Sintesis dan Karakterisasi Material S-Doped Graphene Layer

Dini, Aisyah Putri (2026) Sintesis dan Karakterisasi Material S-Doped Graphene Layer. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Material S-doped graphene layer yang terdiri dari sulfur terdoping ke dalam kisi grafena berpotensi untuk dijadikan filler pada membran elektrolit DMFC karena dapat meningkatkan kestabilan mekanik, termal, dan mencegah methanol crossover. Penelitian ini bertujuan untuk menyintesis dan mengkarakterisasi material S-doped graphene layer sebagai filler berbahan dasar grafit melalui metode top-down dengan proses microwave-assisted synthesis yang dimulai dari interkalasi sulfur menggunakan H₂SO₄ diikuti dengan irradiasi microwave dengan variasi waktu 0, 5, 15, 30, dan 45 menit. Hasil sintesis menunjukkan bahwa terdapat perubahan fisik yang cukup menonjol dimana material S-doped graphene layer terlihat lebih mengkilap dan berwarna hitam keabu-abuan dibandingkan grafit yang berwarna hitam dan tidak terlalu mengkilap yang menandakan keberhasilan sintesis. S-doped graphene layer berwarna lebih terang serta semakin mengkilap seiring peningkatan variasi waktu microwave yang menunjukkan bahwa material akan cenderung mengalami aglomerasi dan ketidakstabilan struktur seiring peningkatan variasi waktu. Karakterisasi dilakukan menggunakan Fourier Transform Infrared Spectroscopy (FTIR) untuk mengkaji gugus fungsi yang menunjukkan keberadaan ikatan C–S dan menandakan keberhasilan doping sulfur tanpa terjadinya oksidasi berlebihan. Analisis X-Ray Diffraction (XRD) menghasilkan pergeseran puncak (002) dan penurunan ukuran kristalit seiring peningkatan variasi waktu microwave yang menunjukkan terjadinya proses eksfoliasi grafit menjadi few-layer graphene. Karakterisasi Raman menghasilkan pita G dominan, peningkatan pita D dan kemunculan pita D′, serta pita 2D berintensitas lebih rendah dari pita G seiring peningkatan variasi waktu microwave yang mengindikasikan kerangka grafena masih terjaga, bertambahnya cacat struktural dan distorsi kisi sp² akibat masuknya atom sulfur, dan dalam kondisi few-layer graphene. Hasil karakterisasi X-Ray Photoelectron Spectroscopy (XPS) menunjukkan dominasi ikatan C=C sp² yang menandakan keterjagaan struktur grafena disertai dengan keberadaan gugus fungsional C–O/C–S dan gugus oksigen polar (C–OH, C=O, dan O–C=O) pada permukaan material yang berperan dalam pembentukan jalur transpor proton dan peningkatan sifat penghalang terhadap difusi metanol. Berdasarkan keseluruhan hasil karakterisasi, S-doped graphene layer dengan variasi waktu microwave 15 dan 30 menit menunjukkan keseimbangan optimal antara keterjagaan struktur grafena dan keberadaan gugus fungsional aktif, sehingga berpotensi sebagai filler efektif untuk meningkatkan konduktivitas proton dan menurunkan permeabilitas metanol pada membran elektrolit DMFC.
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S-doped graphene layer material, consisting of sulfur doped into the graphene lattice, has potential to be used as a filler in DMFC electrolyte membranes because it can enhance mechanical and thermal stability while preventing methanol crossover. This study aims to synthesize and characterize S-doped graphene layer material as a graphite-based filler through a top-down method using microwave-assisted synthesis, beginning with sulfur intercalation using H₂SO₄ followed by microwave irradiation with varying durations of 0, 5, 15, 30, and 45 minutes. The synthesis results showed significant physical changes, where the S-doped graphene layer appeared shinier and grayish-black compared to graphite, which was black and less shiny, indicating successful synthesis. The S-doped graphene layer became lighter in color and increasingly shiny with longer microwave irradiation times, suggesting a tendency toward agglomeration and structural instability with prolonged exposure. Characterization using Fourier Transform Infrared Spectroscopy (FTIR) revealed functional groups indicating the presence of C–S bonds, confirming successful sulfur doping without excessive oxidation. X Ray Diffraction (XRD) analysis showed a shift in the (002) peak and a reduction in crystallite size with increasing microwave irradiation time, indicating the exfoliation of graphite into few layer graphene. Raman characterization roduced a dominant G band, an increase in the D band, the appearance of the D′ band, and a 2D band with lower intensity than the G band as microwave irradiation time increased, suggesting that the graphene framework remained intact, while structural defects and sp² lattice distortions increased due to sulfur incorporation, consistent with few-layer graphene. X-Ray Photoelectron Spectroscopy (XPS) results showed the dominance of C=C sp² bonds, indicating the preservation of the graphene structure, along with the presence of C–O/C–S functional groups and polar oxygen groups (C–OH, C=O, and O–C=O) on the material surface, which contribute to proton transport pathways and enhance barrier properties against methanol diffusion. Based on the overall characterization results, S doped graphene layers synthesized with microwave irradiation times of 15 and 30 minutes demonstrated an optimal balance between structural integrity and the presence of active functional groups, making them promising fillers to improve proton conductivity and reduce methanol permeability in DMFC electrolyte membranes.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	DMFC, Filler, Grafena, Karakterisasi, Sulfur, S-Doped Graphene Layer, Characterization, DMFC, Filler, Graphene, Sulphur, S-Doped Graphene Layer
Subjects:	Q Science > QD Chemistry > QD341.H9 Graphene Q Science > QD Chemistry > QD553 Electrochemistry. Electrolysis
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis
Depositing User:	Aisyah Putri Dini
Date Deposited:	04 Feb 2026 09:02
Last Modified:	04 Feb 2026 09:02
URI:	http://repository.its.ac.id/id/eprint/132135

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