Synthesis of Citrate-Capped Gold Nanoparticles from Reduced [AuCl4]– on Ascorbic Acid-Immobilized Mg/Al Hydrotalcite

Agustina Sus Andreani (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia)
Suyanta Suyanta (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia)
Eko Sri Kunarti (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia)
Sri Juari Santosa (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia)

Indonesian Journal of Chemistry
Vol 18, No 3 (2018)

Reductive adsorption of [AuCl4]-– by using ascorbic acid immobilized on Mg/Al hydrotalcite (Mg/Al HT) and synthesis of gold nanoparticles (AuNPs) from the reduced gold using sodium citrate have been conducted. Mg/Al HT was synthesized by co-precipitation method at pH 10 with molar ratio of Mg(II) and Al(III) 2:1. Ascorbic acid (AA) was then immobilized on Mg/Al HT to form hybrid of AA and Mg/Al HT (Mg/Al HT-AA). Mg/Al HT-AA was used to reductively adsorb [AuCl4]– and the formed Au(0) was extracted by using sodium citrate to form citrate-capped AuNPs. The formation of AuNPs from 100 mg/L [AuCl4]– solution removed by 60 mg Mg/Al HT-AA was optimum at pH 5.0, by using 70 mM sodium citrate and 2 h sonication time. This optimum condition was successfully applied to synthesize AuNPs from [AuCl4]– as the leaching product of gold from PCB using aquaregia.