Sintesis Ni-Zn LHS (Layered Hydroxide Salts) Terimobilisasi Asam Sitrat Sebagai Adsorben [AuCl4]-

YULIZAH HANIFAH, Prof. Sri Juari Santosa, M.Eng., Ph.D;Prof. Dr. Bambang Rusdiarso, DEA

2020 | Tesis | MAGISTER KIMIA

Synthesis of citric acid immobilized Ni-Zn LHS and the quality assay as adsorbent of [AuCl4]- have been carried out. Ni-Zn LHS was synthesized by mixing Ni(NO3)2 with Zn(NO3)2 (2:1 molar rasio) then dropped with 32 mL of NaOH (0,75 M) using coprecipitation method for 60 minute. 32 mL NaOH solution has been selected which is based on crystallinity and purity of the produced Ni-Zn LHS. The synthesis result was carried out for immobilized with citric acid on optimum concentration and pH which was 200 mg L-1 and pH 7. To prove the success of synthesis before and after immobilization were comfirmed by FTIR spectrophotometer, XRD and SEM. Based on the result, Ni-Zn-LHS-AS were obtained as green solid. The FTIR spectra of Ni-Zn-LHS-AS showed the presence of characteristic vibration peaks at 1481 cm-1 which is C-H from citric acid . Performance assay of Ni-Zn-LHS-AS as adsorbent for [AuCl4]- such as pH optimal, contact time, adsorption kinetic and isoterm have been examined. The result showed that pH 3 was the optimum acidity for the adsorption of [AuCl4]-. [AuCl4]- adsorption was proved onto Ni-Zn-LHS-AS followed Ho pseudo second order kinetics with adsorption rate constant was 1,75 x 10-3 g. mg-1 minute-1. Adsorption [AuCl4]- of Ni-Zn-LHS-AS was followed the Freundlich isoterm model with adsorption capacity was 1,37 mg g-1. Based on the result obtained, it is known that Ni-Zn-LHS-AS has good performance for adsorption of [AuCl4]-.

Synthesis of citric acid immobilized Ni-Zn LHS and the quality assay as adsorbent of [AuCl4]- have been carried out. Ni-Zn LHS was synthesized by mixing Ni(NO3)2 with Zn(NO3)2 (2:1 molar rasio) then dropped with 32 mL of NaOH (0,75 M) using coprecipitation method for 60 minute. 32 mL NaOH solution has been selected which is based on crystallinity and purity of the produced Ni-Zn LHS. The synthesis result was carried out for immobilized with citric acid on optimum concentration and pH which was 200 mg L-1 and pH 7. To prove the success of synthesis before and after immobilization were comfirmed by FTIR spectrophotometer, XRD and SEM. Based on the result, Ni-Zn-LHS-AS were obtained as green solid. The FTIR spectra of Ni-Zn-LHS-AS showed the presence of characteristic vibration peaks at 1481 cm-1 which is C-H from citric acid . Performance assay of Ni-Zn-LHS-AS as adsorbent for [AuCl4]- such as pH optimal, contact time, adsorption kinetic and isoterm have been examined. The result showed that pH 3 was the optimum acidity for the adsorption of [AuCl4]-. [AuCl4]- adsorption was proved onto Ni-Zn-LHS-AS followed Ho pseudo second order kinetics with adsorption rate constant was 1,75 x 10-3 g. mg-1 minute-1. Adsorption [AuCl4]- of Ni-Zn-LHS-AS was followed the Freundlich isoterm model with adsorption capacity was 1,37 mg g-1. Based on the result obtained, it is known that Ni-Zn-LHS-AS has good performance for adsorption of [AuCl4]-.

Kata Kunci : Ni-Zn LHS, immobilization, citric acid, adsorption, [AuCl4]-