Enhanced Photocatalytic Activity of TiO₂ Nanosheets by Doping with Cu for Chlorinated Solvent Pollutants Degradation

Abstract

Photocatalytic of Cu-TiO2 was tested for the degradation of 1.1.1-trichloroethane, tetrachloroethene, and trichloroethene in aqueous phase under UV illumination. Results indicated fast degradation rate of pollutants over TiO2 doped with 0.5 wt % of Cu compared to undoped TiO2 and Degussa P25. Fast degradation of nitrobenzene, a probe of hydroxyl radicals (•OH), over Cu-TiO2 suggested high concentration of •OH generated in UV/Cu-TiO2 system. Cu-TiO2, synthesized by simply hydrothermal solution containing tetrabutyl-titanate, hydrofluoric acid, and cupric nitrate, was characterized by X-ray diffraction, Brunauer–Emmett–Teller, transmission electron microscopy, and X-ray photoelectron spectroscopy (XPS). Results showed that Cu-TiO2 was in anatase form and consisted of well-defined sheet-shaped structures having a rectangular outline. XPS analysis showed that surface state of the synthesized products was not modified by Cu doping and Cu was in Cu+ oxidation state. Moreover, Cu-TiO2 product showed good stability through five cycles reuse in trichloroethene photodegradation, suggesting a great potential for its application in chlorinated solvent contaminated groundwater remediation.

Photocatalytic Selective Oxidation of Ammonia in a Semi-Batch Reactor: Unravelling the Effect of Reaction Conditions and Metal Co-Catalysts

“…On the other hand, one of the main efficiency issues in photocatalytic processes is the fast electron-hole recombination (~10 −9 s). In order to overcome this problem, semiconductors are often loaded with noble metal nanoparticles [22][23][24]. These nanoparticles have the Fermi level located near the energy potential of the semiconductor conduction band, and therefore they are able to capture photopromoted electrons.…”

Semi‐Batch Photocatalytic Reduction of Nitrates: Role of Process Conditions and Co‐Catalysts

“…The modification of TiO 2 structure either by different synthesis techniques and changing the crystalline phases [28,29] or the addition of either metal or non-metal elements have been proposed as strategies to improve the photocatalytic activity and to enhance light harvesting. Co-catalysts, such as Pd, Pt, Au and Cu usually improve the photocatalytic activity of TiO 2 either by reducing the band gap and shifting light harvesting towards the visible part of the spectrum, with the ultimate goal of using solar radiation [23,24,30,31] and/or enhancing charge separation by easing the charge-transfer between the metal and the semiconductor. [32,33] Meanwhile, noble metals, such as Au and Ag nanoparticles exhibit higher light absorption due to resonance between the incident electromagnetic wave and the collective motion of conduction (free) electrons at metal surfaces, called localized surface plasmon resonance (LSPR), which is advantageous to absorb white light.…”

Enhanced Hydrogen Evolution in the Presence of Plasmonic Au-Photo-Sensitized g-C3N4 with an Extended Absorption Spectrum from 460 to 640 nm

“…Various semiconductor photocatalysts, such as TiO 2 , ZnO, and SrTiO 3 have been widely studied for the photocatalytic production of hydrogen from water splitting. [ 5 – 9 ] These semiconductor photocatalysts have been so far demonstrated to be active in water splitting, however most of them are responsive to UV irradiation only. The relatively low quantum efficiency and extremely insufficient utilization of solar light restrict further application of semiconductor catalysts.…”