Construction of hierarchical ZnO flower-like structure for boost H2S detection at low temperature

Novel flower-like ZnO nanomaterials were synthesized by a simple solvothermal method without using any template and surfactant combined with subsequent calcination. The resultant ZnO flowers displayed a hierar-chical structure with diameters of 1.4-1.6 mu m, consisting of overlapped nanorods grew radially from the center of the ZnO flowers. The gas sensors based on such ZnO flowers were highly sensitive to H2S gas in terms of a high response (157.3) and excellent selectivity towards 100 ppm H2S at the low operating temperature of 92 degrees C, accompanied with the detection limit of 0.05 ppm. The superior gas-sensing capabilities might benefit from the porous hierarchical architecture, which could facilitate the rapid adsorption of gas molecules and enhance the consequent charge transfer. Furthermore, the surface state of the ZnO flowers before and after exposure to H2S gas at 92 degrees C were investigated through the XPS technique and a possible H2S sensing mechanism over ZnO was proposed.

Automated summary

Novel flower-like ZnO nanomaterials were synthesized by a solvothermal method without using a template or surfactant. The resulting ZnO flowers had a hierarchical structure composed of nanorods that grew radially from the center. Gas sensors based on these ZnO flowers showed high sensitivity to H2S gas with a response of 157.3 and excellent selectivity at a low temperature of 92 degrees C. The porous hierarchical architecture of the ZnO flowers facilitated rapid gas adsorption and enhanced charge transfer, resulting in superior gas-sensing capabilities. The XPS technique was used to investigate the surface state of the ZnO flowers before and after exposure to H2S gas, and a possible sensing mechanism was proposed.