Enhanced photocatalytic degradation of sulfamethoxazole by deposition of Au, Ag and Cu metallic nanoparticles on TiO₂

Abstract

Mono- (Au, Ag and Cu) and bi-metallic (Au-Ag and Au-Cu) nanoparticles were deposited on TiO and tested for the photocatalytic degradation of sulfamethoxazole using either UV-C or simulated sunlight. The optimal loading of metallic nanoparticles was determined as 1.5 wt% for Au and Ag, and 1.0 wt% for Cu. In the case of bi-metallic nanoparticles, only the ratio 1:0.5 wt% for both Au-Ag and Au-Cu was tested. In experiments using UV-C light, the highest degradation performance was found for Ag/TiO, while bi-metallic nanoparticles supported on TiO also showed increased photocatalytic activity compared with unmodified TiO. In simulated sunlight irradiation tests, Au/TiO showed to be the most efficient material. Complete mineralization of sulfamethoxazole was achieved when surface-modified materials were tested in both UV-C and simulated sunlight experiments. Photolysis was efficient to fully degrade sulfamethoxazole, although mineralization was lower than 10% for both luminic sources. The main by-products of sulfamethoxazole were determined in photolysis and photocatalysis tests using UV-C light, and degradation paths were proposed. By-products showed non-toxicity and low antibiotic activity. Reuse of the catalysts upon three reaction cycles did not result in the loss of activity.

Effect of Different Radiation Sources and Noble Metal Doped onto TiO2 for Contaminants of Emerging Concern Removal

“…Photolysis led to a reduction of about 50% of the initial concentration of each contaminant in 60 min (Figure 4). This is a similar result to that obtained by Zanella et al [33], who verified, using In the photocatalytic experiments, the photocatalysts were put in contact with the pollutants mixture for 10 min in dark conditions to test their adsorption capacity. SMX (Figure 4a) presented high adsorption capacity onto 0.5%Pd-TiO 2 with up to 70% of reduction.…”

Effects of crystallinity, {001}/{101} ratio, and Au decoration on the photocatalytic activity of anatase TiO2 crystals

“…The deposition-precipitation (DP) method [42] is a common approach used for decorating metal Au nanoparticles on TiO2 surfaces. In particular, in our work, 1.5 mL of 0.1 mol L -1 HAuCl4 solution was added to 1 g TiO2 (T700 and T800) in 20 mL containers.…”

Solar Photocatalytic Degradation of Sulfamethoxazole by TiO2 Modified with Noble Metals

“…SMX has already been used to test the efficiency of a sunlight mediated process with titanium dioxide modified for instance with tungsten (WO 3 /TiO 2 ) [29], copper (Cu/TiO 2 ) [30,31], gold (Au/TiO 2 ), and silver (Ag/TiO 2 ) [31]. For this purpose also non-TiO 2 based catalysts were investigated, such as flower-like bismuth oxide (Bi 2 O 3 ) [32], cuprous oxide-reduced graphene oxide (Cu 2 O/rGO) [33], composites of silver orthophosphate with tungsten oxide (Ag 3 PO 4 /WO 3 ), [34] and many others.…”