Activity of nanosized titania synthesized from thermal decomposition of titanium (IV) n-butoxide for the photocatalytic degradation of diuron

Abstract

Nanoparticles of anatase titania were synthesized by the thermal decomposition of titanium (IV) n-butoxide in 1,4-butanediol. The powder obtained was characterized by various characterization techniques, such as XRD, BET, SEM and TEM, to confirm that it was a collection of single crystal anatase with particle size smaller than 15 nm. The synthesized titania was employed as catalyst for the photodegradation of diuron, a herbicide belonging to the phenylurea family, which has been considered as a biologically active pollutant in soil and water. Although diuron is chemically stable, degradation of diuron by photocatalyzed oxidation was found possible. The conversions achieved by titania prepared were in the range of 70-80% within 6 h of reaction, using standard UV lamps, while over 99% conversion was achieved under solar irradiation. The photocatalytic activity was compared with that of the Japanese Reference Catalyst (JRC-TIO-1) titania from the Catalysis Society of Japan. The synthesized titania exhibited higher rate and efficiency in diuron degradation than reference catalyst. The results from the investigations by controlling various reaction parameters, such as oxygen dissolved in the solution, diuron concentration, as well as light source, suggested that the enhanced photocatalytic activity was the result from higher crystallinity of the synthesized titania. q

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

“…Titanium n-butoxide in 1,4-butanediol formed anatase nanocrystals of about 10-15 nm in diameter after solvothermal reaction. [155,156] When heating titanium n-butoxide in toluene, only amorphous products were obtained. [156] Ethylene glycol reacts with titanium n-butoxide to titanium glycolate, which can easily be transformed into crystalline anatase nanowires by calcination.…”

Fabrication and characterization of neat and aluminium-doped titanium (IV) oxide fibers prepared by combined sol–gel and electrospinning techniques

“…Titania is a wide bandgap semiconductor with many interesting properties, such as transparency to visible light, high refractive index and low absorption coefficient. Other than these properties, it has been known to be an excellent photo-catalyst for the decomposition of various organic substances that include certain pesticides [3]. This pertains titania as excellent candidate for the treatment of agricultural waste water [4].…”

Radiation-induced reduction of diuron by gamma-ray irradiation

“…Diuron, a herbicide belonging to the phenylurea family, is chemically stable [1] and considered priority substances by the European Union Water Framework Directive (Directive 2000/60/EC) [2]. It could pollute water bodies through agricultural runoffs and wastewaters generated from diuron manufacturing plants [3].…”

“…Diuron could be completely mineralised by electrochemical technology and passivation of the electrode surface was not observed [7]. Photocatalytic methods and photo-Fenton were used by many researchers to remove diuron [1,[8][9][10][11][12][13][14][15][16][17][18]. 100% of chlorine could be recovered as chloride and 90% of mineralization was reached.…”