The application of N-doped carbon nanosheets, with and without embedded carbon dots, as active materials for the room temperature chemoresistive detection of methanol and/or ethanol is presented. The new carbons were made by converting 0D N-doped carbon dots (NCDs) to 2D nitrogen-doped carbon nanosheets by heat treatment (200–700 °C). The nanosheets exhibited a lateral size of ∼3 μm and a thickness of ∼12 nm at the highest annealing temperature. Both Raman and TEM analyses showed morphological transitions of the dots to the sheets, whilst XPS analysis revealed transformation of the N-bonding states with increasing temperature. PDF analysis confirmed the presence of defective carbon sheets. Room temperature screening of the chemical vapours of two alcohols (methanol and ethanol), revealed that the structure and the type of N-configuration influenced the detection of the chemical vapours. For instance, the lateral size of the nanosheets and the high charge density N-configurations promoted detection of both methanol and ethanol vapours at good sensitivity (−16.8 × 10⁻⁵ ppm⁻¹_EtOH and 1.2 × 10⁻⁵ ppm⁻¹_MeOH) and low LoD (∼44 ppm_EtOH and ∼30.3 ppm_MeOH) values. The study showed that the composite nature as well as the large basal area of the carbon nanosheets enabled generation of adequate defective sites that facilitated easy adsorption of the VOC analyte molecules, thereby eliminating the need to use conducting polymers or the formation of porous molecular frameworks for the alcohol detection.

中文翻译：

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从 0D 到 2D：用于检测酒精基化学蒸气的 N 掺杂碳纳米片

介绍了具有和不具有嵌入碳点的 N 掺杂碳纳米片作为活性材料在甲醇和/或乙醇的室温化学电阻检测中的应用。新碳是通过热处理（200-700°C）将 0D N 掺杂碳点（NCD）转化为 2D 氮掺杂碳纳米片制成的。在最高退火温度下，纳米片的横向尺寸约为 3 μm，厚度约为 12 nm。拉曼和 TEM 分析都显示了点到薄片的形态转变，而 XPS 分析显示随着温度的升高 N 键态的转变。PDF 分析证实存在有缺陷的碳片。两种醇（甲醇和乙醇）的化学蒸气的室温筛选，揭示了N-构型的结构和类型影响了化学蒸气的检测。例如，纳米片的横向尺寸和高电荷密度 N 构型促进了以良好的灵敏度（-16.8 × 10^-5 ppm ^-1 _EtOH和 1.2 × 10 ^-5 ppm ^-1 _MeOH）和低 LoD（～44 ppm _EtOH和～30.3 ppm _MeOH）值。研究表明，碳纳米片的复合性质以及大的基底面积能够产生足够的缺陷位点，从而促进 VOC 分析物分子的轻松吸附，从而消除了使用导电聚合物或形成多孔分子框架的需要。酒精检测。