Development of a TiO2/Sepiolite Photocatalyst for the Degradation of a Persistent Organic Pollutant in Aqueous Solution

Abstract

A clay-based TiO2 nanocomposite material was synthesized by a facile method, to investigate its structure and photocatalytic efficiency. The supported TiO2 nanoparticles were generated using a sol-gel method, and subsequently, mixed with a suspension of sepiolite. The material was recovered in powder form (Mc-80) and then calcined to properly arrange the crystal lattice of the TiO2 particles for use in heterogeneous photocatalysis (Mc-80-500). A powder X-ray diffractogram of Mc-80-500 revealed a dispersion of anatase and rutile phase TiO2 particles on the clay surface, exhibiting a size in the order of 4–8 nm. TEM images of Mc-80-500 confirmed the presence of isolated TiO2 beads on the surface of the fibrous sepiolite. The specific surface area of Mc-80-500 was larger than that of raw sepiolite and that of free TiO2 nanoparticles. Mc-80-500 was found to be more efficient in heterogeneous photocatalysis compared to other TiO2 materials based on sepiolite. Total depollution of a reactive dye (Orange G) was achieved after 1 h irradiation time, which is relatively quick compared to previous reports. The photocatalyst material can be washed with distilled water without chemical additives or calcination, and can be reused several times for photocatalysis, without loss of efficiency.

Fabrication of samarium doped MOF-808 as an efficient photocatalyst for the removal of the drug cefaclor from water

“…The consistent mass loss curve represented the decomposition of metal organic framework. 45 TGA data of functionalized MOF showed a continuous weight loss up to 380 °C. This temperature is ascribed to the removal of solvent, water, and collapse of framework with formation of inorganic oxide as well as organic species.…”

Cerium-Doped TiO2 and Sepiolite Nanocomposites for Tetracycline Inactivation in Water Treatment

“…where F(R ∞ ) is called the Kubelka−Munk function, R ∞ refers to reflectance when the sample has infinite thickness, hv is the photon energy, C 1 is the constant of proportionality, E g is the band gap, n is the constant of electronic transitions. 34 The degree of mineralization of organic matter was assessed by analyzing TOC (Total Organic Carbon) using a Shimadzu TOC-L instrument using the catalytic combustion oxidation method at 953.15 K.…”

“…Diffuse reflectance analysis was performed with a Shimadzu UV–visible spectrophotometer, model UV-3600, equipped with a diffuse reflectance accessory, monitoring the region between 200 and 800 nm. The bandgap energy (E g ) was calculated using Equation , based on the method proposed by Kubelka and Munk (1931): ( F ( R ∞ ) h v false) 2 = C 1 false( h v − E g false) n where F(R ∞ ) is called the Kubelka–Munk function, R ∞ refers to reflectance when the sample has infinite thickness, hv is the photon energy, C 1 is the constant of proportionality, E g is the band gap, n is the constant of electronic transitions …”

Improvement of Photocatalytic Performance by Building Multiple Heterojunction Structures of Anatase–Rutile/BiOI Composite Fibers

“…With the deepening of semiconductor research, its related technology has been applied in more and more different fields, and semiconductor composite scheme has also been applied in TiO 2 modification technology by many scholars. In order to solve the problem of poor photocatalytic activity of TiO 2 , the most commonly used methods are ion doping [ 11 ], surface modification [ 12 ], and semiconductor composite [ 13 ]. Semiconductor composite heterojunction formation is widely concerned as an effective method to improve photocatalytic activity.…”