A low-temperature-operating and highly moisture-resistant sea urchin-shaped CuO microsphere sensor for n-pentanol...

In this work, sea urchin-shaped CuO hierarchical microspheres assembled from two-dimensional nanosheets were synthesized via a facile one-step hydrothermal route for n-pentanol detection. Structural characterization studies confirmed the pure phase and porous hierarchical architecture of the as-obtained material, which possesses abundant active sites and efficient gas diffusion pathways. Gas sensing tests showed that the sensor based on sea urchin-like CuO microspheres presents a low optimal operating temperature of 175 °C, much lower than those of most previously reported n-pentanol sensors. At 175 °C, the sensor delivered a high response value of 9.2 toward 100 ppm n-pentanol, along with fast response/recovery times of 45 s and 23 s, respectively. Moreover, it maintained a stable sensing performance even under high relative humidity (90% RH), overcoming the poor humidity tolerance of conventional semiconductor gas sensors. Combined with material structure and surface chemical analysis, the enhanced sensing performance is attributed to the unique hierarchical structure and abundance of adsorbed oxygen species on the CuO surface. With the merits of low power consumption, fast response dynamics and superior environmental adaptability, the developed CuO sensor is promising for practical n-pentanol monitoring in complex atmospheric and industrial environments.