Cu-doped SnO/rGO nanocomposites for ultrasensitive HS detection at low temperature.

Hydrogen sulfide (HS) detection remains a significant concern and the sensitivity, selectivity, and detection limit must be balanced at low temperatures. Herein, we utilized a facile solvothermal method to prepare Cu-doped SnO/rGO nanocomposites that have emerged as promising candidate materials for HS sensors. Characterization of the Cu-SnO/rGO was carried out to determine its surface morphology, chemical composition, and crystal defects. The optimal sensor response for 10 ppm HS was ~1415.7 at 120 °C, which was over 320 times higher than that seen for pristine SnO CQDs (/ = 4.4) at 280 °C. Moreover, the sensor material exhibited excellent selectivity, a superior linear working range ( = 0.991, 1-150 ppm), a fast response time (31 s to 2 ppm), and ppb-level HS detection (/ = 1.26 to 50 ppb) at 120 °C. In addition, the sensor maintained a high performance even at extremely high humidity (90%) and showed outstanding long-term stability. These superb HS sensing properties were attributed to catalytic sensitization by the Cu dopant and a synergistic effect of the Cu-SnO and rGO, which offered abundant active sites for O and HS absorption and accelerated the transfer of electrons/holes.