SINTESIS DAN APLIKASI rGO DAN GOH SEBAGAI PEMODIFIKASI ELEKTRODA PADA ELEKTRODEGRADASI ZAT WARNA SAFRANINE O DAN CRYSTAL VIOLET

Titin Aryani, Prof. Drs. Mudasir, M.Eng., Ph.D; Prof. Drs. Roto, M. Eng., Ph.D

2025 | Disertasi | S3 Ilmu Kimia

Elektroda PbO? memiliki kinerja elektrodegradasi yang terbatas akibat rendahnya efisiensi dan stabilitas. Penelitian ini bertujuan mempelajari pengaruh modifikasi elektroda PbO? menggunakan reduced graphene oxide (rGO) dan grafena terfungsionalisasi hidroksil (GOH) terhadap kinerja elektrodegradasi zat warna safranine O dan crystal violet. Sintesis rGO dari arang aktif komersial dilakukan menggunakan metode hidrotermal. Sintesis GOH dari grafit dilakukan menggunakan kombinasi metode eksfoliasi elektrokimia, hidrotermal, dan ultrasonikasi. Modifikasi elektroda dilakukan menggunakan deposisi elektroforetik. rGO, GOH dan elektroda modifikasi dikarakterisasi menggunakan spektrofotometri ultra violet-visible (UV-Vis), spektrometer Fourier Transform Infra-red (FTIR), X-Ray diffractometer (XRD), spektrometri Raman, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX), dan Transmission Electron Microscopy (TEM). Aktivitas elektrotalitik diuji melalui voltametri siklik. Hasil karakterisasi menunjukkan bahwa rGO dan GOH terbentuk pada proses hidrotermal pada suhu 190 ºC selama 12 jam dengan komposisi (C 82,87%; O 17,13%) dan (C 67,08 %; O 32,92%). Modifikasi elektroda menghasilkan PbO₂/rGO dan PbO₂/GOH dengan aktivitas elektrokatalitik 72,73?n 73,31% lebih tinggi dari pada PbO₂. Modifikasi kedua elektroda dapat mengurangi pelarutan Pb 69,01?n 71,33%. Elektrodegradasi safranine O menggunakan PbO₂/rGO menghasilkan penurunan absorbansi, BOD, dan COD berturut-turut 99,00%, 96,77%, dan 97,00%, dengan rerata peningkatan efisiensi degradasi 38,21%. Elektrodegradasi crystal violet menggunakan PbO₂/GOH menghasilkan penurunan absorbansi, BOD, dan COD berturut-turut 99,36%, 94,08%, dan 95,79?ngan rerata peningkatan efisiensi degradasi 30,12%. Aplikasi kedua elektroda pada air limbah menghasilkan rerata peningkatan efisiensi degradasi 35,33?n 35,55%. Uji kinerja penggunaan ulang menunjukkan kedua elektroda dapat digunakan 10 kali. Hasil ini menunjukkan bahwa modifikasi dengan rGO dan GOH meningkatkan efisiensi degradasi dan stabilitas elektroda PbO?.

PbO? electrodes have limited electrodegradation performance due to low efficiency and stability. This study aims to investigate the effect of modifying PbO? electrodes using reduced graphene oxide (rGO) and hydroxyl-functionalized graphene (GOH) on the electrodegradation performance of safranine O and crystal violet dyes. rGO was synthesized from commercial activated charcoal using a hydrothermal method. GOH was synthesized from graphite using a combination of electrochemical exfoliation, hydrothermal, and ultrasonication methods. Electrode modification was performed using electrophoretic deposition. rGO, GOH, and modified electrodes were characterized using ultraviolet-visible (UV-Vis) spectrophotometry, Fourier Transform Infra-red (FTIR) spectrometry, X-Ray diffractometer (XRD), Raman spectrometry, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX), and Transmission Electron Microscopy (TEM). Electrolytic activity was tested through cyclic voltammetry. Characterization results showed that rGO and GOH were formed in a hydrothermal process at 190 ºC for 12 hours with compositions of (C 82.87%; O 17.13%) and (C 67.08%; O 32.92%). Modification of the electrode produced PbO₂/rGO and PbO₂/GOH with electrocatalytic activities 72.73% and 73.31% higher than PbO₂. Modification of both electrodes reduced Pb dissolution by 69.01% and 71.33%, respectively. Electrodegradation of safranine O using PbO₂/rGO resulted in a decrease in absorbance, BOD, and COD by 99.00%, 96.77%, and 97.00%, respectively, with an average increase in degradation efficiency of 38.21%. Electrodegradation of crystal violet using PbO₂/GOH resulted in a decrease in absorbance, BOD, and COD by 99.36%, 94.08%, and 95.79%, respectively, with an average increase in degradation efficiency of 30.12%. The application of both electrodes to wastewater resulted in an average increase in degradation efficiency of 35.33% and 35.55%. Reuse performance tests showed that both electrodes could be used 10 times. These results indicate that modification with rGO and GOH improves the degradation efficiency and stability of PbO? electrodes.

Kata Kunci : grafena, eksfoliasi elektrokimia, ultrasonikasi, hidrotermal, elektrodegradasi