Synthesis And Photocatalytic Studies Of AC/CNT Incorporated TiO2 AND Cu Modified gC3N4
| dc.contributor.author | Muniandy, Langeswarran | |
| dc.date.accessioned | 2018-01-16T07:25:55Z | |
| dc.date.available | 2018-01-16T07:25:55Z | |
| dc.date.issued | 2017-08 | |
| dc.description.abstract | Alkali leached activated carbon (AC) was synthesized from rice husk (RH) using NaOH and KOH as activating agents. AC with maximum surface area of 2696 m2g-1 was obtained via chemical activation using KOH with an impregnation ratio of 1:5 (ratio of rice husk charcoal to KOH) at 850 °C for an hour under nitrogen (N2) aeration. All AC samples displayed broad peaks at 2θ = 24° and 44° indicating their amorphous structure with slight micro-crystalline features. The N2 adsorption desorption isotherm of the AC samples were identified as a combination of both type I and IV. Furthermore, the deconvolution of the C 1s signal for AC5K850N showed a peak at 284.4 eV for the C=C sp2 hybridized aromatic bonds. The XRD analysis of the pristine carbon nanotubes (CNTs) indicated a sharp peak at 2θ = 24° corresponding to the crystalline graphitic structure (002 plane). The XPS analysis indicated that that the CNTs consists mainly of sp2 hybridized C=C bonds. The synthesized AC (AC5K850N) and CNTs were used as dopants for anatase titania (TiO2) using cetyltrimethyl ammoniumbromide (CTAB) as a dispersant and anchoring agent in the photocatalytic studies of methylene blue (MB). It was found that 7 wt. % of AC was the optimum loading amount. Both 7AC-TiO2 and 7CNT-TiO2 performed 2.7 and 1.5 times faster than anatase TiO2 in the removal of MB (50 mg L-1) under UV irradiation. The catalysts were reused up to four cycles without significant loss of photocatalytic activity. The mechanism suggests that as the electron gets excited from the valence band of the TiO2, it would be trapped within the carbon particles, thereby reducing the recombination of the e-/h+. The electrons which were trapped within the carbon particles would react with other reactive oxygen species (ROS) thus accelerating the photodegradation of MB. Copper modified graphitic carbon nitride (Cu-g-C3N4) was synthesized in a “one-pot” reaction from melamine and copper chloride. The copper species (Cu2+) was found to coordinate with the nitrogen atoms in Cu-g-C3N4. The oxidation of benzene using Cu-g-C3N4 resulted in 74.1% conversion and 97.5% selectivity towards phenol after 5 h at 80 °C. Two plausible reaction pathways were postulated for the reaction. In one, the generation of hydroxyl radicals upon the dissociation of hydrogen peroxide molecules due to the redox reaction of the Cu2+/Cu+ couple was postulated. The second was a non-free radical SN2 type mechanism. The catalyst, Cu-g-C3N4 was also used in the oxidation of toluene, styrene and cyclohexene resulting in a conversion of 43.6, 28.8 and 62.3% respectively. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/5401 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | Synthesis and photocatalytic studies Of AC/CNT | en_US |
| dc.subject | Incorporated TiO2 AND Cu Modified gC3N4 | en_US |
| dc.title | Synthesis And Photocatalytic Studies Of AC/CNT Incorporated TiO2 AND Cu Modified gC3N4 | en_US |
| dc.type | Thesis | en_US |
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