Preparation, characterisation and activity evaluation of CaCO₃/ZnO photocatalyst

Abstract

The photocatalyst CaCO 3 /ZnO with high activity was prepared by coprecipitation method using (NH 4 ) 2 CO 3 , Zn(NO 3 ) 2 and Ca(NO 3 ) 2 as raw materials. The photocatalyst was characterised by X-ray powder diffraction, terephthalic acid photoluminescence probing technique (TA-PL), UV-vis diffuse reflectance spectroscopy and the fluorescence emission spectra. The photocatalytic activity of the photocatalyst was evaluated by photocatalytic oxidation of methyl orange and rhodamine B. The results showed that the photocatalytic activity of the photocatalyst was much higher than that of pure ZnO. The best mole ratio of Ca/Zn in the sample was 1 : 2, and its intensity of TA-PL was the strongest. The effect of heat treatment condition on the photocatalytic activity of the photocatalyst was investigated. The best preparation condition was about 650 C for 7 h. Compared with pure ZnO, the photoabsorption wavelength range of the CaCO 3 /ZnO extends towards visible light and improves the utilisation of the total spectrum. The possible mechanisms of influence of CaCO 3 on the photocatalytic activity of CaCO 3 /ZnO were also discussed.

The Synthesis of Y-zeolite-modified CaCO3-ZnO Nanocomposites as an Antibacterial Agent

“…The combination of ZnO with lower CaCO3 can increase activity as the crystal size decreases. Similar results were reported that CaCO3-ZnO with a mole ratio of 1:2 has better activity 19 compared to the mole ratios 1:1 and 2:1. The crystal size of CaCO3-ZnO was increased after being modified with Y-zeolite.…”

“…CaCO3-ZnO nanocomposites were synthesized using the coprecipitation method with modification 19 . CaCO3-ZnO nanocomposites (mole ratio 1:1) were prepared by mixing 50 mL calcium acetate 1 M and 50 mL zinc acetate dihydrate 1 M until homogeneous.…”

“…CaCO3-ZnO/Y-zeolite nanocomposites were synthesized using the coprecipitation method with modification 19 . Comparison of mole ratios in the synthesis of CaCO3-ZnO with the best antibacterial activity modified with Y-zeolite.…”

Photocatalytic removal of 2-chlorophenol from water by using waste eggshell-derived calcium ferrite

“…Additionally, the minor CaCO 3 phase in the 30Fe/QES photoactive material may promote the effective separation of the photogenerated electrons and holes, similar to another research work that indicated the improved photocatalytic degradation efficiencies of aqueous organic dyes (rhodamine B and methyl orange) over CaCO 3 /ZnO. 58 Furthermore, the 30Fe/QES was subjected to subsequent 2-CP removal runs without purication/ regeneration processes. It was found that the 30Fe/QES catalyst can be effectively reused, giving 2-CP removal efficiencies of 70.5% ± 0.99 in the 3rd cycle.…”

Synergy effect in the photocatalytic degradation of textile dyeing waste water by using microwave combustion synthesized nickel oxide supported activated carbon

“…Amidst numerous treatment processes employed to treat the textile dyeing effluents, heterogeneous photocatalysis emerges as the best, because it is a costeffective treatment process [10][11][12][13]. In the previous decade, many metal oxide semiconductors like TiO 2 , ZnO, and NiO were used as heterogeneous photocatalysts.…”