Kim Ki Beom, Sohn Myung Sung, Min Sunhong, Yoon Ji-Wook, Park Jin-Sung, Li Ju, Moon Young Kook, Kang Yun Chan
Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea.
Department of Information Materials Engineering, Division of Advanced Materials Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea.
Small. 2024 Aug;20(31):e2308963. doi: 10.1002/smll.202308963. Epub 2024 Mar 10.
The precise and reversible detection of hydrogen sulfide (HS) at high humidity condition, a malodorous and harmful volatile sulfur compound, is essential for the self-assessment of oral diseases, halitosis, and asthma. However, the selective and reversible detection of trace concentrations of HS (≈0.1 ppm) in high humidity conditions (exhaled breath) is challenging because of irreversible HS adsorption/desorption at the surface of chemiresistors. The study reports the synthesis of Fe-doped CuO hollow spheres as HS gas-sensing materials via spray pyrolysis. 4 at.% of Fe-doped CuO hollow spheres exhibit high selectivity (response ratio ≥ 34.4) over interference gas (ethanol, 1 ppm) and reversible sensing characteristics (100% recovery) to 0.1 ppm of HS under high humidity (relative humidity 80%) at 175 °C. The effect of multi-valent transition metal ion doping into CuO on sensor reversibility is confirmed through the enhancement of recovery kinetics by doping 4 at.% of Ti- or Nb ions into CuO sensors. Mechanistic details of these excellent HS sensing characteristics are also investigated by analyzing the redox reactions and the catalytic activity change of the Fe-doped CuO sensing materials. The selective and reversible detection of HS using the Fe-doped CuO sensor suggested in this work opens a new possibility for halitosis self-monitoring.
硫化氢（HS）是一种有恶臭且有害的挥发性硫化合物，在高湿度条件下对其进行精确且可逆的检测，对于口腔疾病、口臭和哮喘的自我评估至关重要。然而，在高湿度条件（呼出气体）下选择性且可逆地检测痕量浓度的HS（≈0.1 ppm）具有挑战性，因为化学电阻器表面存在不可逆的HS吸附/解吸现象。该研究报告了通过喷雾热解合成铁掺杂的CuO空心球作为HS气敏材料。4 at.%的铁掺杂CuO空心球对干扰气体（乙醇，1 ppm）表现出高选择性（响应比≥34.4），并且在175 °C的高湿度（相对湿度80%）条件下对0.1 ppm的HS具有可逆传感特性（100%恢复）。通过向CuO传感器中掺杂4 at.%的Ti或Nb离子来增强恢复动力学，证实了多价过渡金属离子掺杂到CuO中对传感器可逆性的影响。还通过分析铁掺杂CuO传感材料的氧化还原反应和催化活性变化，研究了这些优异的HS传感特性的机理细节。这项工作中提出的使用铁掺杂CuO传感器对HS进行选择性且可逆的检测，为口臭自我监测开辟了新的可能性。
