Svojstva grafena pripremljenog eksfolijacijom persulfatom interkaliranog grafita u obradi voda

undergraduate thesis

• Title (english): Properties of graphene obtained by exfoliation of persulfate intercalated graphite for water treatment
• Author: Katarina Belošević
• Mentor: Marin Kovačić (mentor)
• Committee member: Marin Kovačić (predsjednik povjerenstva)
• Committee member: Hrvoje Kušić (član povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Izvanredna električna, optička i mehanička svojstva grafena čine grafen vrlo poželjnim materijalom ne samo u primjeni elektrokemijske pohrane energije, fleksibilne elektronike, medicini, već i u fotokatalizi za obradu otpadnih voda. Zadatak ovog rada bio je dobiti grafen ultrazvučnom eksfolijacijom ekspandiranog persulfatom interkaliranog grafita u vodi, te karakterizirati dobiveni produkt s ciljem primjene u fotokatalizi. Interkalacija je provedena u koncentriranoj sumpornoj kiselini s amonijevim persulfatom, čime je dobiveni interkalirani grafit (GIC). GIC je potom podvrgnut toplinskom šoku pri visokoj temperaturi čime je dobiven ekpandirani GIC (EGIC). Eksfolijacija je provedena u vodenom mediju s natrijevim lauril sulfatom kao surfaktantom, korištenim u svrhu stabilizacije dobivenih čestica grafena. Grafen je izdvojen iz suspenzije centrifugiranjem. Ispitana je mogućnost toplinske obrade izdvojenog grafena u svrhu pročišćavanja. Dobiveni uzorci karakterizirani su infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR) i termogravimetrijskom analizom (TGA) te pretražnom elektronskom mikroskopijom (SEM). Elektronska mikroskopija pokazala je da toplinski šok kojem je podvrgnut GIC rezultira značajnim raslojavanjem, čime je otvorena mogućnost dobivanja monosloja grafena ultrazvučnom eksfolijacijom. Termogravimetrijska analiza i FT-IR analize pokazale su da je dobiveni uzorak kemijski heterogen te vjerojatno onečišćen u znatnoj mjeri. U daljnjem istraživanju potrebno je unaprijediti proces ultrazvučne eksfolijacije i pročišćavanja kako bi se dobio grafen željenih svojstava.

Abstract (english)

Outstanding electrical, optical and mechanical properties of graphene make it a very desirable material, not only in the application of electrochemical energy storage, flexible electronics, medicine, but also in photocatalysis for wastewater treatment. The task of this work was to obtain graphene by ultrasonic exfoliation of expanded persulfate-intercalated graphite in water, and to characterize the obtained product with the intent to use the material in environmental photocatalysis. Intercalation was performed in concentrated sulfuric acid with ammonium persulfate to obtain intercalated graphite (GIC). GIC was then subjected to thermal shock at high temperature in order to obtain expanded GIC (EGIC). Exfoliation of the EGIC was further conducted in an aqueous medium with sodium lauryl sulfate as the surfactant, in order to stabilize the resulting graphene particles. Graphene was removed from the suspension by centrifugation. The possibility of heat treatment of the extracted graphene for the purpose of purification was investigated. The obtained samples were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Electron microscopy showed that the thermal shock to which GIC was subjected resulted in significant expansion of the individual layers, thus opening the possibility of obtaining a monolayer of graphene by ultrasonic exfoliation. Thermogravimetric analysis and FT-IR analysis showed that the obtained sample was chemically heterogeneous and probably contaminated up to a considerable extent. In further research it is necessary to improve the process of ultrasonic exfoliation and purification in order to obtain graphene of the desired properties.

• Keywords: grafen; interkalirani grafit; persulfat; eksfolijacija; ultrazvuk
• Keywords (english): graphene; intercalated graphite; persulfate; exfoliation; ultrasound
• Language: croatian
• URN:NBN: urn:nbn:hr:149:880048
• Project: Number: IP-2018-01-1982; Title: Nano-katalizatori aktivirani Sunčevim zračenjem u tehnologijama zaštite okoliša; Title: Nano-sized solar-active catalysts for environmental technologies; Acronym: NaSCEnT; Leader: Hrvoje Kušić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Environmental Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-05-02 11:53:51