Browsing by Author Tran, Thi Ngoc Hoa

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  • Authors: Tran, Thi Ngoc Hoa;  Advisor: Nguyen, Van Duy; Chu, Manh Hung; Nguyen, Van Hieu; Ho, Huu Hau; Nguyen, Duc Hoa;  Co-Author: - (2021)

    SnO2 nanowires (NWs) are used in gas sensors, but their response to highly toxic gas H2S is low. Thus, their performance toward the effective detection of low-level H2S in air should be improved for environmental-pollution control and monitoring. Herein, Ag2O nanoparticle decorated SnO2 NWs were prepared by a simple on-chip growth and subsequent dip-coating method. The amount of decorated Ag2O nanoparticles on the surface of SnO2 NWs was modified by changing the concentration of AgNO3 solution and/or dipping times. Gas-sensing measurements were conducted at various working temperatures (200–400 °C) toward different H2S concentrations ranging within 0.1–1 ppm. The selectivity of Ag2O-d...
  • Authors: Tran, Thi Ngoc Hoa;  Advisor: Dang, Thi Thanh Le; Nguyen, Van Toan; Chu, Manh Hung; Nguyen, Van Hieu; Nguyen, Duc Hoa;  Co-Author: - (2021)

    The enhancement of the H2S gas-sensing performance of SnO2 nanowires is vital for practical application. In this study, H2S gas sensors based on WO3-coated SnO2 nanowires were fabricated through a two-step process, namely, the chemical vapor deposition of SnO2 nanowires and then coating with WO3 by sputtering method. The morphology and crystal structures of the SnO2 nanowires coated with WO3 were investigated by field-emission scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The H2S gas-sensing properties of the fabricated sensors were tested at temperatures of 150–250 °C. The SnO2 nanowires coated with 5 nm WO3 showed the best ...