Silver nanoparticles decorated anatase TiO 2 nanotubes for removal of pentachlorophenol from water

Abstract

a b s t r a c tOne-dimensional nanotubes are promising materials for environmental applications. In this study, anatase TiO 2 nanotubes (TNTs) were fabricated using an alkaline hydrothermal method at 130°C and then calcinated at 400°C for 2 h. Ag nanoparticles were photo-deposited onto the TNTs for enhanced photodegradation of pentachlorophenol (PCP) under simulated solar light. The samples were characterized using transmission electron microscopy, physical adsorption of nitrogen, X-ray diffraction, X-ray photoelectron spectroscopy and UV-Visible diffuse reflectance spectroscopic techniques. The as-synthesized TNTs showed tubular structures with the outer and inner diameter of 9-10 and 5-6 nm, respectively. The results showed that metallic Ag nanoparticles were uniformly dispersed on the TNTs surface, and Ag/TNTs exhibited significant visible-light absorption. After 180 min irradiation, about 99% PCP was removed by Ag/TNTs (5.4 at.%), compared to 54.3% by P25 and 59.4% by pure TNTs. This is attributed to the synergistic effects between Ag nanoparticles acting as traps to effectively capture the photo-generated electrons, and the localized surface plasmon resonance (LSPR) of Ag nanoparticles promoting the absorption of visible light. The intermediates during the PCP photodegradation were systematically analyzed, ruling out the existence of high toxic polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Ag/TNTs showed excellent stability even after five cycles.

Effects of pentachlorophenol on the detoxification system in white-rumped munia ( Lonchura striata )

“…PCP has accumulated in the environment, thereby causing a potential risk to animals and humans (Kondo et al, 2005;Maenpaa et al, 2004;Yu et al, 2015). Halogenated phenolic compounds, including PCP, can accumulate in the blood and fetal tissues of birds, fish, cetaceans, and other mammals (Kunisue and Tanabe, 2009;Montano et al, 2013), and has also been found in bird eggs (Berger et al, 2004;Brambilla et al, 2009;Maenpaa et al, 2004).…”

The fabrication of the antibacterial paste based on TiO2 nanotubes and Ag nanoparticles-loaded TiO2 nanotubes powders

“…Moreover, the film is coated on the substrate having amorphous structure that affected the intensity of the diffraction peaks of TNTs. In the XPS analysis results of the O1s in Ag/TNTs, there is a major peak at 531 eV with binding energy characterising for oxygen in TiO 2 and a smaller peak at 528 eV associated with characteristic for O ¡ [31]. The bonding of Ag into TNTs was investigated by the high-resolution XPS of the Ag 3d.…”

“…The results of the Ag3d XPS ( Figure 5(d)) have the following spotlight: first, the sample had more common smaller peaks inside the two top large spectra. After using Gaussian fit to analyse the XPS spectra of Ag 3d, there is appearance of peaks at 367.5, 368.6, 371.8, and 375 eV with binding energy positions corresponding to Ag + 3d 5/2 , Ag 0 3d 5/2 , Ag + 3d 3/2 and Ag 0 3d 3/2 , respectively [16,31]. This shows that there is an existence of two states of silver including Ag + and Ag 0 .…”

Advanced degradation of pentachlorophenol from water and process control using carbon nanofibers based composite electrodes

“…Pentachlorophenol (PCP) is a highly toxic persistent organic pollutant present in the environment due to its extensive use as a pesticide in agriculture and in wood preservation in industries. Its presence in water and soil could also contaminate the groundwater and become a potential risk to humans and animals [1].…”