PENGARUH VARIASI pH TERHADAP PENGUKURAN ASAM OKSALAT DENGAN ELEKTRODA GRAPHENE OXIDE TERMODIFIKASI NANOBENTONIT SECARA SIKLIK VOLTAMETRI THE EFFECT OF VARIOUS pH VALUES ON MEASUREMENT OXALIC ACID USING NANOBENTONITE MODIFIED GRAPHENE OXIDE ELECTRODE BY CY

Abstract

Telah dipelajari pengaruh pH pada pengukuran asam oksalat menggunakan elektroda Graphene oxide termodifikasi nanobentonit dengan metode siklik voltametri.Graphene oxide dan nanobentonitmasing-masing telah berhasil disintesis metode Improved Hummer dan Sonochemical. Elektroda dibuat dari campuran Graphene oxide:nanobentonit:parafin dengan perbandingan 3:2:5; 3:3:4; 3:4:3; 3:5:2. Variasi pH yang dipelajari yaitu 3,5; 4; 4,5; 5; dan 5,5. Kedua material tersebut di karakterisasi dengan FTIR dan PSA. Spektrum FTIR Graphene oxide membuktikan bahwa Graphene oxide telah berhasil disintesis dengan memunculkan gugus –OH pada bilangan gelombang3445cm-1., tekukan C=C pada bilangan gelombang1622cm-1, regangan gugus C-O pada bilangan gelombang 1225cm-1 dan regangan gugus epoksi C-O-C pada bilangan gelombang 1042cm-1. Spektrum FTIR nanobentonit menunjukkan serapan kuat pada bilangan gelombang 1028cm-1 menunjukkan regangan gugus Si-O-Si, pada bilangan gelombang 793 cm-1 menunjukkan regangan gugus Al-O-Si. Sementara data PSA menunjukan bahwa distribusi partikel graphene oxide sebanyak 5% berukuran 0,61μm. Data PSA menunjukkan bahwa distribusi partikel nanobentonit sebanyak 5 % berukuran 1.09μm. Hasil penentuan elektroda komposisi terbaik yaitu pada perbandingan komposisi 3:5:2 dengan arus puncak anodik sebesar 3,29x10-3 A. Pengukuran asam oksalat terbaik pada kondisi pH larutan 4,5 dengan arus puncak anodik sebesar 3,76x10-3 A.Kata kunci : voltametri siklik, elektroda Graphene oxide termodifikasi nanobentonit, asam oksalat The effect of pH on the measurement of oxalic acid using nanobentonite modified Graphene oxide electrodes with the cyclic voltammetry method. Graphene oxide and nanobentonite have been successfully synthesized by the Improved Hummer and Sonochemical methods. Electrodes are made from a mixture of Graphene oxide: nanobentonite: paraffin in a ratio of 3:2:5; 3:3:4; 3:4:3; 3:5:2. The pH variations studied were 3.5; 4; 4,5; 5; and 5.5. Both materials were characterized by FTIR and PSA. The FTIR spectrum of Graphene oxide proves that Graphene oxide has been successfully synthesized by raising the -OH group at wave number 3445cm-1. bend C=C at wave number 1622cm-1, the strain of C-O group at wave number 1225cm-1, and strain of epoxy group C-O-C at wave number 1042cm-1. The nanobentonite FTIR spectrum shows strong absorption at wave number 1028cm-1 indicating strain of the Si-O-Si group, at wave number 793 cm-1 indicating the strain of the Al-O-Si group. While the PSA data show that the distribution of graphene oxide particles as much as 5% measuring 0.61μm. PSA data show that the distribution of 5% nanobentonite particles is 1.09μm. The results of the determination of the best composition electrode are at a ratio of 3:5:2 with an anodic peak current of 3.29x10-3 A. The best measurement of oxalic acid at the pH of the solution 4.5 with an anodic peak current of 3.76x10-3 A.Key words: cyvlic voltammetry, nanobentonite modified Graphene oxide electrode, oxalic acid