PENGARUH VARIASI LAMA WAKTU ULTRASONIKASI TERHADAP SPEKTRUM ABSORBANSI OPTIK GRAPHENE OXIDE (GO) DARI BAHAN PENSIL 2B YANG DISINTESIS MENGGUNAKAN METODE ELEKTROLISIS THE IMPACT OF DIFFERENT ULTRASONICATION DURATION TIME TOWARDS THE OPTICAL ABSORBANCE SPECTRUM OF GRAPHENE OXIDE FROM 2B PENCIL MATERIAL SYNTHESIZED USING ELECTROLYSIS METHOD

Abstract

Abstrak
Penelitian ini bertujuan untuk mensintesis material graphene oxide menggunakan metode
electrochemical exfoliation yang dikombinasikan dengan penambahan solenoida serta variasi lama
proses ultrasonikasi dan mengetahui pengaruh variasi lama ultrasonikasi terhadap hasil absorbansi
material graphene oxide. Penelitian ini dimulai dengan mengelupas grafit pensil 2B menggunakan
proses elektrolisis pada campuran larutan elektrolit kuat H2SO4 dan KOH. Hasil proses elektrolisis
lalu disaring dan dimurnikan menggunakan vacuum filtration pump sampai didapatkan serbuk
graphite oxide yang memiliki pH netral. Serbuk hasil penetralan lalu dikeringkan dan ditimbang
sebanyak 0,0003 gram, 0,0006 gram, dan 0,0009 gram. Serbuk itu selanjutnya dilarutkan dalam 4 ml
larutan campuran DMF dan aquabides sehingga memiliki konsentrasi 0,1 mg/ml; 0,2 mg/ml; dan 0,3
mg/ml. Tiga variasi konsentrasi ini selanjutnya di ultrasonikasi dengan waktu 30 menit, 60 menit, dan
90 menit. Hasil proses ultrasonikasi selanjutnya diputar dalam centrifuge dengan kecepatan 500 rpm.
Bagian atas dari larutan setelah proses centrifuge ini kemudian diambil untuk dilakukan karakterisasi
menggunakan instrumen UV-Vis spektrofotometer. Hasil penelitian menunjukkan bahwa penggunaan
metode elektrolisis telah berhasil mensintesis material graphene oxide berbahan dasar pensil 2B yang
ditunjukkan dengan munculnya 2 puncak gelombang khas graphene oxide pada hasil uji UV-Vis
spektrofotometer. Selain itu, semakin lama waktu ultrasonikasi dilakukan, maka diperoleh nilai
absorbansi material graphene oxide yang semakin tinggi juga, dimana hal itu mengindikasikan
konsentrasi graphene oxide yang semakin besar.
Kata Kunci: Graphene oxide, elektrolisis, ultrasonikasi, UV-Vis spektrofotometer

Abstract
The aims of this research are 1) synthesizing graphene oxide material using the
electrochemical exfoliation method combined with additional solenoid coil and variation of ultrasonication
time duration, 2) determining the impact of different ultra-sonication duration times toward
the absorbance results of graphene oxide material. Graphene is an allotropy material from carbon
which has hexagonal structure similar to beehive and has superiority in some of its physical
properties. This research was conducted first by exfoliating graphite of 2B pencil using electrolysis in
a mixture solution of strong electrolyte of H2SO4 and KOH. The result of the electrolysis was
2 | Jurnal Fisika Edisi Juli 2016
screened and refined using vacuum filtration pump until graphite oxide powder is obtained which has
neutral pH. Then the powder obtained are dried and weighed for 0.0003 grams, 0.0006 grams, and
0.0009 grams. The powder was then put into 4 mL of DMF and aquabides solutions thus producing
the concentrations of 0.1 mg/mL; 0.2 mg/mL; and 0.3 mg/mL. These variations of concentration are
then being ultra-sonicated for 30 minutes, 60 minutes, and 90 minutes. The results of the ultrasonication
are then rotated in a centrifuge with velocity of 500 rpm. The upper part of the solution
after centrifuge process were then taken to be characterized using UV-Vis spectrophotometer. The
results show that the electrolysis method has successfully synthesized graphene oxide material from
2B pencil which was proven by the appearance of two distinct peaks of graphene oxide absorbances
in the UV-Vis spectrophotometer test results. Furthermore, the longer the duration of the ultrasonication,
the greater the value of absorbance of graphene oxide which indicates the greater
concentration of graphene oxide.
Keywords: graphene oxide, electrolysis method, UV-Vis spectrophotometer