29. How to prepare electrolyte solution for electrodeposition of ruthenium

Deposition of ruthenium is produced from the soleplate of an electrolyte with the following composition (g/l) and mode: The sulfamate ruthenium Ru (NH2S03)3 in terms of metal ....................4-7 Sulfamic acid NH2SO2OH ......45-55 Temperature, °C................ 70 The current density DK, A/dm2...........5-10 The current output t)to, %.............12-13 Insoluble anodes of platinum. The thickness of the layer of ruthenium in 30 min of electrolysis is 3-5 microns. The preparation of the electrolyte is made by fusing a powder of ruthenium with alkali and oxidant (on 1 g of the ruthenium 8 g of potassium hydroxide and 2.5 g of KNO3). The obtained Ru(OH)3 are dissolved in sulfamic acid. Dissolution of ruthenium for this electrolyte can be produced by using alternating current, as specified for the chloride electrolyte. In one of the electrolyte of sulfamic acid, ruthenium is introduced into the electrolyte in the form of nitrosochlorides in an amount up to 4 g/l in terms of metal*. S. Y. Griliches and D. S. Isakov [2] recommend the deposition of ruthenium from nitrocharger electrolyte with the Following composition (g/l) and mode of deposition: RuNOCl3 in terms of metal ruthenium 4-5 Sulfuric acid H2SO4 . Temperature, °C.............. 65-70 The current density DK, A/dm2 ......... 1,0—1,5 The current output %, % ...... ... U—15 From this electrolyte are obtained^bright and dense coatings with thickness up to 6 µm.

30.Discribe about electrolyte solution for electrodeposition of platinium.

Electrolytes suggested for platinum deposition, the most famous of phosphate and CIS-diaminoethane. For preparation of phosphate electrolyte metallic platinum was dissolved in Aqua Regia. The resulting chloride of platinum, crystallized in the form of a yellow crystals of H2PtCl6-6H20, neutralized with ammonia and the resulting ammonium chloroplatinate (NHJ2PtCl6 used for making the electrolyte [3]. For the deposition of coatings with thickness up to 200 µm I. E. Gurevich and V. I. Khalitova (Ural Polytechnic Institute) developed the ammonia electrolyte, in which the ammonium chloroplatinate goes into solution without additives ammonium phosphate. For him we recommend the following composition (g/l), and the mode of deposition: Chloroplatinate ammonium (NH4)2PtCIe..... 24 The electrolyte requires a preliminary study of the calculation to 20 A-h/l, without which benign coatings can not be obtained, and the current output is excessively low. In addition, it is necessary to apply the electrolyte with compressed air and to prevent the fall of chloroplatinate concentration below 5 g/l in terms of metal. For this purpose, should produce continuous adjustments of the electrolyte with ammonium chloroplatinate. The circulation rate of the electrolyte is small and should not be more than one volume of the bath for 30 hours. The saturation of the electrolyte with chloroplatinate ammonium is produced in a special collection for 4-5 hours at 60-65° C to increase the concentration up to 8-8,5 g/l in terms of metal. Platinum coating with a thickness of 200 µm to obtain a smooth, dense with little porosity, but have somewhat fragile, which is completely eliminated by annealing at 1300° C. There are also hydrochloric and sulfuric acid electrolytes with the use of soluble platinum anodes. Both electrolytes require the presence of chemically resistant metals, e.g. silver, as the underlayer during the deposition of platinum. - By dissolving metallic platinum to obtain various electrolytes are of great theoretical and practical interest is the dissolution of platinum in sulfuric acid under the action of alternating current from a common frequency of 50 Hz. This process has been studied for a number of metals Professor L. I. Cadavera. The concentration of sulfuric acid is taken subject to the availability of as bound and free acid. Heating of the electrolyte is not required. The electrodes serve as a platinum album. The current density of 15-25 A/dm2. The dissolution of platinum occurs with a low exit flow, equal to 0.10% to 0.15%. -The slowness of the process atoned for by his simplicity. Platinized titanium is produced to produce insoluble anodes. electrometallurgical and galvanic processes for metal deposition and also for the cathodic protection of Navy ships and different underwater constructions.

Началоформы

Конецформы