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Efek Konsentrasi � � pada Sintesis Nanopartikel ��� dengan Metode Kopresipitasi
ABSTRAK
Telah dilakukan sintesis nanopartikel MgFe2O4 dengan variasi konsentrasi NH4OH
0,5, 0,9, 1,5, dan 2 M. Proses preparasi dimulai dari pencampuran serbuk Pasir Besi dan Magnesiumacetat Tetrahidrat (Mg(CH3COO)2.4H2O) dengan pelarut HCl dan
larutan pengendap NH4OH. Sampel kemudian dikeringkan dan dikarakterisasi,
meliputi analisa ukuran nanopartikel (FE-SEM), kerapatan serbuk (true density), ukuran dan struktur kristal (XRD), sifat magnetik (VSM) dan penyerapan limbah logam berat timbal (Pb2+) (AAS). Hasil FE-SEM menunjukan bahwa sampel MgFe2O4 telah mampu menghasilkan partikel berukuran nanometer. Dari hasil
analisa XRD dan True Density menunjukkan tidak adanya fasa pengotor dan hanya fasa tunggal MgFe2O4, dengan ukuran butir kristal cenderung menurun seiring
bertambahnya konsentrasi NH4OH dan densitas serbuk cenderung meningkat. Hasil
VSM menunjukkan koersivitas optimum terdapat pada saat konsentrasi NH4OH 0,9
M dengan nilai koersivitas 340,32 Oe, saturasi magnetik 52.95 emu/g, saturasi remanensi 13.54 emu/g. Hasil penyerapan AAS menunjukkan bahwa nanopartikel MgFe2O4 mampu menyerap limbah logam berat timbal (Pb2+) hingga 84,23%.
Kata kunci : Konsentrasi, Kopresipitasi, Nanopartikel, MgFe2O4
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The Effect of Concentration NH4OH on Synthesis Nanoparticles MgFe2O4 by
Coprecipitation Method
ABSTRACT
Nanoparticles MgFe2O4 has been synthesized by coprecipitation method with variation of NH4OH concentration : 0,5; 0,9; 1,5; and 2M. The process of preparation started from mixing of Iron Sand and Magneciumacetatetethrahidrate Mg(CH3COO)2.4H2O powder with HCl as solvent and NH4OH as setting solution. Sampels were dried and characterization include : analyze size of nanoparticles, (FE-SEM) True Density, size and crystal structure (XRD), magnetic properties (VSM) and absorption of heavy metal Pb (AAS). The result of FE-SEM showed that MgFe2O4 has been able to producenanometer sized particles. The results of XRD-pattern and true density were none of absoption and only single phase MgFe2O4 with crystal grain size tending to decrease with increasing concentration of NH4OH and true density tend to increase. The result of VSM showed that the optimum coercivity was achieved when of NH4OH concentration 0,9M with a value of 340.32 Oe,
magnetic saturation 52.95 emu/g, remanence saturation 13.54 emu/g. AAS
characterization showed that nanoparticles MgFe2O4 were able to absorb heavy metal of Timbal (Pb2+) up to 84,23%.
Keywords : Nanoparticles, NH4OH, Concentration, Coprecipitation
