scholarly journals MODIFICATION OF TITANIUM DIOXIDE NANOPARTICLES WITH COPPER OXIDE CO-CATALYST FOR PHOTOCATALYTIC DEGRADATION OF 2,4-DICHLOROPHENOXYACETIC ACID

2016 ◽  
Vol 20 (1) ◽  
pp. 171-178 ◽  
Author(s):  
Leny Yuliati ◽  
Wai Ruu Siah ◽  
Nur Azmina Roslan ◽  
Mustaffa Shamsuddin ◽  
Hendrik O. Lintang
2017 ◽  
Vol 17 (2) ◽  
pp. 284 ◽  
Author(s):  
Leny Yuliati ◽  
Nur Azmina Roslan ◽  
Wai Ruu Siah ◽  
Hendrik Oktendy Lintang

2,4-dichlorophenoxyacetic acid (2,4-D) has been recognized as a possibly carcinogenic compound to human, therefore, 2,4-D should be treated before it is discharged to the environment. Photocatalytic degradation of 2,4-D has been proposed as one of the best methods that offer environmentally safe process. In the present research, titanium dioxide (TiO2) was modified with cobalt oxide (CoO) and tested for photocatalytic degradation of 2,4-D under UV light irradiation. Different amounts of CoO (0.1, 0.5, 1 and 5 mol%) were added onto TiO2 by an impregnation method. The photocatalytic reaction was monitored and analyzed by measurement of 2,4-D absorbance using UV spectrophotometer. After 1 h photocatalytic reaction, it was confirmed that the sample with low loading of 0.1 mol% gave the highest photocatalytic activity among the bare and modified TiO2 photocatalysts. The photocatalytic activity was decreased with the increase of CoO loading, suggesting that the optimum amount of CoO was an important factor to improve the performance of TiO2. Based on fluorescence spectroscopy, such addition of CoO resulted in the reduced emission intensity, which showed the successful decrease in the electron-hole recombination.


2019 ◽  
Vol 16 (32) ◽  
pp. 338-344
Author(s):  
Nikolay A. BULYCHEV ◽  
Lev N. RABINSKIY

The influence of the ultrasonic treatment of block copolymer solution on its solid-liquid interface behavior was investigated in detail. The surface modification of titanium dioxide nanoparticles in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymer by ultrasonic treatment was studied in order to get new approaches for the creation of hybrid composite materials or polymer coatings. The pigment surface modification by the above copolymer was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface were quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymer as achieved by ultrasonic treatment in comparison to conventional adsorption is a consequence of ultrasonically induced pigment surface activation. Two perspective avenues of the utilization of the discovered effects for creation of organic-inorganic composite materials are anticipated: the nanoparticles could first be treated by ultrasound in the presence of polymers and so create a surface modifying coating and the second option is an entrainment of the nanoparticles into the monomer matrix which can be polymerized afterward yielding a polymer with immobilized nanoparticles.


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