Chellamuthu Poundoss, Savarimuthu Kirubaveni, Alsath M Gulam Nabi, R Krishnamoorthy, T Yuvaraj, Bajaj Mohit, Shabaz Mohammad
Centre for Smart Energy Systems, Chennai Institute of Technology, Chennai, 600069, India.
Department of Electronics and Communication Engineering, College of Engineering, Anna University, Guindy, Chennai, Tamil Nadu, 600025, India.
Sci Rep. 2025 Aug 20;15(1):30628. doi: 10.1038/s41598-025-12499-1.
This research investigates the fabrication of surfactant-mixed tin oxide (SnO) nanostructured thin films on a fluorine-doped tin oxide (FTO) substrate via hydrothermal synthesis, focusing on their structural, morphological, optical, and electrical properties for sensor applications. To examine the effect of surfactant concentration, cetyltrimethylammonium bromide (CTAB) was incorporated at varying weight percentages (0%, 6%, 11%, 16%, and 20%), resulting in five distinct sensor samples, labelled SnO-1, SnO-2, SnO-3, SnO-4, and SnO-5, respectively. X-Ray Diffraction (XRD) analysis confirms a tunable crystallite size from 12.2 nm (SnO-1) to 4.8 nm (SnO-5), with a corresponding increase in defect density (0.0067 nm to 0.0434 nm), making SnO-5 highly sensitive for gas sensing and humidity detection. Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) analyses reveal a structural transformation from aggregated grains in pure SnO to a highly interconnected, flower-like morphology in SnO-5, increasing surface area and enhancing adsorption properties. Brunauer-Emmett-Teller (BET) surface area measurements show a significant increase from 53.15 m/g (SnO-1) to 132.70 m/g (SnO-5), with pore volume rising from 0.245 cm3/g to 0.405 cm3/g, suggesting improved catalytic and electrochemical activity for energy storage and supercapacitors. Fourier Transform Infrared Spectroscopy (FT-IR) spectra confirm functional groups (O-H, C=O, O-Sn-O) essential for gas and biomolecular interactions, making the material suitable for biomedical and environmental monitoring applications. Optical studies via UV-Vis spectroscopy (Ultraviolet-Visible) indicate a tunable band gap correlating with surface modifications, beneficial for optoelectronic and UV sensor applications. Current-Voltage (J-V) measurements reveal a drastic reduction in cut-in voltage from 0.405 V (SnO-1) to 0.071 V (SnO-5), demonstrating superior charge transport, which is useful in resistive-type gas sensors and electronic devices. The Electro-chemical Impedance Spectroscopy (EIS) study further supports this by showing a lower charge transfer resistance (R = 1250 Ω) and increased inter-facial capacitance (C = 159.2 µF) in SnO-5, making it an excellent candidate for solid-state super capacitors and bio-sensing applications. These findings confirm that surfactant-modified SnO nanostructures are highly adaptable for gas sensing, environmental monitoring, biomedical applications, and energy storage technologies.
本研究通过水热合成法，研究了在氟掺杂氧化锡（FTO）衬底上制备表面活性剂混合的氧化锡（SnO）纳米结构薄膜，重点关注其用于传感器应用的结构、形态、光学和电学性质。为了研究表面活性剂浓度的影响，以不同重量百分比（0%、6%、11%、16%和20%）掺入十六烷基三甲基溴化铵（CTAB），得到五个不同的传感器样品，分别标记为SnO-1、SnO-2、SnO-3、SnO-4和SnO-5。X射线衍射（XRD）分析证实，微晶尺寸可从12.2纳米（SnO-1）调至4.8纳米（SnO-5），缺陷密度相应增加（从0.0067纳米至0.0434纳米），使得SnO-5对气体传感和湿度检测具有高灵敏度。场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）分析表明，结构从纯SnO中的聚集颗粒转变为SnO-5中高度互连的花状形态，增加了表面积并增强了吸附性能。布鲁诺尔-埃米特-泰勒（BET）表面积测量显示，表面积从53.15平方米/克（SnO-1）显著增加到132.70平方米/克（SnO-5），孔体积从0.245立方厘米/克增加到0.405立方厘米/克，表明其在能量存储和超级电容器方面的催化和电化学活性得到改善。傅里叶变换红外光谱（FT-IR）光谱证实了气体和生物分子相互作用所必需的官能团（O-H、C=O、O-Sn-O），使该材料适用于生物医学和环境监测应用。通过紫外-可见光谱（UV-Vis）进行的光学研究表明，带隙可调且与表面改性相关，有利于光电子和紫外传感器应用。电流-电压（J-V）测量显示，开启电压从0.405伏（SnO-1）急剧降至0.071伏（SnO-5），表明其具有优异的电荷传输性能，这在电阻型气体传感器和电子器件中很有用。电化学阻抗谱（EIS）研究进一步支持了这一点，该研究表明SnO-5中的电荷转移电阻较低（R = 1250 Ω）且界面电容增加（C = 159.2 μF），使其成为固态超级电容器和生物传感应用的极佳候选材料。这些发现证实，表面活性剂改性的SnO纳米结构非常适合用于气体传感、环境监测、生物医学应用和能量存储技术。
