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

Abstract

The development of visible-light active titanium dioxide is one of the key challenges in photocatalysis that stimulates the development of TiO2-based composite materials and methods for their synthesis. Here, we report the use of pristine and Pt-modified dark titanium dioxide prepared via pulsed laser ablation in liquid (Nd:YAG laser, 1064 nm, 7 ns) for photocatalytic hydrogen evolution from alcohol aqueous solutions. The structure, textural, optical, photoelectrochemical, and electrochemical properties of the materials are studied by a complex of methods including X-ray diffraction, low-temperature nitrogen adsorption, electrophoretic light scattering, diffuse reflection spectroscopy, photoelectrochemical testing, and electrochemical impedance spectroscopy. Both the thermal treatment effect and the effect of modification with platinum on photocatalytic properties of dark titania materials are studied. Optimal compositions and experimental conditions are selected, and high photocatalytic efficiency of the samples in the hydrogen evolution reaction (apparent quantum yield of H2 up to 0.38) is demonstrated when irradiated with soft UV and blue LED, i.e., 375 and 410 nm. The positive effect of low platinum concentrations on the increase in the catalytic activity of dark titania is explained.

Understanding the pulsed laser‐induced modification processes of TiO2 nanomaterials in aqueous solution

“…11 Combined with the reducible properties of TiO 2 , 12 material-engineering techniques employing pulsed lasers are becoming more and more popular especially for the efficient preparation of TiO 2 -based functional materials with the control of defects and bulk phases. [13][14][15][16][17][18][19][20] This is based on the fact that the peak laser intensity can be controlled over a wide range by the use of pulsed lasers to result in the net energy input to vary from a mild heating [21][22][23][24] to a complete fragmentation. 25 Nanosecond laser pulses generally are known to cause thermal modification of the materials such as particle size, shape, phases, and defects.…”

Plasmonic Nanocomposites of ZnO-Ag Produced by Laser Ablation and Their Photocatalytic Destruction of Rhodamine, Tetracycline and Phenol

“…Several processes of photogenerated electron transfer are possible at the interface between ZnO and metallic Ag. At UV irradiation λ = 375 nm, electrons are transferred from the conduction zone of ZnO to Ag clusters with a formation of the Schottky barrier, which is characteristic of most noble metals with high yield work [54,55]. Since PLA-prepared ZnO NPs have many defects of different natures (for example, oxygen vacancies and interstitial zinc atoms in their ground and ionic states [46]), such defects can act as either electron acceptors or hole traps.…”

“…Schematically, the preparation of series of samples used in this study is presented in Figure 11. More details on material preparation and experimental setups, including the preparation of mixed colloids and ALT, can be found elsewhere [55,65].…”

t-BuOOH/TiO2 Photocatalytic System as a Convenient Peroxyl Radical Source at Room Temperature under Visible Light and Its Application for the CH-Peroxidation of Barbituric Acids

“…Titanium dioxide (TiO 2 ) is the most widely used heterogeneous photocatalyst due to its excellent chemical stability, low toxicity, moderate cost and availability [2]. The most profound applications of TiO 2 are currently solar cell design [3,4], the oxidative destruction of pollutants [1,[5][6][7], photodisinfection [8], hydrogen generation [9][10][11][12], CO 2 reduction [2,13] and water splitting [14]. One of the most important challenges for TiO 2 application in organic synthesis is to shift its activity form UV to visible light [15][16][17][18].…”