Glucose-Assisted Synthesis of Porous, Urchin-like Co 3 O 4 Hierarchical Structures for Low-Concentration Hydrogen Sensing Materials.

The Co 3 O 4 is a typical p-type metal oxide semiconductor (MOS) that attracted great attention for hydrogen detection. In this work, porous, urchin-like Co 3 O 4 was synthesized using a hydrothermal method with the assistance of glucose and a subsequent calcination process. Urchin-like Co 3 O 4 has a large specific surface area of 81.4 m 2 /g. The response value of urchin-like Co 3 O 4 to 200 ppm hydrogen at 200 °C is 36.5 (R g /R a ), while the low-detection limit is as low as 100 ppb. The obtained Co 3 O 4 also exhibited good reproducibility, long-term stability, and selectivity towards various gases (e.g., ammonia, hydrogen, carbon monoxide, and methane). Porous, urchin-like Co 3 O 4 is expected to become a potential candidate for low-concentration hydrogen-sensing materials with the above advantages.