TiO₂/Carbon Composites Prepared from Rice Husk and the Removal of Bisphenol A in Photocatalytic Liquid System

Abstract

The improved photocatalytic performance of a carbon/TiO2 composite was studied for the Bisphenol A (BPA) decomposition. Titanium tetraisopropoxide (TTIP) and a rice husk from Korea were heterogeneously mixed as the titanium and carbon sources, respectively, for 3 h at room temperature, and then thermally treated at 600 o C for 1 h in H2 gas. The transmission electron microscopy (TEM) images revealed that the bulk carbon partially covered the TiO2 particles, and the amount that was covered increased with the addition of the rice husk. The acquired carbon/TiO2 composite exhibited an anatase structure and a novel peak at 2θ = 32 o , which was assigned to bulk carbon. The specific surface area was significantly enhanced to 123 ~ 164 m 2 /g in the carbon/TiO2 composite, compared to 32.43 m 2 /g for the pure TiO2. The X-ray photoelectron spectroscopy (XPS) results showed that the Ti-O bond was weaker in the carbon/TiO2 composite than in the pure TiO2, resulting in an easier electron transition from the Ti valence band to the conduction band. The carbon/TiO2 composite absorbed over the whole UV-visible range, whereas the absorption band in the pure TiO2 was only observed in the UV range. These results agreed well with an electrostatic force microscopy (EFM) study that showed that the electrons were rapidly transferred to the surface of the carbon/TiO2 composite compared to the pure TiO2. The photocatalytic performance of the BPA removal was optimized at a Ti:C ratio of 9.5:0.5, and this photocatalytic composite completely decomposed 10.0 ppm BPA after 210 min, whereas the pure TiO2 achieved no more than 50% decomposition under any conditions.

Surface modification and immobilization in poly(acrylic acid) of Ag/ZnO for photocatalytic degradation of endocrine‐disrupting compounds

“…The overall achieved photodegradation percentages of BPA in the framework of this work are comparable to those reported in the literature under similar reaction conditions using composites. For instance, 80% of degradation of BPA (11.4 ppm) in 24 h using TiO 2 /zeolite, and 75% of degradation of BPA (15 ppm) using TiO 2 /carbon in 5 h . In the present study, 47% of BPA (10 ppm) was decomposed in 8 h using the 8% Ag/ZnO‐PAA composite.…”

Production of phenolics via photocatalysis of ball milled lignin–TiO2 mixtures in aqueous suspension

“…This is an evidence for strong surface attachment and interactions between TiO 2 and lignin, which is desired. Kim et al 36 also observed a similar peak in the XRD of TiO 2 -carbon composites using rice husk as the carbon precursor at high loading. The crystallite sizes of Aeroxide® TiO 2 , and TiO 2 in DM, WMH, WMA and WMW mixtures were similar, i.e.…”

Adsorption of Phenol on Mesoporous Carbon CMK-3: Effect of Textural Properties

“…[11][12][13][14][15][16] Recently phenols have also been removed with new adsorbents and/or reactions. [17][18][19] Mesoporous carbon, CMK-3 is a fascinating material and exhibits a high surface area, a large pore volume, narrow pore size distribution, and well-ordered mesoporous structure. 20,21 CMK-3 has been widely used as adsorbents for several chemicals including biomaterials such as L-histidine and vitamine E. [22][23][24][25][26][27][28] CMK-3, with or without modification, has also been used in the removal of phenol.…”