Photocatalytic Properties and Chemical Durability of CaO-B2O3-V2O5 Borovanadate Glasses

The aim of this paper is to investigate the photocatalytic properties and chemical durability of the CaO-B2O3-V2O5 glasses system. The latter were synthesized by the melt-quenching technique. The amorphous nature of the prepared borovanadate glasses has been confirmed with X-ray diffraction. The chemical durability measured from their weights before and after immersion in deionized water and hydrochloric acid indicated that replacing V2O5 with B2O3 improved the chemical durability. The observed increases in chemical durability might be explained by the increase in the glass transition temperature, due to stronger bonding in the structural network. The photocatalytic performance was assessed by the degradation of methylene blue (MB) dye under irradiation, and the evolution of dye degradation was analyzed by UV-visible spectrometry. The vanadium content in the glass, the amount of catalyst, and the initial dye concentration showed a variable effect on the degradation of the MB dye. The photodegradation of methylene blue by the photocatalysts was found to follow pseudo-first-order rate kinetics. The photocatalytic activity for all the prepared photocatalysts showed a higher degradation performance, and the results indicated that 40 CaO-30 B2O3-30 V2O5 has the highest removal efficiency of about 99% in 180 min.

Effect of pH on the Performance of Bi2O2CO3 Nanoplates for Methylene Blue Removal in Water by Adsorption and Photocatalysis

In this study, a facile low-temperature hydrothermal method was applied for the synthesis of bismuth subcarbonate nanoplates (Bi2O2CO3). The material was then characterized by FTIR, XRD, SEM, BET, and TGA. The applicability of Bi2O2CO3 was evaluated via the treatment of methyl blue (MB) in water by adsorption and photocatalytic degradation. The experiment results with different pH from 2 to 12 indicate that the pH of the solution affected the surface charge of the synthesized Bi2O2CO3, thus having strong effects on the adsorption and photocatalytic degradation abilities of Bi2O2CO3 for MB removal. In adsorption tests, pH 6–7 is the most suitable condition for the adsorption of Bi2O2CO3. In photocatalytic tests, Bi2O2CO3 had the highest and lowest efficiencies of 64.19% (pH 5) and 17.59% (pH 2), respectively, under UV irradiation for 300 min. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).