Highly sensitive H2O2 sensor based on Co3O4 hollow sphere prepared via a template-free method. (10th November 2015)

• Record Type: Journal Article
• Authors: Wang, Mei; Jiang, Xiaodan; Liu, Junjuan; Guo, Hailing; Liu, Chenguang
• Is Part Of: Electrochimica acta. Volume 182(2015)
• Page Start: 613
• Page End: 620
• Publication Date: 2015-11-10
• Subjects: Sensor -- Hydrogen peroxide detection -- hollow sphere -- cobalt oxide -- ZIF-67; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.08.116
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: High-activity nanoscale Co3 O4 hollow sphere has been developed using cobalt-containing imidazolate MOF framework ZIF-67 as precursor. The obtained cobalt oxide exhibited excellent electrocatalytic ability toward H2 O2, with a high sensitivity, a low detection limit, a broad linear sensing range, and a short response time. Highlights: Co-MOF ZIF-67 nanocrystals were synthesized by coordination modulation method. Co3 O4 hollow spheres were prepared by pyrolysis of ZIF-67. The obtained Co3 O4 own the high density of active metal sites. Co3 O4 modified electrode could effectively detect H2 O2 . The sensor showed high sensitivity, low detection limit, and broad linear range. Abstract: Hollow- sphere Co3 O4 nanoparticles were successfully synthesized by direct pyrolysis of cobalt-containing zeolitic imidazolate frameworks (ZIF-67) precursor. The transformation process from ZIF-67 to Co3 O4 hollow sphere was characterized by powder X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. It is found that the as-prepared Co3 O4 nanoparticles possesses uniform hollow spherical structure with many voids on the surface. It's worth noting that the high density of metal sites, the ordered arrangement of Co, as well as the uniform crystal size and regular morphology was inherited from ZIF-67, resulting in an excellent accessibility of Co. The resulting Co3 O4 hollow sphere was exploited as an electrocatalyst for sensitive H2 O2 detection in an alkaline medium. The Co3 O4 hollow sphere modified glassy carbon electrode exhibited a fast response time (within 3s), a high sensitivity of 120.55 μA/mM (959.79 μA∙mM −1 ∙cm −1 ), a broad linear range from 0.4 μM to 2.2 mM, a detection limit of 0.105 μM (S/N=3), and good stability and selectivity, suggesting its excellent performance towards H2 O2 detection.