Synthesis, characterization and properties of sulfate-modified silver carbonate with enhanced visible light photocatalytic performance.

Sulfate-modified Ag2CO3 was successfully synthesized via a simple precipitation method. Its visible light photocatalytic performance against the removal of Orange G was found to be significantly enhanced in comparison with the one of pure Ag2CO3. While SO42--Ag2CO3 ensured a removal efficiency of 100% of OG within 30 min, the unmodified Ag2CO3 exhibited a degradation threshold at hardly 60%. Likewise, the degradation rate constant in the presence of SO42--Ag2CO3 photocatalyst was assessed to be twice that determined upon the involvement of pristine Ag2CO3. Furthermore, Total Organic Carbon (TOC) measurements evidenced the occurrence of a quasi-total mineralization of the dye pollutant upon the use of SO42--Ag2CO3 photocatalyst. Scavenger experiments highlighted the dominant role of photo-induced h+ along with ˙O3- ozonide radicals in the OG photocatalytic oxidation mechanism. Reuse cycles revealed that the modification by SO42- is a promising route to improve the stability of silver carbonate against photocorrosion. All these improvements could be ascribed to electronic transfer from the upper SO42- HOMO to the lower Ag2CO3 conduction band.

The relationship of structure, thermal and water vapor permeability barrier properties of poly(butylene succinate)/organomodified beidellite clay bionanocomposites prepared by in situ polycondensation.

The exploitation of beidellite clay (BDT), used as a nanofiller in the preparation of poly(butylene succinate) (PBS)/organoclay biodegradable nanocomposites, was investigated. A series of bionanocomposites with various loadings of the organoclay (3CTA-BDT) were prepared by in situ polycondensation reaction between succinic anhydride (SuAh) and 1,4-butanediol (1,4-BD) at atmospheric pressure in refluxing decalin with azeotropic removal of water, and the reaction was catalyzed by non-toxic bismuth chloride (BiCl3). X-ray diffraction (XRD) and scanning electron microscopy (SEM) results showed that 3CTA-BDT was likely exfoliated and well dispersed in PBS matrix. Thermal properties (TGA, DSC and thermal conductivity), contact angle measurements and water vapor sorption behavior of the corresponding nanocomposites were also discussed. Compared to pure PBS, a significant reduction of the diffusion coefficient and the water vapor permeability (WVP) by 44 and 37%, respectively, was observed by adding only 5 wt% of 3CTA-BDT. These results could make these bionanocomposites suitable materials for food packaging application.