Effect of Pluronic P103 Concentration on the Simple Synthesis of Ag and Au Nanoparticles and Their Application in Anatase-TiO2 Decoration for Its Use in Photocatalysis

Abstract

Silver and gold nanoparticles were synthesized under environmentally-friendly reaction conditions by using a biodegradable copolymer and water as a solvent. The triblock copolymer Pluronic P103 was utilized as a stabilizing agent or soft template to produce Ag and Au nanoparticles (NPs) of different sizes. Moreover, in the synthesis of Au NPs, the polymer acted as a reducing agent, decreasing the number of reagents used and consequently the residues produced, hence, rendering the procedure less complicated. It was observed that as the concentration of the polymer increased, the size of the metallic NPs augmented as well. However, AgNPs and AuNPs prepared with 1 and 10 wt% Pluronic P103, respectively, showed a significant decrease in particle size due to the presence of polymeric soft templates. The hybrid materials (metal/polymer) were characterized by UV-Vis spectroscopy, DLS, and TEM. The pre-synthesized nanoparticles were employed to decorate anatase-TiO2, and the composites were characterized by DRS, XRD, BET surface area measurements, the TEM technique with the EDS spectrum, and XPS spectroscopy to demonstrate NPs superficial incorporation. Finally, methylene blue was used as a probe molecule to evidence the effect of NPs decoration in its photocatalytic degradation. The results showed that the presence of the NPs positively affected methylene blue degradation, achieving 96% and 97% removal by utilizing TAg0.1 and TAu10, respectively, in comparison to bare anatase-TiO2 (77%).

Upscaling of Electrospinning Technology and the Application of Functionalized PVDF-HFP@TiO2 Electrospun Nanofibers for the Rapid Photocatalytic Deactivation of Bacteria on Advanced Face Masks

“…The UV-vis absorption spectra measured for the MB solution prepared at 2 ppm before and after UV-A light irradiation for the respective untreated and functionalized electrospun membranes are shown in Figure 4a,b. In the absence of UV-A light, a decrease in the absorbance peak at 664 nm was observed for both the PVDF-HFP and PVDF-HFP @TiO 2 electrospun membranes, thus suggesting an adsorption capacity of the polymer-based electrospun membranes due to a high specific surface area [78,79]. With the occurrence of UV-A irradiation, the reduction in MB concentration was higher in presence of the PVDF-HFP @TiO 2 membrane than for PVDF-HFP.…”

“…because of the photo-induced formation of electron-hole pairs in the TiO2 NPs-embedded electrospun membrane [78,80,81]. Figure 4c shows that the MB degradation rate obtained for the PVDF-HFP electrospun membrane remained quite stable at around 20% after 5 h of UV-A light exposure, whereas a monotonous decrease occurred in the presence of the PVDF-HFP @TiO2 membrane with a dye degradation after 5 h of treatment equal to 51%.…”

“…With the occurrence of UV-A irradiation, the reduction in MB concentration was higher in presence of the PVDF-HFP @TiO 2 membrane than for PVDF-HFP. Moreover, the further shift of the peak down to low frequency (blueshift) clearly indicates that demethylation of MB occurs concurrently with the formation of radical species (such as hydroxyl •OH), because of the photo-induced formation of electron-hole pairs in the TiO 2 NPs-embedded electrospun membrane [78,80,81]. Figure 4c shows that the MB degradation rate obtained for the PVDF-HFP electrospun membrane remained quite stable at around 20% after 5 h of UV-A light exposure, whereas a monotonous decrease occurred in the presence of the PVDF-HFP @TiO 2 membrane with a dye degradation after 5 h of treatment equal to 51%.…”

Molecular and Nano-Structural Optimization of Nanoparticulate Mn2+-Hexarhenium Cluster Complexes for Optimal Balance of High T1- and T2-Weighted Contrast Ability with Low Hemoagglutination and Cytotoxicity

“…Moreover, high hydrophilicity of polyethylene oxide (PEO) blocks makes the so-called PEGylation of NPs promising surface decoration route, since it allows to gain in greater blood circulation time [ 33 ]. High hydrophilicity of some representatives of pluronics or triblock copolymers constituted from PEO and propylene oxide (PPO) blocks (exemplified by F-127) is also widely applied in colloid stabilization of composite NPs [ 34 , 35 , 36 ].…”