Synthesis of ZnO/ZnCo2O4 hollow tube clusters by a template method for high-sensitive H2S sensor

ZnO/ZnCo2O4 hollow tube clusters are fabricated by a one-step method using aster novi-belgii fluffs as bio-template, followed by calcination treatment at 500, 600 and 700 °C. The sensors fabricated with the ZnO/ZnCo2O4 hollow tube clusters display fine sensitivity to H2S. Herein, ZZCO-600 sensor presents high response value of 65.38–100 ppm H2S at 160 °C with the low detection limit of 30 ppb. Meanwhile, ZZCO-600 sensor also displays fast recover time (94 s for 10 ppm H2S), high selectivity, fitting linear relationship (R2 =0.997 for 1–100 ppm H2S and R2 =0.995 for 30–1000 ppb H2S), great repeatability and long-term stability. These superb performances of ZZCO-600 sensor are conducive to real-time and chronical monitoring in practical applications. Additionally, the XPS analysis is used to speculate the possible gas-sensing mechanism of ZZCO-600 towards H2S. Therefore, this work provides the structure design of ZnO/ZnCo2O4 hollow tube clusters for H2S detection and investigates their potential practical applications for high-sensitive gas sensors.