title: Chelating-Template-Assisted in Situ Encapsulation of Zinc Ferrite Inside Silica Mesopores for Enhanced Gas-Sensing Characteristics.
abstract: A facile in situ approach has been designed to synthesize zinc ferrite/mesoporous silica guest-host composites. Chelating surfactant, N-hexadecyl ethylenediamine triacetic acid, was employed as structure-directing agent to fabricate mesoporous silica skeleton and simultaneously as complexing agent to incorporate stoichiometric amounts of zinc and iron ions into silica cavities. On this basis, spinel zinc ferrite nanoparticles with grain sizes less than 3 nm were encapsulated in mesoporous channels after calcination. The silica mesostructure, meanwhile, displayed a successive transformation from hexagonal p6mm through bicontinuous cubic Ia3̅d to lamellar phase with increasing the dopant concentration in the initial template solution. In comparison with zinc ferrite nanopowder prepared without silica host, the composite with bicontinuous architecture exhibited higher sensitivity, lower detection limit, lower optimum working temperature, quicker response, and shorter recovery time in sensing performance toward hydrogen sulfide. The significant improvements are from the high surface-to-volume ratio of the guest oxides and the three-dimensional porous structure of the composite. We believe the encapsulation route presented here may pave the way for directly introducing complex metal oxide into mesoporous silica matrix with tailorable mesophases for applications in sensing or other fields.
authors: Chemistry Department & College of Life Science and Technology & Center of Instrumental Analysis, Hebei Normal University of Science and Technology , Qinhuangdao 066004, PR China.
authors: Kui
authors: K
authors: Niu
authors: Chemistry Department & College of Life Science and Technology & Center of Instrumental Analysis, Hebei Normal University of Science and Technology , Qinhuangdao 066004, PR China.
authors: Liman
authors: L
authors: Liang
authors: Chemistry Department & College of Life Science and Technology & Center of Instrumental Analysis, Hebei Normal University of Science and Technology , Qinhuangdao 066004, PR China.
authors: Fei
authors: F
authors: Peng
authors: Chemistry Department & College of Life Science and Technology & Center of Instrumental Analysis, Hebei Normal University of Science and Technology , Qinhuangdao 066004, PR China.
authors: Fan
authors: F
authors: Zhang
authors: The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, Jiangnan University , Wuxi 214122, PR China.
authors: Yao
authors: Y
authors: Gu
authors: Chemistry Department & College of Life Science and Technology & Center of Instrumental Analysis, Hebei Normal University of Science and Technology , Qinhuangdao 066004, PR China.
authors: Hongyan
authors: H
authors: Tian
keywords: chelating template; hydrogen sulfide sensor; mesophase; mesoporous composite; zinc ferrite