Modulating pore size of three-dimensionally ordered macroporous WO₃ and their gas sensing properties to trace acetone

【作者】 王梦迪； 要红昌； 李中军；

【Author】 Meng-Di Wang;Hong-Chang Yao;Zhong-Jun Li;College of Chemistry and Molecular Engineering,Zhengzhou University;

【机构】 College of Chemistry and Molecular Engineering,Zhengzhou University；

【摘要】 Acetone in the human breath is a crucial biomarker for the clinical diagnosis of diabetes. Traditional methods of breath analysis have some technical limitations. In contrast, metal-oxide-based gas sensors have attracted considerable interest for their advantages in sensitivity, portability and real-time monitoring. Special attention has been paid to three-dimensionally ordered macroporous（3 DOM） metal oxides recently due to their macroporous structure with highly interconnected pores and mesoporous skeletons. Over the past years, various kinds of 3 DOM materials, including ZnO-CuO, Zn O-Fe₃ O₄ and Au/In₂ O₃, have been applied for acetone detection. However, several key challenges, especially sensitivity, selectivity and stability, should be further addressed before metal-oxide-based materials are capable of applying for acetone analysis. Herein, we synthesized a series of 3 DOM WO₃ with pore sizes from 205 to 730 nm by tuning the particle sizes of template PS spheres（250 ～ 880 nm）（Fig.1）. The sensors based on the 3 DOM WO₃ materials show high sensitivity to acetone down to 0.2 ppm, while the sensors show substantially lower response to other gases including ethanol, methanol, toluene, NH₃, NO and CO（Fig.2）. The results indicate that the optimized 3 DOM material possesses high sensitivity and good selectivity toward acetone vapor. Besides, the optimized sensor presented superior anti-interferential ability to various mixed-gas systems, and exhibited good long-term stability. More importantly, the gas sensing properties of 3 DOM WO₃ materials are proven to be closely related to its pore size and thus, the gas sensing properties can be modulated by tuning the particle size of PS templates. The gas sensing mechanism is also proposed.更多还原

【Abstract】 Acetone in the human breath is a crucial biomarker for the clinical diagnosis of diabetes. Traditional methods of breath analysis have some technical limitations. In contrast, metal-oxide-based gas sensors have attracted considerable interest for their advantages in sensitivity, portability and real-time monitoring. Special attention has been paid to three-dimensionally ordered macroporous（3 DOM） metal oxides recently due to their macroporous structure with highly interconnected pores and mesoporous skeletons. Over the past years, various kinds of 3 DOM materials, including ZnO-CuO, Zn O-Fe₃ O₄ and Au/In₂ O₃, have been applied for acetone detection. However, several key challenges, especially sensitivity, selectivity and stability, should be further addressed before metal-oxide-based materials are capable of applying for acetone analysis. Herein, we synthesized a series of 3 DOM WO₃ with pore sizes from 205 to 730 nm by tuning the particle sizes of template PS spheres（250 ～ 880 nm）（Fig.1）. The sensors based on the 3 DOM WO₃ materials show high sensitivity to acetone down to 0.2 ppm, while the sensors show substantially lower response to other gases including ethanol, methanol, toluene, NH₃, NO and CO（Fig.2）. The results indicate that the optimized 3 DOM material possesses high sensitivity and good selectivity toward acetone vapor. Besides, the optimized sensor presented superior anti-interferential ability to various mixed-gas systems, and exhibited good long-term stability. More importantly, the gas sensing properties of 3 DOM WO₃ materials are proven to be closely related to its pore size and thus, the gas sensing properties can be modulated by tuning the particle size of PS templates. The gas sensing mechanism is also proposed.更多还原