One-pot solvothermal synthesis of hierarchical Co-doped NiO microspheres with enhanced hydrogen sulfide sensing performances
Wenjing Du,
Jinbo Zhao,
Fenglong Wang,
Huan Yang,
Ling Chen,
Xingyu Yao,
Lili Wu,
Jiurong Liu
Affiliations
Wenjing Du
College of Materials Engineering, Henan Key Laboratory of Electronic Ceramics Materials and Application, Henan International Joint Laboratory of Rare Earth Composite Materials, Henan University of Engineering, Zhengzhou 451191, China; Corresponding authors.
Jinbo Zhao
School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250100, China; Corresponding authors.
Fenglong Wang
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Huan Yang
Department of Chemical Engineering and Safety, Binzhou University, Binzhou 256600, China
Ling Chen
College of Materials Engineering, Henan Key Laboratory of Electronic Ceramics Materials and Application, Henan International Joint Laboratory of Rare Earth Composite Materials, Henan University of Engineering, Zhengzhou 451191, China
Xingyu Yao
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Lili Wu
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of School of Materials Science and Engineering, Shandong University, Jinan 250061, China; Corresponding authors.
Jiurong Liu
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of School of Materials Science and Engineering, Shandong University, Jinan 250061, China; Corresponding authors.
In this study we report, for the first time, the synthesis of Co-doped NiO microspheres assembled by two-dimension nanosheets using a facile solvothermal method. The H2S gas-sensing performance of the as-prepared samples was systematically investigated. The result demonstrates that the Co–NiO sensor with Co/Ni molar ratio of 1% (1% Co–NiO) exhibits high response (12.9) and rapid response speed (110 s) to 20×10−6 H2S at 200 °C in comparison with the pure NiO sensor. Moreover, excellent selectivity, repeatability, and stability were achieved. The sensing mechanism illustrates that the superior gas-sensing properties can be attributed to two factors. (1) The hierarchical microspherical construction with an ultrahigh specific surface area of 163.1 m2 g−1 provides adequate active sites for H2S gas adsorption, porous structures, and an interlayer gap that accelerates the diffusion of H2S gas, resulting in improved sensitivity and response speed of the sensor. (2) Co-doping results in a decrease in the particle sizes (ca. 4 nm) and increase in the number of adsorbed ionized oxygen species, which improves sensitivity and selectivity. Therefore, this study provides a facile approach for the synthesis of hierarchical Co–NiO microspheres with enhanced H2S gas-sensing performance.
