INTERKALASI ASAM GALAT PADA Mg/Al-HIDROTALSIT MELALUI METODE KOPRESIPITASI LANGSUNG DAN PENGGUNAANNYA UNTUK ADSORPSI-REDUKSI AuCl4 ??; INTERCALATION OF GALLIC ACID IN Mg/Al-HYDROTALCITE THROUGH DIRECT COPRECIPITATION METHOD AND ITS APPLICATION TO REDUCTIVE ADSORPTION AuCl4 ?
Yanti, Ika, Sri Juari Santosa
2015 | Disertasi | FMIPAIntercalation of gallic acid (GA) in Mg/Al-Hydrotalcite (Mg/Al-HT) and its application to reductive adsorption of AuCl4 ? have been conducted. Intercalation of GA on Mg/Al-HT has been performed by direct coprecipitation method of Mg(NO3)2, Al(NO3)2 and GA at various molar ratios and medium acidities. The intercalation products of GA in Mg/Al-HT-GA were characterized by spectrometer FTIR and diffractometer XRD.The effect of molar ratios and pH of synthesis, kinetic and isoterm adsorptions, and Au(III) reduction were also studied. The gold metal formed was confirmed by spectrometer FTIR, photomicroscope stereo and diffractometer XRD. Intercalation of GA in Mg/Al-HT with molar ratios of Mg2+:Al3+:GA (2:1:0.05); (2:1:0.1); (2:1:0.2); (2:1:0.3) and (2:1:0.5) was optimum at pH 10. The analysis using spectrometer FTIR and diffractometer XRD showed that GA has been intercalated in interlayer of Mg/Al-HT with the value of d (basal spacing d003) was observed to increase with the increasing of the consentration of GA. Intercalation of GA in Mg/Al-HT with molar ratios of Mg2+:Al3+:GA (2:1:0.5) was occurred at pH 7, 8, 9, 10 and 11. The result of characterization using spectrometer FTIR and diffractometer XRD showed that pH affected the value of basal spacing (d003) of Mg/Al-HT-GA, the amount and anion spesies of GA and consequently affected the adsorption of AuCl4 ?. The adsorption of AuCl4 ? by Mg/Al-HT-GA was optimum at pH 3 and followed pseudo-second order kinetic and Langmuir isoterm models with rate constant (k) and adsorption capacity were 3.798x10-4 g.mg-1.minute-1 and 625 mg.g-1, respectively. Characterization with photomicroscope and diffractometer XRD showed that Au(III) could be reduced to Au(0) with peaks of gold particle in the diffractogram were appeared at 2?=37.4?; 43.6?; 63.9? and 76.9? and lattice parameter (a) of 4.135 Å.
Kata Kunci : Intercalation; gallic acid; Mg/Al-Hydrotalcite; AuCl4 ?; adsorption; reduction.
