Abstract
A Zn,Al layered double hydroxide (LDH), with the hydrotalcite structure and the mixed oxide obtained upon its calcination at 650 °C, was tested in the adsorption and photocatalytic degradation of 4-Nitrophenol in aqueous solution. The Zn,Al LDH was fast and easily obtained by the coprecipitation method. Hydrothermal treatment under microwave irradiation was applied to compare the effect of the ageing treatment on the photocatalytic behavior. The efficiency of the synthetized solids was compared to that of a commercial ZnO. The ageing treatment did not improve the performance of the original samples in the degradation of 4-nitrophenol. The activity of the synthetized solids tested exceeded that observed for the reaction with commercial ZnO. The photocatalytic performance of the original non-calcined hydrotalcite is similar to that of commercial ZnO. The calcined hydrotalcite showed a better performance in the adsorption-degradation of the contaminant than ZnO, and its reusability would be possible as it recovered the hydrotalcite-like structure during the reaction.
Highlights
The use as photocatalysts of layered systems, and the mixed oxides derived from them by thermal decomposition, has been described in the literature, they are not as widely used as TiO2 .Discoloration of methylene blue using hydrotalcite-based catalysts was studied by Abderrazek et al [1], while Barhoum et al [2], among others, reported the photocatalytic activity of ZnO particles in the oxidation of methanol
Zhang et al [3] synthetized nanostructured Zn-Al layered double hydroxides and have tested their photocatalytic activity, and that of the mixed oxides formed upon their calcination under different conditions, on the photodegradation of rhodamine dye in aqueous solutions
Hydrotalcite is a layered hydroxycarbonate belonging to the so-called layered double hydroxides (LDHs) family, sometimes identified as anionic clays because of the similarity between their structure and that of clays, but with negative layers, electrically balanced by anions intercalated in the interlayers
Summary
The use as photocatalysts of layered systems, and the mixed oxides derived from them by thermal decomposition, has been described in the literature, they are not as widely used as TiO2 .Discoloration of methylene blue using hydrotalcite-based catalysts was studied by Abderrazek et al [1], while Barhoum et al [2], among others, reported the photocatalytic activity of ZnO particles in the oxidation of methanol. Zhang et al [3] synthetized nanostructured Zn-Al layered double hydroxides and have tested their photocatalytic activity, and that of the mixed oxides formed upon their calcination under different conditions, on the photodegradation of rhodamine dye in aqueous solutions. Hydrotalcite is a layered hydroxycarbonate belonging to the so-called layered double hydroxides (LDHs) family, sometimes identified as anionic clays because of the similarity between their structure and that of clays, but with negative layers, electrically balanced by anions intercalated in the interlayers. These solids are transformed into well dispersed mixed oxides after being calcined at temperatures at or above 500 ◦ C. There are multiple synthesis routes to produce these solids [8,9,10]; among them, the co-precipitation method is the less expensive and the simplest one, and it is applied to manufacture this material at a large scale [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
