Comparative efficiency of TiO₂ nanoparticles in suspension vs. immobilization into P(VDF–TrFE) porous membranes

Abstract

Optimized photocatalytic membranes based on TiO2 and NaY immobilized into P(VDF–TrFE) have been developed showing a degradation efficiency of 96%.

Solution mixing preparation of PVDF/ZnO polymeric composite films engineered for heterogeneous photocatalysis

“…However, for 3 g or more of photocatalyst, there is no significant increase in photocatalytic efficiency. This is a result frequently obtained in the processes of immobilization of photocatalysts . Apparently, upon reaching a given photocatalyst amount, the larger immobilized mass does not generate a greater number of active sites available for the photocatalytic reaction.…”

“…Although there are fewer reports on the inclusion of photocatalysts for environmental remediation through advanced oxidation processes (AOPs), researchers have been long studying the inclusion of photocatalyst for membrane performance and properties enhancement and some conclusions can be adapted for the photocatalytic property. Among them, the photocatalyst mass was the most studied variable.…”

A novel poly(vinylidene fluoride) composite membrane for catalysis and separation

“…Different from PVDF membrane, an additional C@O stretching vibration absorption at 1,730 cm 21 appears in the PVDF/PMAA blend membrane and composite membranes, confirming that PMAA is incorporated [20]. In addition, all the membranes show strong characteristic peaks at 840 and 1,280 cm 21 , indicating the PVDF matrixes have b-crystalline phase [24,25]. This crystalline phase is considered to the main form crystal of PVDF matrixes when membrane is formed from solutions in DMF solvent at a temperature lower than 308C [26,27].…”

Fotodegradação Solar De Efluente Têxtil Utilizando Tio2 Imobilizado Em Alumínio Reciclado

“…O uso do H2O2 combinado com catalisadores como o TiO2 torna a degradação mais efetiva, pelo impedimento da recombinação de elétrons-lacuna e pelo fornecimento de radicais hidroxila adicionais (Rocha et al, 2011;Vilar et al, 2011). Pode-se justificar uma maior eficiência do sistema com TiO2 suportado pois, apesar de se ter uma perda na área de contato superficial do catalisador com a radiação ao realizar a imobilização, sistemas com catalisador suportado podem se tornar equivalentes aos sistemas em suspensão dependendo de sua configuração (Martins et al, 2016), o que foi o caso deste trabalho. Além disso, a quantidade de catalisador em suspensão utilizada nos experimentos pode ter causado impedimento na passagem de luz, diminuindo a superfície ativa do catalisador e, com isso, gerando menores taxas de degradação; esse efeito foi observado no trabalho de Kazemi et al (2016), que estudou a remoção do corante têxtil azul de metileno por poliacrilamida contendo nanopartículas de TiO2.…”