Abstract In this study, the effects of reduced graphene oxide (rGO) loading on the gas-sensing characteristics of flame-made Bi2WO6 nanoparticles were systematically investigated. Bi2WO6 nanoparticles produced by flame spray pyrolysis (FSP) were loaded with rGO prepared based on Hummer's method with varying concentrations from 0 to 5 wt%. Characterized results by X-Ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, Raman spectroscopy, X-ray photoemission spectroscopy and nitrogen adsorption confirmed the dispersion of rGO sheets within 5–15 nm FSP-made orthorhombic Bi2WO6 nanoparticles. The gas-sensing data measured in dry air demonstrated that the optimal rGO loading level of 2 wt% provided substantial enhancements of H2S response and selectivity. Specifically, the 2 wt% rGO-loaded Bi2WO6 sensor exhibited the highest response of ~29 towards 10 ppm H2S with high selectivity against H2, CH4, NO, NO2, C7H8, CH2O, C8H10, C6H6, C3H6O, CH3OH, C2H5OH, C3H6O2, C3H6O3, C4H8O2, CH3COOH, C4H9COOH and HCOOH at an optimal working temperature of 350 °C. The roles of rGO on gas-sensing behaviors were explained on the basis of p-n heterojunctions between rGO and Bi2WO6. Therefore, the rGO-loaded Bi2WO6 sensor is an attractive candidate for H2S detection.

中文翻译：

---

减少氧化石墨烯负载量对火焰制备的 Bi2WO6 纳米粒子气敏特性的影响

摘要 在这项研究中，系统研究了还原氧化石墨烯 (rGO) 负载对火焰制造的 Bi2WO6 纳米粒子气敏特性的影响。通过火焰喷雾热解 (FSP) 生产的 Bi2WO6 纳米颗粒负载有基于 Hummer 方法制备的 rGO，浓度从 0 到 5 wt%。X 射线衍射、扫描和透射电子显微镜、能量色散光谱、拉曼光谱、X 射线光电发射光谱和氮吸附的表征结果证实了 rGO 片在 5-15 nm FSP 制造的正交 Bi2WO6 纳米粒子中的分散。在干燥空气中测量的气敏数据表明，2 wt% 的最佳 rGO 负载水平显着提高了 H2S 响应和选择性。具体来说，负载 2 wt% rGO 的 Bi2WO6 传感器对 10 ppm H2S 表现出 ~29 的最高响应，对 H2、CH4、NO、NO2、C7H8、CH2O、C8H10、C6H6、C3H6O、CH3OH、C2H5OH、C3H6O2、C3H6O3 具有高选择性C4H8O2、CH3COOH、C4H9COOH 和 HCOOH，最佳工作温度为 350 °C。基于 rGO 和 Bi2WO6 之间的 pn 异质结解释了 rGO 在气敏行为中的作用。因此，加载 rGO 的 Bi2WO6 传感器是 H2S 检测的有吸引力的候选者。