Highly Defective Dark Nano Titanium Dioxide: Preparation via Pulsed Laser Ablation and Application

Abstract

The development of methods to synthesize and study the properties of dark titania is of the utmost interest due to prospects for its use, primarily in photocatalysis when excited by visible light. In this work, the dark titania powder was prepared by pulsed laser ablation (Nd:YAG laser, 1064 nm, 7 ns) in water and dried in air. To study the changes occurring in the material, the thermal treatment was applied. The structure, composition, and properties of the obtained powders were studied using transmission electron microscopy, low-temperature N2 adsorption/desorption, X-ray diffraction, thermogravimetry/differential scanning calorimetry, X-ray photoelectron, Raman and UV-vis spectroscopies, and photoluminescence methods. The processes occurring in the initial material upon heating were studied. The electronic structure of the semiconductor materials was investigated, and the nature of the defects providing the visible light absorption was revealed. The photocatalytic and antibacterial activities of the materials obtained were also studied. Dark titania obtained via laser ablation in liquid was found to exhibit catalytic activity in the phenol photodegradation process under visible light (>420 nm) and showed antibacterial activity against Staphylococcus aureus and bacteriostatic effect towards Escherichia coli.

In situprobing of Pt/TiO2activity in low-temperature ammonia oxidation

“…The LAL method leads to the formation of the dispersed particles with a defective, distorted structure. [38][39][40][41] As the defects of the TiO2 support might stimulate the metal-support interaction, [42][43][44] the LAL can be a promising method for the preparation of the Pt/TiO2 catalysts active in the ammonia oxidation reaction. Previously, it was shown that the composites prepared by LAL are active in CO oxidation reaction, 38,39 low-temperature ammonia oxidation, 45 phenol photodegradation process under visible light.…”

“…Previously, it was shown that the composites prepared by LAL are active in CO oxidation reaction, 38,39 low-temperature ammonia oxidation, 45 phenol photodegradation process under visible light. 41 The supported Pt/TiO2 catalysts were studied using NAP-XPS and operando XAS -powerful complementary tools for the investigation of the catalysts under working conditions. The application of these methods provided insights into the evolution of the surface and bulk Pt particle structure under NH3+O2 conditions showing that the metal platinum particles do not undergo significant oxidation under the reaction conditions, regardless of the preparation method.…”

Laser-Based Synthesis of TiO2-Pt Photocatalysts for Hydrogen Generation

“…In Refs. [ 45 , 46 ], we obtained dark titania by nanosecond PLAL in distilled water. It features an intense absorption in the visible region of the spectrum caused by the presence of defects of various nature, and exhibits increased photocatalytic activity in the decomposition of the dye Rhodamine B and phenol, as well as an antibacterial effect against S. Aureus and E. Coli [ 45 ].…”

Biodegradable Polymer Nanosheets Incorporated with Zn-Containing Nanoparticles for Biomedical Applications

“…1), sulfides, carbides, etc. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. In this approach, laser beam is typically focused on a solid target, its pulses ablating the target and producing various nanostructures whose morphology, size and chemistry depend on the laser pulse parameters and liquid medium [14][15][16][18][19][20][21]25,29,30].…”

“…[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. In this approach, laser beam is typically focused on a solid target, its pulses ablating the target and producing various nanostructures whose morphology, size and chemistry depend on the laser pulse parameters and liquid medium [14][15][16][18][19][20][21]25,29,30]. As a preparative method, LAL is attractive for several reasons: (i) it is an easy-to-use and green technique consuming minimum chemicals; (ii) a wide variety of nanostructures can be prepared, with control over their composition and morphology; (iii) the method operates at nominally room temperature while can often generate unique phases and morphologies.…”