Dye Degradation Mechanisms Using Nitrogen Doped and Copper(II) Phthalocyanine Tetracarboxylate Sensitized Titanate and TiO₂ Nanotubes

Abstract

Several strategies have been used to increase the photocatalytic activity of titanate and titanium dioxide nanotubes (TiNTs and TiO 2 NTs) using visible light, including doping with nitrogen and sensitization with copper phthalocyanine. Additionally, TiNTs and TiO 2 NTs have been successfully used in catalysis mediated by hydrogen peroxide. In this work, we describe the synthesis of nitrogen doped and copper phthalocyanine sensitized TiNTs and TiO 2 NTs for photodegradation using visible light and for catalysis mediated by hydrogen peroxide. The combined effect of nitrogen doping and copper phthalocyanine sensitization promoted a quenching of the photocatalytic activity of the catalysts. However, the sensitization increased the catalytic effect of the catalysts compared with the nonsensitized species. These results suggest that the generation of the reactive species responsible for the dye degradation happens through different mechanisms, and the topic is discussed in this article.

Photocatalytic Efficiency of Metallo Phthalocyanine Sensitized TiO2 (MPc/TiO2) Nanocomposites for Cr(VI) and Antibiotic Amoxicillin

“…The peaks at around 1534-1408 cm −1 are referred to as -C=C stretching bands of aromatic groups for the phthalocyanine structure [7]. A broadband at approximately 3650-2800 cm −1 is typically assigned to Ti-O-H and O-H vibration of absorbed water molecules on TiO2 surface [62]. Stretching and vibration between Ti and O are ranked in the fingerprint region described at 1250 cm −1 and below this value.…”

“…stretching bands of aromatic groups for the phthalocyanine structure [7]. A broadband at approximately 3650-2800 cm −1 is typically assigned to Ti-O-H and O-H vibration of absorbed water molecules on TiO2 surface [62]. Stretching and vibration between Ti and O are ranked in the fingerprint region described at 1250 cm −1 and below this value.…”

Photocatalytic degradation of norfloxacin and its intermediate degradation products using nitrogen‐doped activated carbon–CuS nanocomposite assisted by visible irradiation

“…The low electrical conductivity of AC is improvable by doping N in the carbon structure; thus, it can improve adsorption and photodegradation process efficiency. In addition, it leads to a bandgap reduction between the valence and conduction bands of the semiconductor, reducing the energy needed to photogenerate electron–hole pairs …”

“…In addition, it leads to a bandgap reduction between the valence and conduction bands of the semiconductor, reducing the energy needed to photogenerate electron-hole pairs. [24] Response surface methodology (RSM) comprises a series of arithmetical and statistical methods that are established for the adaptation of empirical models to the obtained experimental data associated with experimental design. For this aim, linear or square polynomial functions are applied to explain the work studied and accordingly to investigate experimental conditions to reach optimal points.…”

Estudo de nanoestruturas de titanato sintetizadas pelo método hidrotérmico

“…Os melhores rendimentos de atividade fotocatalítica são obtidos em TNS protônicos após tratamento térmico e transição de fase para anatase (Yu et al, 2006;Shibata et al, 2007;Turki et al, 2013). Modificações, como dopagem com N (Souza et al, 2014(Souza et al, , 2016Lin et al, 2011) ou com metais (Wang et al, 2009Liu et al, 2011) podem não só diminuir o bandgap gerando resposta na região do visível, mas também melhorar a eficiência da separação elétron-buraco, favorecendo a atividade fotocatalítica (Liu et al, 2014).…”