• P. N. Shelke
• Y. B. Khollam
• M. T. Sarode

Herein, a comparative study of NH3 gas sensing characteristics of DC electrochemically deposited Co3O4 films by using different Co-based precursors is reported. The Co3O4 films are deposited by using DC electrochemical deposition technique on thoroughly cleaned stainless steel (SS) and copper (CU) substrates. The Co3O4 films are deposited by using three water soluable Co-based precursors: (CH3COO)2Co, Co(NO3)¬2 and CoCl2 with CoSO4. All as-deposited Co-based films are annealed at 350 oC for 2 hr. All resultant cobalt oxide films are characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The NH3 gas sensing characteristcs of all resultant films are measured at room temperature by using static gas sensing system at different concentrations between 25 to 350 ppm of NH3 gas. The structural studies using XRD showed that resultant films contain pure Co3O4 phase with cubic spinel symmetry. The topographical studies using SEM indicated different particle morphology like kite, spherical and interlinked nanowires of Co3O4 films genearted by using the CoCl2 with CoSO4, Co(NO3)¬2 and (CH3COO)2Co precursors. The NH3 gas sensing properties of resultant films showed lowest response time for the films generated by using (CH3COO)2Co precursor. Further, recovery time is found to be lowest for the films generated by using (CH3COO)2Co precursor on copper substrate. However, sensing studies of resultant films showed that the sensitivity factor (S.F.) is maximum for the films obtained by using the CoCl2 with CoSO4 precursor on both SS and CU substrates. For all resultant films, the response time (2 - 5 min.) is found to be higher than the recovery time (25 - 45 sec.). The repeatability and reproducibility in gas sensing characteritsic is noted for all films. The highest NH¬3 sensing performance of CoCl2 precursor derived Co3O4 films is linked with morphological charateristics of corresponding films.

Co3O4 film; DC Electrochemical deposition; NH3 sensing; Sensitivity factor.

"Comparative NH3 gas sensing characteristics of DC electrochemically deposited Co3O4 films by using different Co-based precursors ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.27-31, MAY-2019, Available :http://www.jetir.org/papers/JETIRCM06009.pdf

"Comparative NH3 gas sensing characteristics of DC electrochemically deposited Co3O4 films by using different Co-based precursors ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp27-31, MAY-2019, Available at : http://www.jetir.org/papers/JETIRCM06009.pdf