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At least 919 records · Page 51

Preparation of flower-like TiO{sub 2} sphere/reduced graphene oxide composites for photocatalytic degradation of organic pollutants

In this study, novel flower-like TiO{sub 2} sphere (FTS)/reduced graphene oxide (rGO) composites (FTS-G) were synthesized via a hydrothermal method. The photocatalytic performance of the FTS-G composites was evaluated through the photodegradation of rhodamine B (Rh B) and trichloroethylene (TCE) under simulated solar light irradiation. The rGO to FTS ratio in the composites significantly affected photocatalytic activity. The photocatalytic activities of FTS-Gs in the degradation of Rh B and TCE were superior to that of pure FTS. Of all the FTS-G composites tested, FTS-G with 1 wt% rGO (FTS-G-1) had the greatest photocatalytic activity, while FTS-G composites with rGO contents over 1 wt% had lower photocatalytic activities. Additionally, it is expected that the synthesis of FTS with a high specific surface area and well-developed pore structure and simultaneous conversion of GO to graphene-like rGO without the use of strong reducing agents could be a promising strategy to prepare other carbon-based flower-like TiO{sub 2} sphere composite photocatalysts. - Graphical abstract: Schematic illustration of high photocatalytic activity for FTS-G composites. Display Omitted.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Remarkable improvement of visible light photocatalytic activity of TiO{sub 2} nanotubes doped sequentially with noble metals for removing of organic and microbial pollutants

Highlights: • Ordered TiO{sub 2} nanotubes (NTs) were synthesized using anodic oxidation. • TiO{sub 2} NTs were modified with Ag and Au NPs that settled separately to widen visible absorption. • TiO{sub 2} NTs modified with Ag and Au NPs is superior visible light photocatalyst. • TiO{sub 2} NTs modified with Ag and Au NPs shows superior antibacterial activity. • Annealing temperature played important role in photocatalytic activity of TiO{sub 2} NTs. - Abstract: The aim of this study was to show that Ag and Au nanoparticles (NPs) can have a synergistic effect on the photocatalytic and antibacterial activity of TiO{sub 2} nanotubes (NTs) under visible irradiation. TiO{sub 2} NTs were grown on Ti substrate by anodic oxidation and modified with Ag and Au NPs by dip coating and sputtering methods, respectively. The spherical 5–20 nm Ag and Au NPs were deposited on TiO{sub 2} NTs with diameter of 50–80 nm. In contrast to obtained results under UV irradiation, visible-light absorption range and visible photocatalytic activity of Ag and Au co-modified TiO{sub 2} NTs were much higher than TiO{sub 2} NTs without modification and TiO{sub 2} NTs modified with monometallic NPs. Photocatalytic activity of modified TiO{sub 2} NTs increased with increasing annealing temperature and appearing rutile phase. Antibacterial activity of Ag and Au-comodified TiO{sub 2} NTs against E. coli was noticeably more than that of TiO{sub 2} NTs modified with monometallic NPs.

36 MATERIALS SCIENCE↗