Date of Publication
8-2025
Document Type
Bachelor's Thesis
Degree Name
Bachelor of Science in Chemistry
Subject Categories
Chemistry
College
College of Science
Department/Unit
Chemistry
Thesis Advisor
Jose Paolo O. Bantang
Defense Panel Chair
Lourdes P. Guidote
Defense Panel Member
Aldrin P. Bonto
Joan Candice V. Ondevilla
Abstract (English)
Supercapacitors are electrochemical devices capable of fast charge–discharge and high-power density, making them suitable for energy storage applications. This study aimed to fabricate nanocomposite electrodes using multi-walled carbon nanotubes (MWCNT) and κ-carrageenan-derived hydrochar for supercapacitor applications. Hydrochar was synthesized through hydrothermal carbonization and characterized by its morphology, elemental composition, surface functional groups, and iodine adsorption capacity. It was then blended with MWCNT at mass ratios of 100:0, 75:25, and 50:50 using a chitosan–citric acid binder to form composite electrodes. Electrochemical performance was evaluated in 0.1 M Na₂SO₄ using cyclic voltammetry at multiple scan rates and over 100 cycles. At 5 mV/s, the 50:50 electrode showed the highest areal specific capacitance of 479.7 mF/cm², followed by 416.7 mF/cm² (75:25) and 388.4 mF/cm² (100% MWCNT). However, all samples experienced significant capacitance loss at 100 mV/s, and only the MWCNT electrode retained its performance after 100 cycles (104.6%), while 75:25 and 50:50 retained just 17.7% and 4.5%, respectively. Near-rectangular voltammograms indicated electric double-layer behavior, while hydrochar-containing samples showed increased current and a broad oxidation peak near 0.6 V. These findings show that while hydrochar enhances initial capacitance through increased surface activity, it compromises long-term stability. The study demonstrates a sustainable route for electrode fabrication using green materials and methods.
Abstract Format
html
Abstract (Filipino)
Ang supercapacitor ay isang electrochemical na aparato na may kakayahang mag-imbak ng enerhiya. Ito ay may kakayahang mag-charge at mag-discharge nang mabilis at may mataas na power density. Layunin ng pag-aaral na ito na makagawa ng mga nanocomposite electrode gamit ang multi-walled carbon nanotubes (MWCNT) at hydrochar mula sa κ-carrageenan para makabuo ng supercapacitor. Ang hydrochar ay ginawa sa pamamagitan ng hydrothermal carbonization at sinuri batay sa morpolohiya, komposisyon ng elemento, mga functional groups, at kakayahang sumipsip ng yodo. Pagkatapos, ito ay hinalo sa MWCNT sa mga mass ratio na 100:0, 75:25, at 50:50 gamit ang chitosan–citric acid binder upang makabuo ng mga composite electrode. Sinuri ang electrochemical properties sa 0.1 M Na₂SO₄ gamit ang cyclic voltammetry sa iba’t ibang bilis ng pag-scan at sa loob ng 100 cycle. Sa 5 mV/s, ang 50:50 na electrode ay nagpakita ng pinakamataas na areal specific capacitance na 479.7 mF/cm², kasunod ang 416.7 mF/cm² (75:25) at 388.4 mF/cm² (100% MWCNT). Gayunman, lahat ng mga electrode ay nakaranas ng malaking pagbaba ng capacitance sa 100 mV/s, at tanging ang MWCNT electrode lamang ang nanatiling matatag matapos ang 100 cycle (104.6%), samantalang ang 75:25 at 50:50 ay nagpanatili lamang ng 17.7% at 4.5%, ayon sa pagkakasunod. Ang parihabang voltammogram ay nagpapakita ng electric double-layer behavior, samantalang ang mga sample na naglalaman ng hydrochar ay nagpakita ng mas mataas na current at isang malapad na oxidation peak sa humigit-kumulang 0.6 V. Ipinakikita ng mga natuklasan na habang pinapataas ng hydrochar ang paunang capacitance sa pamamagitan ng pagtaas ng surface activity, nakokompromiso naman ang pangmatagalang katatagan. Ipinapakita ng pag-aaral na ito ang isang paraan ng paggawa ng electrode gamit ang mga berdeng materyales at proseso.
(Note: This abstract was translated into Filipino with the help of ChatGPT, with additional edits by the authors and the advisor.)
Abstract Format
html
Language
English
Format
Electronic
Keywords
Supercapacitors; Carbon nanotubes
Recommended Citation
Perez, L. C., & Velez, L. T. (2025). Synthesis of MWCNT/hydrochar composite as electrodes for supercapacitor applications. Retrieved from https://animorepository.dlsu.edu.ph/etdb_chem/70
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Embargo Period
8-2026
