ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

SILAR-synthesized CdO thin films for improved supercapacitive, photocatalytic and LPG-sensing performance

Mahima Ranjan Das and Partha Mitra

The University of Burdwan, Burdwan, India

E-mail: mitrapartha1@rediffmail.com

Abstract: In the presented work, the influence of cationic precursor molarity on supercapacitive, photocatalytic and LPG-sensing performance of CdO thin films synthesized by successive ionic layer adsorption and reaction method has been investigated. An attempt has been made to correlate the observed properties with structure and morphology of the deposited films. Structural characterization using XRD indicates an increase in crystallite size from ~ 12.3 to ~ 25.6 nm with increasing molarity of Cd²⁺ precursor solution from 0.1 M to 0.3 M, beyond which there is a reverse tendency. Band gap energy decreases from 2.22 to 2.04 eV with increasing molarity of Cd²⁺ precursor solution from 0.1 M to 0.3 M. For further increase of molarity to 0.4 M, the band gap energy increases to 2.08 eV. Thin film CdO electrode deposited from 0.3 M cadmium nitrate solution shows maximum specific capacitance of 228 Fg⁻¹ at a voltage scan rate of 2 mVs⁻¹ measured from cyclic voltammetry (CV) measurements. Charging–discharging measurements show maximum specific capacitance of 220 Fg⁻¹ at a current density of 1 Ag⁻¹. Capacitance retentivity of 96.5% after 5000 cycles was exhibited by the above said thin film electrode. Films deposited from 0.3 M Cd²⁺ content precursor solution also show improved photocatalytic activity as well as gas-sensing property in presence of LPG. The highest degradation of methyl orange dye of 76.2% under exposure to visible light of 200 W energy and maximum sensitivity of 78% in presence of 1000 ppm LPG at an operating temperature of 260 °C were observed.

Keywords: CdO thin film ; Supercapacitor ; Photocatalytic activity ; LPG sensitivity 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-019-00712-1

Chemical Papers 73 (7) 1605–1619 (2019)