Photoelectrochemical determination of Pb2+ by combined electrochemical-chemical precipitations of PbI2 films

Abstract

• Combined method of chemical and electrochemical depositions films of PbI 2 . • Photoelectrochemical content definition of Pb 2+ by photocurrent magnitude of PbI 2 thin films. • Selective photoelectrochemical definition of Pb 2+ in acidic nitrate solutions. A simple and inexpensive method of selective photoelectrochemical determination of Pb 2+ content in acidic nitrate solutions has been developed, which can be used to control the lead content in wastes of the chemical industry and processing industry. For selective photoelectrochemical determination of lead concentration, studies of the effect of time and current of electrodeposition, oxide compounds of lead and conditions of conversion PbO 2 into PbI 2 on a glass/SnO 2 substrate were performed. The main objective of these studies was to determine the relationship between the photosensitivity of PbI 2 films and time and current of PbO 2 electrodeposition in solutions with different amounts of lead ions. From the analysis of interferometric studies of electrochemical growth PbO 2 films and PbI 2 quantum yield spectra of photocurrent, the optimal values of time and current of electrodeposition were established. Established of dependency quantum yield of photocurrent of lead concentration products in the form of PbI 2 thin films depends on the thickness of electrodeposited PbO 2 , which in turn depends directly on the concentration of Pb 2+ ions in the analyzed solution. It was found that sensitivity of method can reach 0.05 mg/L (Pb 2+ ).