Uticaj gustine struje na morfologiju elektrohemijski dobijenog bakarnog praha

Abstract

U radu je ispitivan uticaj gustine struje na morfologiju elektrohemijski dobijenog bakarnog praha. Vršeno elektrohemijsko taloženje bakarnog praha iz sulfatnih elektrolita. Korišćeni su elektroliti sa tri koncentracije Cu2+ ( 7 g/dm3, 18 g/dm3 i 33 g/dm3 i svaka u kombinaciji sa tri koncentracije H2SO4 (100 g/dm3, 150 g/dm3 i 200 g/dm3), tako da je bakarni prah taložen iz devet elektrolita. Kao katoda je korišćena bakarna žica površine 1cm2, a bakarna anoda je bila priljubljena uz zid elektrohemijske laboratorijske ćelije zapremine 500cm³. Eksperimenti su rađeni na sobnoj temperaturi, a cirkulacija elektrolita vršena je pomoću magnetne mešalice. Bakarni prah taložen je galvanostatski pri gustinama struje od: j=1500A/m2, j=2000A/m2 i j=2500A/m2. Proizvedeni bakarni prah sa katode otresan je svakih tri minuta. Sve osobine praha zavise od oblika i dimenzije čestice (morfologije), od kojih je prah sačinjen i međusobno su povezane. Ispitivanje morfologije i veličine čestice vršeno je pomoću skenirajuće elektronske mikroskopije (SEM). Analizom dobijenih mikrofotografija utvrđeno je da se sa povećanjem gustine stuje morfologija čestica bakarnog praha menja od kompaktnih, masivnih dendrita i masivnih čestica, do razgranatih, 3D dendrita koji imaju strukturu kao zrna kukuruza. Sa povećanjem gustine struje dobijaju se sitnija zrna bakarnog praha koja su pravilno raspoređena.

The paper investigates the effect of current density on the morphology of copper powder obtained electrochemically. Copper powder from sulphate electrolytes was deposited electrochemically. The electrolytes used had three different concentrations of Cu2+ ( 7 g/dm3, 18 g/dm3 and 33 g/dm3) each combined with three concentations of H2SO4 (100 g/dm3, 150 g/dm3 and 200 g/dm3), so that copper powder was deposited from nine electrolytes. The cathode was a copper wire with the surface of 1cm2, whereas the copper anode was attached to the wall of the electrochemical laboratory cell with the volume of 500cm³. The experiments were performed at room temperature and the circulation of electrolytes was conducted using a magnetic stirrer. Copper powder was deposited galvanostatically at the following current densities: j=1500A/m2, j=2000A/m2 and j=2500A/m2. The copper powder produced was shaken off from the cathode every three minutes. All the properties of the powder depend on the shape and size of the particles (morphology) which constitute the powder and they are in correlation. Investigation of the morphology of particles was performed using scanning electron microscopy (SEM). The analysis of the obtained microphotographs shows that the increase of current density changes the morphology of copper powder particles from compact, massive dendrites and massive particles to branching 3D dendrites with the straucture of corn grains. The increase in current density results in smaller particles of copper powder which are evenly distributed.