diplomsko delo
Abstract
Plastoviti dvojni hidroksidi (LDH, angl. layered double hydroxides) so
raznoliki materiali z značilno plastovito strukturo. Zaradi delne zamenjave dvovalentnih
kovinskih kationov s trivalentnimi so sestavljeni iz pozitivno nabitih plasti hidroksida,
med plasti pa se za izenačitev naboja interkalirajo anioni. Tovrstna struktura tem
materialom omogoča izmenjavo interkaliranih anionov, kar uporabljamo za določene
aplikacije. Nekateri LDH so tudi polprevodniki, kar jim daje fotokatalitske lastnosti. S
toplotno obdelavo iz LDH dobimo mešane kovinske okside.
Namen mojega diplomskega dela je bila sinteza cink-aluminijevih LDH z interkaliranimi
kloridnimi ioni, ter cink-aluminijevih LDH z interkaliranimi karbonatnimi ioni. Sintezo
smo izvedli z metodo soobarjanja pri konstantnem pH. Iz pripravljenih LDH smo s
peptizacijo pripravili sol, iz katerega smo s tehniko potapljanja pripravili tanke plasti, ki
smo jih nato toplotno obdelali. Strukturo pripravljenih LDH v praškasti obliki in tankih
plasti smo preverili z metodo rentgenske praškovne difrakcije.
Določili smo sorpcijske in fotokatalitske lastnosti tankih plasti, ki smo jih termično
obdelali pri 600 °C. V raztopino barvila Plasmocorinth B znane začetne koncentracije
smo potopili pripravljene plasti in z UV-Vis spektrofotometrijo spremljali časovno
odvisnost zniževanja koncentracije barvila. Potek absorpcije smo določali v temi,
fotokatalitsko učinkovitost pa med izpostavitvijo opisanega sistema UV ali vidni svetlobi.
Izkazalo se je, da so toplotno obdelane tanke plasti Zn-Al LDH z interkaliranimi
karbonatnimi ioni učinkovit sorbent in deloma tudi fotokatalizator. Toplotno obdelane
plasti Zn-Al LDH z interkaliranimi kloridnimi ioni so slab sorbent, a zelo učinkovit
fotokatalizator.
Keywords
plastoviti dvojni hidroksidi;LDH;cink;tanke plasti;sorpcija;fotokataliza;diplomska dela;
Data
Language: |
Slovenian |
Year of publishing: |
2022 |
Typology: |
2.11 - Undergraduate Thesis |
Organization: |
UL FKKT - Faculty of Chemistry and Chemical Technology |
Publisher: |
[K. Trobec] |
UDC: |
54-36:620.1(043.2) |
COBISS: |
138788099
|
Views: |
43 |
Downloads: |
13 |
Average score: |
0 (0 votes) |
Metadata: |
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Other data
Secondary language: |
English |
Secondary title: |
Absorption and photocatalytic properties of zinc-aluminium layered double hydroxide thin films |
Secondary abstract: |
Layered double hydroxides (LDH) are diverse materials with a characteristic
layered structure. As a result of the partial exchange of divalent cations with trivalent
ones, they consist of positively charged hydroxide layers, while anions are intercalated
between the layers to neutralize the charge. This structure gives these materials the ability
to exchange intercalated anions, which can be used for certain applications. Some LDHs
are also semiconductors, which leads to their photocatalytic properties. We can produce
mixed metal oxides by calcination of LDHs.
The aim of my diploma work was to synthesize zinc-aluminium LDH with intercalated
chloride ions, and zinc-aluminium LDH with intercalated carbonate ions. The synthesis
was carried out by the coprecipitation method at constant pH. Sols were prepared from
the synthesized LDHs by peptization, from which thin films were prepared by dip-coating
technique. The thin films were then thermally treated. The structure of the prepared LDHs
was determined by X-ray diffraction.
The sorption and photocatalytic properties of the thin films, thermally treated at 600°C,
were determined. The prepared thin films were immersed in a solution of Plasmocorinth
B dye of known concentration. Then the change of dye concentration with increasing time
was monitored using UV-Vis spectrophotometry. Sorption process was performed in the
dark, while the determination of photocatalytic properties was performed by irradiating
the described system with UV or visible light.
It was found that calcined thin films of Zn-Al LDH, intercalated with carbonate ions, are
an effective sorbent and a partially effective photocatalyst. Thermally treated thin films
of Zn-Al LDH with intercalated chloride ions are an ineffective sorbent, but a very
effective photocatalyst. |
Secondary keywords: |
layered double hydroxide;thin films;sorption;photocatalysis;Aluminijev hidroksid;Univerzitetna in visokošolska dela; |
Type (COBISS): |
Bachelor thesis/paper |
Study programme: |
1000373 |
Embargo end date (OpenAIRE): |
1970-01-01 |
Thesis comment: |
Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Kemija |
Pages: |
37 str. |
ID: |
17491044 |