Enhanced photocatalytic activity for titanium dioxide by co-modification with copper and iron

Abstract

A copper(II) and iron(III) co-modified titanium dioxide nano material was prepared by a simple sol-gel process using titanium(IV) isopropoxide plus copper(II) and iron(III) nitrates as raw materials. The as-prepared nanocomposites were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy and photoluminescence spectra. The XRD results showed that the undoped TiO 2 nanoparticles mainly include anatase phase while the Cu, Fe-codoped TiO 2 nanoparticles showed a mixture of anatase phase with a small fraction of rutile phase displaying higher activity than the pure anatase phase. Optical characterization showed that the codoping with copper(II) and iron(III) resulted in a red shift of adsorption and lower recombination probability between electrons and holes, which were associated with high photocatalytic activity of the Cu, Fe-codoped TiO 2 nanoparticles under visible light (k [ 400 nm). The photocatalytic activity of the samples was tested by aqueous methyl orange degradation. The capability of the codoped catalyst was much higher than that of the pure TiO 2 catalyst under visible irradiation. A mechanism is proposed in order to account for the enhanced catalytic activity.

PREPARATION AND CHARACTERIZATION OF Cu-Fe/TiO2 PHOTOCATALYST FOR VISIBLE LIGHT DEEP DESULFURIZATION

“…It is noteworthy that the monometallic photocatalysts displayed the lowest DBT conversion of 18.95 % for Fe and 54.88 % for Cu compared to the bimetallic photocatalysts. This observation is similar to studies reported by Liu et al [24] and Zhang [25], where the photocatalytic activity of Cu-Fe co-doped TiO 2 was higher than that of undoped or singly doped photocatalyst. …”

“…A great deal of research has been conducted using Cu or Fe doped TiO 2 , but co-doped Cu and Fe onto TiO 2 is rarely reported. Liu et al [24] and Zhang [25] degraded organic dye pollutants, Reactive Black 5 (RB 5) and Methyl Orange (MO) in wastewater under UV [24] and visible light [25] radiation, respectively. They showed that co-doped Cu and Fe onto TiO 2 displayed significant enhancement in photodegradation of the organic dye pollutants compared to the un-doped TiO 2 .…”

Characterization and activity of visible light–driven TiO2 photocatalysts co-doped with nitrogen and lanthanum

“…The visible light source was a 500-W high-pressure xenon lamp equipped with a UV cutoff filter to completely remove the UV portion of the illumination (k \ 400 nm). UV illumination was provided by a 375-W mercury lamp with two main emission peaks at 185 and 254 nm [18]. After sonication of the suspension for 30 min to achieve the adsorption equilibrium, the lamp was turned on.…”

Photocatalytic Degradation of DIPA Using Bimetallic Cu-Ni/TiO2Photocatalyst under Visible Light Irradiation

“…Modification of titania by doping using transition metals has often been used to enhance its photocatalytic activity and to extend its absorption wavelength from the UV to visible region [8]. The use of Cu and Ni as bimetallic catalysts supported on different semiconductor materials has been reported as the effective method to improve the efficiency of various reactions like carbon dioxide hydrogenation [9], steam reforming of methane [10], liquid-phase glycerol hydrogenolysis by formic acid over Ni-Cu/Al 2 O 3 catalysts [11], decomposition of methane over Ni-SiO 2 and Ni-Cu-SiO 2 catalysts [12], photocatalytic reduction of nitrate [13], azo dye degradation using Cu-Zn/TiO 2 [8], Ni/TiO 2 [14] and Cu-Fe/TiO 2 [15] for methyl orange degradation, and Cu/TiO 2 for Orange II degradation [16]. …”