Electrolyte solutions in liquid ammonia—IX. Electrodeposition and electrodissolution of metals from their salts

An electrochemical technique for controlled dissolution of zirconium based components of light water reactors

“…27 This necessitates either using drastic conditions to overcome the "overpotential" due to the oxide layer. Gill and coworkers conducted electrodissolution of Zr in NH 4 BF 4 solution in liquid NH 3 at a temperature of À77 C. 28 Martin and coworkers summarized the various efforts at dissolution of zircaloy-2 alloys loaded with U fuel in various harsh media comprising of HNO 3 /uoride media, H 2 SO 4 /Fe 3+ / O 2 media and N 2 O 4 /TBP media. 29 More recent works have focused on dissolution of Zr-4 in high temperature (400 C), LiCl-KCl-ZrCl 4 molten salt matrices.…”

Electrochemical Synthesis of Ceramic Materials. 5. An Electrochemical Method Suitable for the Preparation of Nine Metal Nitrides

“…Application of current to the cell causes the solution to turn yellow, but it is red by the end of the experiment. In the study by Gill et al, anodic dissolution of W in NH 4 BF 4 /liquid NH 3 electrolyte resulted in an orange precipitate at the anode; however, they did not characterize this material . Soluble halides of W, such as WCl 6 , undergo ammonolysis in liquid NH 3 , so we expect that the reaction pathway that leads to the precursor is similar to that of Nb or V .…”

“…The pink color probably corresponds to [Ni(NH 3 ) 6 ]Br 2 , which is violet . The black deposits on the cathode are probably electrodeposited Ni. , …”

“…At the beginning of the electrolysis the solution turns brown, and then it becomes progressively darker. In another study, it was found that electrolysis of V in a NH 4 BF 4 /liquid NH 3 solution produced brown deposits on the anode, but they were not characterized , column 7) is very low.…”

“…At the beginning of the Ti electrolysis the solution turns yellow but then becomes green, possibly due to the presence of a blue e - NH 3 solution mixing with the otherwise yellow solution . In a study by Gill et al., anodic dissolution of Ti in a liquid NH 3 /NH 4 BF 4 electrolyte solution produced a pale yellow compound, but they did not report the structure of this material Ti salts undergo spontaneous ammonolysis in liquid NH 3 and the TiN precursor likely forms by a route similar to the NbN precursor .…”