface area. The average particle size of GQDs was estimated from XRD to be 5 nm and confirmed using HRTEM. The HRTEM images prove that the GQDs are attached to the external surface of the g-C3N4. The measured BET surface area was found to be 216 m/g, 313 m/g, and 545 m/g for GQDs, g-C3N4, and g-C3N4/GQDs respectively. The d-spacing and crystallite size were estimated from XRD and HRTEM and found in a good matching. The humidity sensing behavior of g-C3N4/GQDs was measured in a wide span of humidity from 7% up to 97% RH under different testing frequencies. The obtained results demonstrate good reversibility and fast response/recovery time. The implemented sensor exhibits a great application prospect in humidity alarm devices, automatic diaper alarms, and breath analysis, which have advantages such as strong anti-interference capability, low cost, and easy to use.
相对湿度（RH）是值得深入研究的最重要因素之一，因为它会对生活的许多方面产生影响。在这项工作中，我们开发了基于氮化碳/石墨烯量子点（g-C3N4/GQDs）纳米复合材料的湿度传感器。通过 XRD、HR-TEM、FTIR、UV-Vis、Raman、XPS 和 BET 表面积等手段对 g-C3N4/GQDs 的结构、形貌和组成特性进行了研究和分析。通过 XRD 估计 GQDs 的平均粒径为 5nm，并通过 HRTEM 进行了确认。HRTEM 图像证明 GQDs 附着在 g-C3N4 的外表面上。测量的 BET 表面积分别为 GQDs（216m/g）、g-C3N4（313m/g）和 g-C3N4/GQDs（545m/g）。从 XRD 和 HRTEM 估计了 d 间距和晶粒尺寸，并发现它们之间存在良好的匹配。在不同测试频率下，g-C3N4/GQDs 在 7%至 97%RH 的宽湿度范围内进行了湿度传感行为测量。所得到的结果表明具有良好的可逆性和快速的响应/恢复时间。所实现的传感器在湿度报警装置、自动尿布报警和呼吸分析等方面具有抗干扰能力强、成本低、使用方便等优点，具有很好的应用前景。
