Reduction of Chromium (VI) when Solar Selective Black Chromium is Deposited in the Presence of Organic Additive

B. N. Popov, Texas A & M University - College Station
Ralph E. White, University of South Carolina - Columbia
D. Slavkov, University Kiril and Metodij - Skopje,Yugoslavia
Z. Koneska, University Kiril and Metodij - Skopje,Yugoslavia

Abstract

Electrochemical dc methods were used to study the reduction of chromium (VI) in the presence of organic additives. It is shown that F, thiourea, and citric acid are essential to enable deposition of black chrome from concentrated chromic acid solutions. A new formulation of the plating bath is defined. The optimum operating conditions under which spectrally selective surface of black chrome is deposited have been determined.