Electrodeposition and electrocatalytic characteristics of porous crystalline SnO2 thin film using butyl-rhodamine B as a structure-directing agent

Porous crystalline SnO2 thin films were electrodeposited from an oxygen-saturated acid aqueous solution of SnCl2 containing different amounts of butyl rhodamine B (BRhB) at 70 °C. BRhB can not only be dissolved in the acid deposition solution due to its amidocyanogen substitute, where HCl was added to suppress hydrolysis of SnCl2, but also be adsorbed on the surface of SnO2 through its carbonate substitute. Therefore, it was used as a structure-directing agent to control the growth of SnO2 crystals and then the crystalline structure and surface morphology of the deposited film. The electrodeposited thin films show porous morphology and rutile-type SnO2 crystalline structure due to the effects of BRhB on the growth, and these structural features can be adjusted by changing the added amount of BRhB. The SnO2 thin film electrodeposited with addition of BRhB exhibits electrocatalytic characteristic enhancement on oxidation of phenol due to its porous structure.