An efficient eco advanced oxidation process for phenol mineralization using a 2D/3D nanocomposite photocatalyst and visible light irradiations

Abstract

Nanocomposites (CNTi) with different mass ratios of carbon nitride (C3N4) and TiO2 nanoparticles were prepared hydrothermally. Different characterization techniques were used including X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), transmission electron spectroscopy (TEM) and Brunauer-Emmett-Teller (BET). UV-Vis DRS demonstrated that the CNTi nanocomposites exhibited absorption in the visible light range. A sun light - simulated photoexcitation source was used to study the kinetics of phenol degradation and its intermediates in presence of the as-prepared nanocomposite photocatalysts. These results were compared with studies when TiO2 nanoparticles were used in the presence and absence of H2O2 and/or O3. The photodegradation of phenol was evaluated spectrophotometrically and using the total organic carbon (TOC) measurements. It was observed that the photocatalytic activity of the CNTi nanocomposites was significantly higher than that of TiO2 nanoparticles. Additionally, spectrophotometry and TOC analyses confirmed that degraded phenol was completely mineralized to CO2 and H2O with the use of CNTi nanocomposites, which was not the case for TiO2 where several intermediates were formed. Furthermore, when H2O2 and O3 were simultaneously present, the 0.1% g-C3N4/TiO2 nanocomposite showed the highest phenol degradation rate and the degradation percentage was greater than 91.4% within 30 min.

Toward an Accurate Spectrophotometric Evaluation of the Efficiencies of Photocatalysts in Processes Involving Their Separation Using Nylon Membranes

“…Further experiments focused on changing the applied pressure during the filtration process of 5 mL of different solutions of rhodamine B and phenol red at different concentrations of 5, 10, and 20 ppm, using a membrane filter (Figure 4a,b). It is worth mentioning that the choice of the concentrations (20 and 10 ppm) was based on the concentrations reported in the literature [7,17,[19][20][21]. A high vacuum (i.e., low pressure and high suction power) enhanced the removal of the dyes in all cases.…”

“…Qianqian et al, Bai et al, and Liu et al have used centrifugation for their nanomaterials; however, these techniques require several media transfers [10][11][12]. Filtration can be achieved using different types of cellulose filter papers and microporous membranes [1,9,[13][14][15][16][17][18]. Among the commonly used membranes are nylon membranes [7,17,[19][20][21] which will be used in this study.…”

Eco-friendly highly efficient BN/rGO/TiO2 nanocomposite visible-light photocatalyst for phenol mineralization

“…These two materials attracted much attention due to their exceptional electronic features (Wei et al 2011 , Liu et al 2017 ). We proved, earlier, that a photocatalyst from TiO 2 and reduced graphene oxide (rGO) (Al-Kandari et al 2015a , 2015b , Abdullah et al 2016 , Al-Kandari, Abdullah et al 2016 , Al-Kandari, Abdullah et al 2016 , Al-Kandari et al 2017a , 2017b ) degrades a variety of organic compounds efficiently under simulated sunlight. In this respect, we found that 0.1% of rGO with TiO 2 yielded 63% of phenol degradation within 30 min in the presence of an eco-oxidant, H 2 O 2 (Al-Kandari et al 2017a , 2017b ).…”

Ecotoxicological Assessment of Thermally- and Hydrogen-Reduced Graphene Oxide/TiO2 Photocatalytic Nanocomposites Using the Zebrafish Embryo Model

“…Nevertheless, having a high electron-hole recombination rate and wide bandgap energy, TiO 2 cannot be excited under visible light irradiation (λ > 400 nm) [17,18]. To gain insight into this specific issue, intensive research work has been directed towards the development of visible light-responsive TiO 2 with high catalytic activity using co-catalysts such as carbon nitride or reduced graphene oxide (RGO) because of their exceptional electrical properties and controllable structures [17,19,20,21,22,23,24,25].…”