Structural and optical properties of Cu-substitution of NiAl2O4 and their photocatalytic activity towards Congo red under solar light irradiation

Abstract

The present work focuses on the effect of Cu substitution on the crystal structure and photocatalytic activity of nano-spinel oxides Ni (1−x) Cu x Al 2 O 4 (x = 0.0-1.0). The synthesized compounds by co-precipitation route are characterized by X-ray diffraction, FT-IR, X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and UV-vis diffuse reflectance. The photocatalytic activity is followed by UV-vis spectroscopy and Electrochemical Impedance Spectroscopy in order to confirm the good performance of the catalyst and the charge separation of photogenerated (e − /h + ) pairs. The photocatalytic efficiency of the synthesized catalysts is investigated through the decomposition of Congo Red dye under solar light irradiation. The efficient catalyst is Ni 0.2 Cu 0.8 Al 2 O 4 with a removal conversion of 90.55% of the dye after 180 min. The parameters influencing the dye degradation like initial concentration are studied for the optimum degradation and the results have been discussed. This study shows that the adsorption kinetic of the Congo red has well followed the Langmuir isotherm model. The high photocatalytic activity of Ni 0.2 Cu 0.8 Al 2 O 4 can be attributed to the valence band of the catalyst which enhances the mobility of the photoexcited charge carriers.

Visible Light Sensitive SnO2/ZnCo2O4 Material for the Photocatalytic Removal of Organic Pollutants in Water

“…The SnO2 increase to 30 wt % of SnO2 leads to a small decrease of specific surface area and consequently a loss of activity compared to the 20 wt % sample, this observation can reinforce the fact that the activity is linked to the morphology of the sample. A comparison with literature shows that CR degradation is widely studied [25][26][27] but the conditions of testing are quite different from a work to another making the comparison difficult. In Srivind et al [25], the complete degradation of CR appears after about 3 h of illumination by light containing UV parts.…”

“…A comparison with literature shows that CR degradation is widely studied [25][26][27] but the conditions of testing are quite different from a work to another making the comparison difficult. In Srivind et al [25], the complete degradation of CR appears after about 3 h of illumination by light containing UV parts.…”

Pristine and Graphene-Quantum-Dots-Decorated Spinel Nickel Aluminate for Water Remediation from Dyes and Toxic Pollutants

“…Aluminates have high thermal stability, mechanical resistance, hydrophobicity and low surface acidity. Nickel aluminates are one of the most important aluminate materials, and have been studied for their many applications, including electrochemical sensing [1], pigments [2], catalysts [3][4][5][6][7], photocatalysts [8][9][10][11][12], magnetic [13] and refractory materials [14]. NiAl 2 O 4 has also attracted attention as a hydrogen storage material [15,16], oxygen carrier in combustion loop reactors [17] and as a component of supercapacitor electrode materials [18].…”

“…NiAl 2 O 4 has also attracted attention as a hydrogen storage material [15,16], oxygen carrier in combustion loop reactors [17] and as a component of supercapacitor electrode materials [18]. Very recently, attention has been focused on its photocatalytic performance [10][11][12]. First reports described the utilization of nickel-aluminum layered hydroxides for carbon dioxide conversion [19,20] and for dye degradation [21,22].…”

“…The photocatalytic activity of the nickel aluminate spinel against a series of dyes (i.e., rhodamine B (RhB), methylene blue (MB), methyl orange (MO), methyl red) was demonstrated by T. Tangcharoen et al [10]. In the past year, the enhanced photocatalytic performance of NiAl 2 O 4 was achieved by its substitution with copper, nickel and magnesium ions [11,12]. These photocatalytic tests were run against MB, MO and Congo red, both using ultraviolet and solar light irradiation.…”