Low-Temperature Synthesis of Anatase TiO2 Nanoparticles with Tunable Surface Charges for Enhancing Photocatalytic Activity

Abstract

In this work, the positively or negatively charged anatase TiO2 nanoparticles were synthesized via a low temperature precipitation-peptization process (LTPPP) in the presence of poly(ethyleneimine) (PEI) and poly(sodium4- styrenesulfonate) (PSS). X-ray diffraction (XRD) pattern and high-resolution transmission electron microscope (HRTEM) confirmed the anatase crystalline phase. The charges of the prepared TiO2, PEI-TiO2 and PSS-TiO2 nanoparticles were investigated by zeta potentials. The results showed that the zeta potentials of PEI-TiO2 nanoparticles can be tuned from +39.47 mV to +95.46 mV, and that of PSS-TiO2 nanoparticles can be adjusted from −56.63 mV to −119.32 mV. In comparison with TiO2, PSS-TiO2 exhibited dramatic adsorption and degradation of dye molecules, while the PEI modified TiO2 nanoparticles showed lower photocatalytic activity. The photocatalytic performances of these charged nanoparticles were elucidated by the results of UV-vis diffuse reflectance spectra (DRS) and the photoluminescence (PL) spectra, which indicated that the PSS-TiO2 nanoparticles showed a lower recombination rate of electron-hole pairs than TiO2 and PEI-TiO2.

Photocatalytic degradation of dyes in water by analytical reagent grades ZnO, TiO<sub>2</sub> and SnO<sub>2</sub>: a comparative study

“…Lattice parameters were calculated for all three metal oxides by using XRD data and are listed in Table 1. The lattice parameters were consistent with reported values (Pawar et al, 2016;Cheng et al, 2011;Li et al, 2014Li et al, , 2013. Crystallite sizes were calculated using the intense peaks in XRD by the Debay-Sherrer formula; they were 103, 36, and 66 nm for ZnO, TiO 2 , and SnO 2 , respectively.…”

“…Recently, many semiconductors, such as SnO 2 , WO 3 , TiO 2 , CeO 2 , and ZnO, have been used in heterogeneous photocatalysis (Xu et al, 2013;Herrmann, 1999). Most of these semiconductors are wide-band-gap semiconductors, which require ultraviolet (UV) irradiation for photocatalysis (Lin and Lin, 2007;Abo et al, 2016). When a wide-band-gap photocatalyst is irradiated with light of energy equal to or higher than its band-gap energy, electron-hole pairs are created.…”

Branched polyethylenimine‐polyethylene glycol‐β‐cyclodextrin polymers for efficient removal of bisphenol A and copper from wastewater

“…It is worth mentioning that an increase of the thermal resistance of X-CD_3.9_0.78 occurred with regard to the b-PEI, PEG, and β-CD, which is typical of crosslinked polymers. 40 38 The glass transition temperature (T g ) of X-CD_3.9_0.78 was determined to be 3.84 C, which is higher than previously reported glass transition temperatures for a β-CD/PEG polymer.…”

Synthesis and Characterization of CuO, TiO2, and CuO-TiO2Mixed Oxide by a Modified Oxalate Route

“…Titanium oxide is found in three different crystalline forms: rutile, anatase, and brookite. The anatase phase has been reported to display higher photocatalytic activity than the others, owing to its higher density of localized states [31]. Different synthetic methods have been reported for the synthesis of anatase [31,32], rutile [33], and brookite [34] phases.…”

“…The anatase phase has been reported to display higher photocatalytic activity than the others, owing to its higher density of localized states [31]. Different synthetic methods have been reported for the synthesis of anatase [31,32], rutile [33], and brookite [34] phases. The precipitation of titanium by oxalate routes has been reported [35] with the precipitate formulated as TiO(C 2 O 4 )⋅ H 2 O which has as complex isomer Ti(OH) 2 (C 2 O 4 )⋅( − 1)H 2 O, with ≤ 3.5 (in solid state the product might be polymeric or amorphous).…”