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 - BAGAS PRAKOSO; Rita Prasetyowati (Prodi Fisika, Departemen Pendidikan Fisika, 2016)
AbstrakPenelitian ini bertujuan untuk mensintesis material graphene oxide menggunakan metodeelectrochemical exfoliation yang dikombinasikan dengan penambahan solenoida serta variasi lamaproses ultrasonikasi dan mengetahui pengaruh variasi lama ultrasonikasi terhadap hasil absorbansimaterial graphene oxide. Penelitian ini dimulai dengan mengelupas grafit pensil 2B menggunakanproses elektrolisis pada campuran larutan elektrolit kuat H2SO4 dan KOH. Hasil proses elektrolisislalu disaring dan dimurnikan menggunakan vacuum filtration pump sampai didapatkan serbukgraphite oxide yang memiliki pH netral. Serbuk hasil penetralan lalu dikeringkan dan ditimbangsebanyak 0,0003 gram, 0,0006 gram, dan 0,0009 gram. Serbuk itu selanjutnya dilarutkan dalam 4 mllarutan campuran DMF dan aquabides sehingga memiliki konsentrasi 0,1 mg/ml; 0,2 mg/ml; dan 0,3mg/ml. Tiga variasi konsentrasi ini selanjutnya di ultrasonikasi dengan waktu 30 menit, 60 menit, dan90 menit. Hasil proses ultrasonikasi selanjutnya diputar dalam centrifuge dengan kecepatan 500 rpm.Bagian atas dari larutan setelah proses centrifuge ini kemudian diambil untuk dilakukan karakterisasimenggunakan instrumen UV-Vis spektrofotometer. Hasil penelitian menunjukkan bahwa penggunaanmetode elektrolisis telah berhasil mensintesis material graphene oxide berbahan dasar pensil 2B yangditunjukkan dengan munculnya 2 puncak gelombang khas graphene oxide pada hasil uji UV-Visspektrofotometer. Selain itu, semakin lama waktu ultrasonikasi dilakukan, maka diperoleh nilaiabsorbansi material graphene oxide yang semakin tinggi juga, dimana hal itu mengindikasikankonsentrasi graphene oxide yang semakin besar.Kata Kunci: Graphene oxide, elektrolisis, ultrasonikasi, UV-Vis spektrofotometerAbstractThe aims of this research are 1) synthesizing graphene oxide material using theelectrochemical exfoliation method combined with additional solenoid coil and variation of ultrasonicationtime duration, 2) determining the impact of different ultra-sonication duration times towardthe absorbance results of graphene oxide material. Graphene is an allotropy material from carbonwhich has hexagonal structure similar to beehive and has superiority in some of its physicalproperties. This research was conducted first by exfoliating graphite of 2B pencil using electrolysis ina mixture solution of strong electrolyte of H2SO4 and KOH. The result of the electrolysis was2 | Jurnal Fisika Edisi Juli 2016screened and refined using vacuum filtration pump until graphite oxide powder is obtained which hasneutral pH. Then the powder obtained are dried and weighed for 0.0003 grams, 0.0006 grams, and0.0009 grams. The powder was then put into 4 mL of DMF and aquabides solutions thus producingthe concentrations of 0.1 mg/mL; 0.2 mg/mL; and 0.3 mg/mL. These variations of concentration arethen being ultra-sonicated for 30 minutes, 60 minutes, and 90 minutes. The results of the ultrasonicationare then rotated in a centrifuge with velocity of 500 rpm. The upper part of the solutionafter centrifuge process were then taken to be characterized using UV-Vis spectrophotometer. Theresults show that the electrolysis method has successfully synthesized graphene oxide material from2B pencil which was proven by the appearance of two distinct peaks of graphene oxide absorbancesin 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 greaterconcentration of graphene oxide.Keywords: graphene oxide, electrolysis method, UV-Vis spectrophotometer