Abstract The g-C3N4 decorated titanium dioxide (TiO2) porous nanospheres composites thin films were successfully synthesized via a spray pyrolysis technique. The structural, morphological and textural properties of the fabricated thin film sensors were analyzed through X-ray diffraction (XRD), electron microscopy (SEM and TEM), Raman and N2 adsorption-desorption analysis. The incorporation g-C3N4 in to TiO2 matrix was also confirmed through Energy dispersive spectra (EDS) and X-ray photoelectron microspore (XPS) analysis. Gas-sensing properties of the pure and g-C3N4/TiO2 hybrid thin film sensors were investigated towards H2S and CO2 gases with various ppm levels (0–1500). The results illustrates that 10 wt.% g-C3N4 decorated TiO2 composite film show outstanding sensing response (88%) and high stability (only loss 2.5% of its initial response value) towards CO2 gas at 1500 ppm (450 °C), which is comparatively high response towards H2S gas (67%) under same ppm level. The improved sensing response is due to the incorporated g-C3N4 could provide high conductivity, large surface area (108.5 m2/g) with porous nature (15.7 nm), which is consists of interconnection between g-C3N4 nanosheets and TiO2 spheres. The improved mechanism of the proposed sensor was also discussed in detail.

中文翻译：

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设计和制造 g-C3N4 纳米片装饰的 TiO2 混合传感器薄膜以提高对 CO2 气体的性能

摘要 采用喷雾热解技术成功合成了 g-C3N4 修饰的二氧化钛 (TiO2) 多孔纳米球复合薄膜。通过 X 射线衍射 (XRD)、电子显微镜 (SEM 和 TEM)、拉曼和 N2 吸附-解吸分析来分析制造的薄膜传感器的结构、形态和纹理特性。通过能量色散谱 (EDS) 和 X 射线光电子微孢子 (XPS) 分析也证实了 g-C3N4 掺入到 TiO2 基质中。研究了纯和 g-C3N4/TiO2 混合薄膜传感器的气敏特性，研究了各种 ppm 水平（0-1500）的 H2S 和 CO2 气体。结果表明，10 wt.% g-C3N4 装饰的 TiO2 复合膜表现出出色的传感响应（88%）和高稳定性（仅损失 2. 其初始响应值的 5%）对 1500 ppm (450 °C) 的 CO2 气体，这在相同 ppm 水平下对 H2S 气体（67%）的响应相对较高。改进的传感响应是由于掺入的 g-C3N4 可以提供高电导率、大表面积 (108.5 m2/g) 和多孔性质 (15.7 nm)，由 g-C3N4 纳米片和 TiO2 球体之间的互连组成。还详细讨论了所提出的传感器的改进机制。