PENGARUH VARIASI TEGANGAN ELEKTRODA TERHADAP SPEKTRUM ABSORBANSI OPTIK GRAPHENE OXIDE (GO) DARI BAHAN PENSIL 2B YANG DISINTESIS MENGGUNAKAN METODE ELEKTROLISIS THE IMPACT OF ELECTRODE VOLTAGE VARIATION TOWARDS OPTICAL ABSORBANCE SPECTRUM OF GRAPHENE OXIDE (GO) FROM PENCIL 2B MATERIAL WHICH IS SYNTHESIZED USING ELECTROLYSIS METHOD

Abstract

Abstrak
Penelitian ini bertujuan untuk mengetahui proses sintesis graphene oxide menggunakan metode elektrolisis dengan penambahan kumparan solenoida dan memvariasi tegangan elektroda serta massa serbuk graphite oxide, mengetahui pengaruh tegangan elektroda terhadap nilai absorbansi absolut dari graphene oxide yang dihasilkan, dan mengetahui pengaruh massa serbuk graphite oxide terhadap spektrum absorbansi spektrofotometer UV-Vis.
Penelitian ini dimulai dengan membuat larutan elektrolit yaitu H2SO4 0,5 M dan KOH 5,35 M. Selanjutnya proses elektrolisis dan penambahan kumparan solenoida dengan variasi tegangan bias pada elektroda sebesar 12 V, 15 V dan 18 V. Endapan graphite oxide yang dihasilkan di filtrasi, kemudian dilakukan pembersihan menggunakan aquades sampai pH nya netral dan ion sulfat sudah tidak ada pada endapan graphite oxide. Endapan hasil filtasi dikeringkan menggunakan oven selama 4 jam pada suhu 100 0C hingga menghasilkan serbuk graphite oxide. Serbuk graphite oxide dilarutkan dalam DMF dengan konsentrasi 0,1 mg/ml; 0,2 mg/ml; dan 0,3 mg/ml kemudian dilakukan ultrasonikasi selama 1 jam untuk menghasilkan graphene oxide. Proses pemisahan antara material yang berukuran besar dan kecil menggunakan centrifuge dengan kecepatan 500 rpm selama 10 menit. Proses karakterisasi material graphene oxide dilakukan dengan pengujian spektrofotometer UV-Vis.
Hasil penelitian menunjukkan bahwa variasi tegangan elektroda 12 V, 15 V, dan 18 V menghasilkan graphene oxide yang diindikasikan dengan adanya puncak absorbansi pada panjang gelombang 230 nm dan 250 nm dengan nilai absorbansi absolut sekitar 0,004 – 0,035. Pada variasi tegangan elektroda, semakin tinggi tegangan elektroda maka semakin tinggi nilai absorbansi absolutnya. Sedangkan pada variasi massa serbuk graphite oxide, semakin tinggi massa serbuk graphite oxide maka puncak absorbansi pada panjang gelombang tertentu semakin tinggi.
Kata Kunci : graphene, graphene oxide, elektrolisis, tegangan bias pada elektroda,
Abstract
This study aims 1) to determine the synthesis process of graphene oxide using electrolysis method with the addition of solenoid coil, 2) to vary the voltage of the electrode as well as the mass of graphite oxide powder, 3) to know the impact of electrode voltage toward the absolute absorbance value of graphene oxide produced, and 4) to determine the impact of mass of graphite oxide powder toward the absorbance spectrum of UV-Vis spectrophotometer.
The study began by making the electrolyte solution that is H2SO4 0,5 M and KOH 0,35 M. Furthermore, the electrolysis process and the addition of a solenoid coil were done with the bias voltage variation towards the electrodes at 12 V, 15 V, and 18 V. The sediment of graphite oxide produced was
2 | Jurnal Fisika Edisi Juli 2016
filtered and the cleaning process was done by using aquadest until reaching the neutral pH and there is no sulphate ion in the sediment of graphite oxide. The sediment of filtration results is dried using the oven for 4 hours at the temperature of 100 0C to produce graphite oxide powder. Graphite oxide powder was dissolved in DMF at the concentration of 0.1 mg/ml; 0.2 mg/ml; and 0.3 mg/ml and then the ultrasonication was done for 1 hour to produce graphene oxide. The separation process between the big-sized and the small-sized materials were done by using a centrifuge at the speed of 500 rpm for 10 minutes. The characterization process of graphene oxide material is done by using UV-Vis spectrophotometer.
The results showed that the variation of electrode voltage 12 V, 15 V, and 18 V produce graphene oxide which is indicated by the peak of absorbance at a wavelength of 230 nm and 250 nm with absolute absorbance value of about 0.004 to 0.035. On the electrode voltage variations, it is shown that the higher the electrode voltage, the higher the absolute absorbance values. While on the mass variation of graphite oxide powder, it is shown that the higher the mass of graphite powder oxide, the higher the absorbance peak at a specific wavelength. Keywords: graphene, graphene oxide, electrolysis, the bias voltage to the electrodes,