Facile Growth and Promising Applications of Cobalt Oxide (Co3O4) Nanoparticles as Chemi-Sensor and Dielectric Material

Background: Co3O4 in nano-size has been found efficient in electronic and optoelectronic devices. P-type semiconductor behavior, typical spinel crystal structure, and dual optical band gap extend the practical application of Co3O4 nanoparticles. Objective: The main objective of the presented work is to exploit the Co3O4 nanoparticles as chemisensor and dielectric material. Method: Nanoparticles of Co3O4 was prepared by hydrothermal method. The structural and optical properties of as-grown nanoparticles were investigated by powder XRD, FE-SEM, EDS, FTIR, UVVIS- NIR spectrophotometer, and Raman spectrometer. Sensing, and dielectric properties were explored by measuring the response of current versus voltage (I-V), and capacitance versus frequency (C-f), respectively. Result: As-grown nanoparticles exhibited the distinguished properties, such as: well crystalline cubic structure of lattice parameter (a = 8.083 Å), comparable crystallite (~ 60 nm) and particle sizes (~ 65nm), dual optical energy band gaps (1.75 eV, 3.1 eV), the high value of sensitivity (31.48 µA mM- 1cm-2) and dielectric constant, low value of dielectric loss, and a good ac conductivity. Low value of dielectric loss indicates the purity and a good optical behavior of the material. A possible sensing mechanism has been explained, and a factual method of data evaluation has been authenticated. Conclusion: As-gown nanoparticles were found suitable for chemi-sensor and capacitor. Low particle size, p-type conductivity, dual energy band gap, well crystalline nature, the high value of dielectric constant, low value of dielectric loss, and good ac conductivity demonstrate the potential candidature of Co3O4 nanoparticles as efficient charge carriers in chemical sensors and capacitors. Keywords: Nanoparticles, synthesis, structural characterization, optical characterization, chemical sensor, dielectric properties.