Comparison of the photoactivity of several semiconductor oxides in floating aerogel and suspension systems towards the reduction of Cr(Ⅵ) under visible light

摘要

A massive amount of research has been done over the last three decades to develop photoactive materials which could be suitable for real-world use in water remediation sector. Water-floating photocatalysts could be one of the best options due to their technological characteristics in terms of efficiency and reasonability including a high oxygenation of the photocatalyst surface, a fully sunlight irradiation, easy recovery and reuse. In the present study, aerogel water-floating based materials were fabricated using poly(vinyl alcohol) and polyvinylidene fluoride as a polymer platform, and loaded with different semiconductors such as g-C3N4, MoO3, Bi2O3, Fe2O3 or WO3. The photocatalytic efficiencies of aerogel floating materials and the suspension of above-mentioned semiconductors were compared evaluating the photoreduction of Cr(VI) under visible light (lambda 420 nm). The results showed that Fe2O3 suspension was the most efficient but the slowest in floating system. On the contrary, g-C3N4 exhibited a good performance in suspension system, and on top of that it was very effective in floating system, wherein it ensures a total reduction of 10 ppm-Cr(VI) to Cr(III) within 20 min.