Electrocrystallization of Quinhydrone

Quinhydrone crystals were deposited at 2.0 V vs. Ag onto SnO2-coated glass substrates from aqueous solutions of hydroquinone in the presence of NaCl, HCl, or NaOH. The crystals were observed with backscattered image SEM, and characterized with X-ray diffraction and IR spectroscopy. In situ visible absorption spectra were measured and a mechanism of deposition is discussed.