Mehanokemijska sinteza nanočestica ZnO dopiranog kadmijem

master's thesis

• Title (english): Mechanochemical synthesis of Cd-doped ZnO nanoparticles
• Author: Ivana Katarina Munda
• Mentor: Stanislav Kurajica (mentor)
• Committee member: Stanislav Kurajica (predsjednik povjerenstva)
• Committee member: Vilko Mandić (član povjerenstva)
• Committee member: Gordana Matijašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

Istraživano je koliki se udio kadmija može ugraditi u kristalnu rešetku cinkita mehanokemijskom sintezom. Kao prekursori su korišteni metalni kloridi i natrijev karbonat dok je natrijev klorid korišten kao razrjeđivač. Nakon mehanokemijske sinteze uzorci su termički obrađeni pri 600 °C u trajanju 2 sata kako bi se iz ZnCO3 dobio ZnO. Pripremljeni uzorci ispitani su rendgenskom difrakcijom praha (XRD), infracrvenom spektroskopijom s Fourierovom transformacijom tehnikom prigušene totalne refleksije (FTIR-ATR), UV-Vis difuznom refleksijskom spektroskopijom (DRS), elektronskim pretražnim mikroskopom (SEM) i energetski razlučujućom rendgenskom spektroskopijom (EDS). Fotokatalitička učinkovitost vrednovana je na temelju procesa razgradnje organske boje metilenskog plavila (MB), praćenog UV-VIS spektroskopijom. Rezultati su pokazali da je mehanokemijskom sintezom iz korištenih prekursora u rešetku cinkita moguće ugraditi do 2 % kadmija, te da se pri većim udjelima kadmija osim cinkita pojavljuju i druge faze poput kadmijeva oksida i kadmijeva karbonata. Dopiranjem cinkita kadmijem dovodi do pojave većih kristalita ZnO. Dopiranjem kadmijem ne postižu se veće promjene u morfologiji, energiji zabranjene zone niti fotokatalitičkoj aktivnosti ZnO.

Abstract (english)

The limit of zincite crystal lattice doping with cadmium in the course of mechanochemical synthesis has been investigated. Metal chlorides and sodium carbonate were used as precursors and sodium chloride as diluent. After mechanochemical synthesis samples were thermally treated at 600 °C for 2 h, in order to enable transformation of ZnCO3 to ZnO. The prepared samples were characterized by X-ray diffraction (XRD), Attenuated total reflectance Fourier-transformed infrared spectroscopy (FTIR-ATR), UV–Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Photocatalytic efficiency has been evaluated through methylene blue (MB) dye degradation process via UV-Vis spectroscopy. The results showed that limit of Zn replacement with Cd in ZnO crystal lattice via mechanochemical synthesis with precursors used is only 2 %. In a presence of larger share of Cd, cadmium oxide or carbonate phases appears. It was noted that doping with Cd impair ZnO nanocrystallinity. No significant differences of ZnO band-gap, morphology and photocatalytic activity with doping were observed.

• Keywords: cinkit; kadmij; mehanokemijska sinteza; dopiranje; fotokataliza
• Keywords (english): zincite; cadmium; mechanochemical synthesis; doping; photocatalysis
• Language: croatian
• URN:NBN: urn:nbn:hr:149:279789
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-05-26 13:30:32