Nanokompoziti na bazi polianilina i titan (IV)-oksida: sinteza, karakterizacija i primena u fotokatalizi

Abstract

Predmet istraživanja ove doktorske disertacije podrazumeva sintezu nanokompozita na bazi polianilina (PANI) i nanočestica titan (IV)‐oksida (TiO2) različitih oblika novom metodom, njihovu karakterizaciju većim brojem fizičkohemijskih metoda, kao i ispitivanje mogućnosti njihove primene u fotokatalizi. PANI/TiO2 nanokompoziti sintetisani su novim, ekonomičnim postupkom hemijske oksidativne polimerizacije anilina amonijum peroksidisulfatom u vodi, bez dodatka kiseline, kalupa i površinskih modifikatora, a u prisustvu nanočestica TiO2. Optimizacijom sinteze nanokompozita kroz variranje polaznog molskog odnosa anilina i TiO2 pronađeni su uslovi za dobijanje PANI/TiO2 nanokompozita u kojima su prisutne polianilinske nanostrukture. U disertaciji je ispitan uticaj nanočestica TiO2 na tok, brzinu i prinos reakcije polimerizacije anilina kao i na morfologiju, strukturu, provodljivost i magnetna svojstva polianilina. U cilju izučavanja potencijalne primene sintetisanih nanokompozita, ispitivana je sposobnost polianilina da senzitizira i pospeši fotokatalitičke procese na površini nanočestica TiO2. Rad se tematski može podeliti u tri celine i to: 1. Sinteza i karakterizacija nanokompozita na bazi polianilina i koloidnih nanočestica TiO2; 2. Sinteza i karakterizacija nanokompozita na bazi polianilina i nanotuba TiO2; 3. Ispitivanje fotokatalitičke aktivnosti nanokompozita na bazi polianilina i koloidnih nanočestica TiO2. Prvi deo teze odnosi se na ispitivanje svojstava nanokompozita sintetisanih hemijskom oksidativnom polimerizacijom anilina, uz pomoć amonijum peroksidisulfata, u prisustvu koloidnih nanočestica TiO2 (d = 4, 5 nm), bez dodatka...

The subject of this PhD thesis is the synthesis of nanocomposites based on polyaniline (PANI) and titanium (IV) oxide (TiO2) by a novel method, without added acids, templates and surfactants, their characterization by various physicochemical methods, as well as an investigation of their potential application in the field of photocatalysis. PANI/TiO2 nanocomposites were synthesized by a novel, economical method of oxidative polymerization of aniline with ammonium peroxydisulfate in water, without added acid, in the presence of shaped TiO2 nanoparticles. The optimization of polymerization process was done by varying initial mole ratio of aniline/TiO2. The aim was to find optimal conditions for the synthesis of PANI/TiO2 nanocomposites containing polyaniline nanostructures. Influence of TiO2 nanoparticles on the course, rate and yield of polymerization process of aniline, as well as their influence on the morphology, structure, electrical conductivity and magnetic properties of polyaniline is examined. Moreover, potential application of PANI/TiO2 nanocomposites in photocatalysis and ability of polyaniline to sensitize TiO2 nanoparticles are investigated. Topic of this work can be divided into three main units: 1. Synthesis and characterization of nanocomposites based on polyaniline and colloidal TiO2 nanoparticles; 2. Synthesis and characterization of nanocomposites based on polyaniline and TiO2 nanotubes; 3. The study of photocatalytic activity of nanocomposites based on polyaniline and colloidal TiO2 nanoparticles. The first part of the thesis refers to the investigation of properties of nanocomposites synthesized by the chemical oxidative polymerization of aniline with ammonium peroxydisulfate, in the presence of colloidal TiO2 nanoparticles (d=4, 5 nm), without added acid. As a reference sample, pure polyaniline...