Claim Missing Document
Check
Articles

Found 2 Documents
Search

Sintesis Karbon Aktif dari Tongkol Jagung (Zea mays L.) dengan Metoda Dehidrasi sebagai Elektroda Superkapasitor Olly Norita Tetra; Raihan Hanif Aulia; Deswati Deswati
ALCHEMY Jurnal Penelitian Kimia Vol 21, No 2 (2025): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.21.2.96235.358-368

Abstract

Karbon aktif dari limbah tongkol jagung (Zea mays L.) telah disintesis dengan metoda dehidrasi untuk digunakan sebagai bahan elektroda superkapasitor. Bubuk tongkol jagung didehidrasi dengan H2SO4 1 M dan diaktivasi dengan KOH 5 M pada perbandingan massa karbon dan aktivator 1:2,5, dilanjutkan dengan karbonisasi pada 400 °C selama 1 jam. Hasil karakterisasi SEM menunjukkan terjadinya pembentukan pori pada permukaan karbon aktif dan hasil EDX memberikan persentase karbon 76,99%. Berdasarkan metode isoterm adsorpsi-desorpsi menunjukkan tipe isoterm IV dan histerisis tipe H3 yang menunjukkan struktur karbon aktif adalah mesopori, dengan luas permukaan spesifik 43,176 m2/g, volume pori 0,0855 cm3/g, dan distribusi pori rata-rata adalah 3,96 nm. Pengukuran sifat elektrokimia dari karbon aktif memberikan kemampuan untuk menyimpan energi dengan nilai kapasitansi spesifik sebesar 247,53 F/g dan rapat energi adalah 123,03 Wh/kg. Hasil EIS didapatkan kurva setengah lingkaran dari plot Nyquist yang menunjukkan adanya tahanan kecil untuk transfer muatan. Sintesis karbon aktif dengan metoda dehidrasi dan aktivasi menawarkan keuntungan seperti biaya rendah, proses preparasi sederhana, dan waktu sintesis singkat dengan kinerja elektrokimia yang tinggi untuk superkapasitor.Synthesis of Activated Carbon From Corncob (Zea mays L.) by Dehydration Method for Supercapacitor Electrode. Activated carbon from corn cob waste (Zea mays L.) has been synthesized using a dehydration method as a supercapacitor electrode material. Corn cob powder was dehydrated with 1 M H2SO4 and activated with 5 M KOH at a mass ratio of carbon and activator of 1:2.5, followed by carbonization at 400 °C for 1 hour. SEM characterization showed pore formation on the surface of activated carbon, and EDX results gave a carbon percentage of 76.99%. Based on the adsorption-desorption isotherm method, the isotherm type IV and hysteresis type H3 showed that the structure of activated carbon is mesoporous, with a specific surface area of 43.176 m2/g, a pore volume of 0.0855 cm3/g, and an average pore distribution of 3.96 nm. Measurement of the electrochemical properties of activated carbon provides the ability to store energy with a specific capacitance value of 247.53 F/g, and the energy density is 123.03 Wh/kg. EIS results obtained semicircular curves of Nyquist plots, indicating a slight resistance to charge transfer. The synthesis of activated carbon by the dehydration and activation method offers advantages such as low cost, simple preparation process, and short synthesis time with high electrochemical performance for supercapacitors.
Duck Eggshell Biosorbent for Indigo Carmine Removal: Kinetic, Isotherm, and Adsorption Mechanism Studies Adewirli Putra; Wiya E. Fitri; Deswati Deswati; Desy Kurniawati; Lia Anggresani; Corry Handayani; Aster Rahayu
Jurnal Akademika Kimia Vol. 15 No. 2 (2026)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2026.v15.i2.pp129-141

Abstract

Synthetic dye contamination from medical laboratory wastewater poses a growing environmental challenge, particularly from compounds such as indigo carmine, which are toxic, biologically recalcitrant, and detrimental to aquatic life. This research investigated duck eggshell as an eco-friendly, low-cost biosorbent for eliminating indigo carmine from medical laboratory effluents. The biosorbent was prepared by washing, oven-drying, grinding, and mild acid activation with 0.01 N HNO₃. Batch experiments were carried out by varying both the contact duration (15–60 min) and the initial dye concentration (10–50 mg/L), with residual concentrations determined using UV-Vis spectrophotometry. Adsorption kinetics were modeled using pseudo-first-order and pseudo-second-order equations, while equilibrium data were fitted to Langmuir and Freundlich isotherms. Peak adsorption capacity reached 8.20 mg/g within just 15 minutes of contact. The pseudo-second-order model gave the superior fit (R² = 0.9989), reflecting that surface-mediated interactions govern the process, though diffusion contributions cannot be excluded. Under optimal conditions, dye removal reached 67.80%, demonstrating efficient and rapid uptake. The Freundlich isotherm provided the best fit to the equilibrium data (R² = 0.9735), indicating multilayer uptake on an energetically heterogeneous surface. Overall, duck eggshell proved to be a practical, cost-effective, and sustainable material for removing dye pollutants from wastewater in the medical sector.