Prasanti, Astarina AtikMukhtar, AkmalYanti, Pepi Helza2016-05-162016-05-162016-05-16wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/8381The synthesis of cobalt oxides by precipitation method have been done. (Co(NO3)2.6H2O and KOH was used as precursors in synthesis. Molar ratio of precursors 1:1 M. Temperature of calcination at 900oC was done to deteminate the crystalinity of cobalt oxides. The powder obtained were analyzed using XRD, size of particle of cobalt oxide was examined with Scherrer equation. The result revealed that temperature of calcination at 900 oC have highest intensity of Co3O4 minerals and size of particle was 40,47 nm. The optimum of time irradiation at 60 minute with mass of Co3O4 0,008 g the percentage is 20,06.enCobalt oxideprecipitationmetanil yellowdegradationstudent Paper Post Degree