The Properties and Activity of TiO₂/beta‐SiC Nanocomposites in Organic Dyes Photodegradation

Abstract

The TiO /beta-SiC nanocomposites containing 0-25 wt. % of beta-SiC were synthesized by the sol-gel method and tested in the photodegradation of methylene blue and methyl orange water solutions. With the increase in SiC content, only a slight decrease in energy band gap was observed (3.19-3.12 eV), together with significant increase in the surface area of the catalysts (42.7-80.4 m g ). In the synthesized material, the anatase phase of TiO was present in the form of small agglomerates resulting from the mechanical mixing process. In the process conditions (catalyst concentration 0.5 g L , initial dye concentration 100 ppm, light source 100 W UV-Vis lamp), we have observed no signs of catalyst deactivation. The significantly higher photodegradation activity of methylene blue than methyl orange can be attributed to the preferable pH of the solution compared to pH and the cationic character of the first dye. In case of methyl orange, pH process conditions substantially limit the contact of the catalyst with the dye, as negatively charged surface of the catalysts repels the dissociated anionic dye molecules.

Membrane Emulsification Process as a Method for Obtaining Molecularly Imprinted Polymers

“…The total pore volume was derived from the amount of nitrogen gas adsorbed at a relative pressure close to unity, under the assumption that the pores were then filled with liquid adsorbate. The average pore diameter was obtained from the total pore volume and the BET surface area assuming cylindrical pore geometry [ 34 ]. The Barret–Joyner–Halenda (BJH) method with the Harkins–Jura equation and Faas correction was used to determine the pore size distribution (PSD) in the range of mesopores [ 35 , 36 , 37 ].…”

Acesulfame K Photodegradation over Nitrogen-Doped TiO2

“…Photodegradation was performed using a closed system with an inner-irradiation-type quartz reactor, presented in our previous work [42]. A medium pressure mercury lamp (power of 450 W, Ace Glass Inc., Vineland, NJ, USA) was used as the light source.…”

Facile Synthesis of BiOI Nanoparticles at Room Temperature and Evaluation of their Photoactivity Under Sunlight Irradiation

“…Generally, photocatalysis is a reaction which utilizes light to produce strong oxidative species and reactive holes with high reactivity tendency on a semiconductor surface to convert resistant organic materials into the inert components (e.g. CO 2 , H 2 O, phosphate, halide ions) . Titanium dioxide (TiO 2 ) is one of the most important semiconductor photocatalysts due to its unique properties such as biological and chemical inactivity, high oxidative power, nontoxicity and high stability .…”

“…CO 2 , H 2 O, phosphate, halide ions) . Titanium dioxide (TiO 2 ) is one of the most important semiconductor photocatalysts due to its unique properties such as biological and chemical inactivity, high oxidative power, nontoxicity and high stability . However, TiO 2 is optically active in UV region ( λ < 400 nm) due to its limited optical properties (a band gap of 3.2 eV, fast recombination of electron–hole pair and so forth) .…”