Carbon Nitride/TiO2 Nanocomposite in Treatment of Water Contaminated with Phenol

Abstract

A nanocomposites (CNTi) of carbon nitride (CN) and TiO2 nanoparticles (Ti) of different mass ratios were prepared by a hydrothermal treatment method and characterized using X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflectance spectroscopy (DRS) and Transmission Electron Spectroscopy (TEM). UV-Vis diffuse spectrum showed that the CNTi composites exhibited absorption in the visible light range. The kinetics of the phenol degradation using the as-prepared nanocomposite photocatalyst compared to the bare TiO2 nanoparticles was tested using Xenon lamps (mainly a visible light source) as a photoexcitation source in presence and absence of H2O2 and/or O3. The photodegradation of phenol was evaluated using UV spectrophotometer and total organic carbon (TOC). It was revealed that the photocatalytic activity of the CNTi composites significantly higher than TiO2 nanoparticles. Furthermore, 0.1CNTi composite showed the best phenol degradation when H2O2 and O3 were simultaneously used in which the degradation percentage of phenol was more than 90% within 30 min. Table 1 shows Rate constant, rate coefficient, degradation % (%D) and degradation % from TOC of TiO2, 0.1CNTi, 0.5CNTi, I CNTi in presence and absence of H2O2, 0.1CNTi with O3 and 0.1CNTi with both H2O2 and O3 parameter Catalyst TiO2 0.1% CNTi 0.5CNTi 1CNTi 0.1CNTi + O3 0.1CNTi + H2O2 + O3 - + H2O2 - + H2O2 - + H2O2 - + H2O2 r 0.021 0.030 0.032 0.056 0.030 0.051 0.023 0.043 0.038 0.080 R2 0.99 0.99 1.00 1.00 0.99 1.00 1.00 1.00 0.99 0.99 % D 49.1 61.3 62.6 81.2 60.7 77.8 49.7 72.9 69.1 91.4 TOC 54.4 72.8 63.1 81.3 59.9 78.0 49.9 73.0 71.08 92.1 Table 1: Rate constant, rate coefficient, degradation % (%D) and degradation % from TOC of TiO2, 0.1CNTi, 0.5CNTi, I CNTi in presence and absence of H2O2, 0.1CNTi with O3 and 0.1CNTi with both H2O2 and O3