Paweł Mazierski

Bio: Paweł Mazierski is an academic researcher from University of Gdańsk. The author has contributed to research in topics: Photocatalysis & Photodegradation. The author has an hindex of 16, co-authored 44 publications receiving 957 citations. Previous affiliations of Paweł Mazierski include Hokkaido University & Gdańsk University of Technology.

The role of lanthanides in TiO2-based photocatalysis: A review

Abstract: This review provides an in-depth analysis of lanthanide-titania-modified semiconductor photocatalysts (Er-, Ho-, Nd- and Tm-TiO2) for the photocatalytic degradation of organic pollutants under UV and visible light irradiation. In the first section, the unique properties of the lanthanides are summarized. In the second section, the influence of the preparation methods and surface properties of the selected rare earth metals (RE) on the photocatalytic activity of TiO2 was surveyed. In the third section, the mechanism of the RE-TiO2 visible light photoactivity was described. Finally, first-principles computer simulations of the RE-TiO2 structure and energy along with the influence of the anti-Stokes up-conversion process on the photocatalytic activity of the RE-TiO2 were discussed in detail.

Ordered TiO2 nanotubes: The effect of preparation parameters on the photocatalytic activity in air purification process

Abstract: Vertically ordered TiO 2 nanotube arrays were synthesized by anodic oxidation of titanium foil in glycerol, ethylene glycol and water-based electrolytes. The effect of electrolyte composition, anodization voltage, ultrasonic treatment and calcination time on the morphology of the resulting thin films, as well as on their photocatalytic activity in toluene removal, used as a model volatile organic compound, was investigated. Toluene, at the concentration of about 100 ppm, was irradiated over TiO 2 nanotube arrays using xenon lamp and light-emitting diodes (LEDs) in four subsequent cycles. The results showed that toluene could be mostly removed from the air after 30 min of irradiation over TiO 2 nanotubes (NTs), even using LEDs (375 nm) as a irradiation source. Photoactivity increased with increasing of nanotubes lengths and decreasing of crystallite size. Thus, TiO 2 nanotube arrays formed in ethylene glycol-based electrolyte by applying voltage of 40 V, followed by 1-h calcination at 450 °C, revealed the highest photoactivity and may be used several times without any significant decrease in activity.

Photocatalytic activity of nitrogen doped TiO2 nanotubes prepared by anodic oxidation: The effect of applied voltage, anodization time and amount of nitrogen dopant

Abstract: Nitrogen doped TiO 2 nanotube arrays were prepared by anodizing Ti foils in an organic electrolyte containing specified amounts of urea as nitrogen precursor. The photocatalytic activity of the samples was evaluated by analyzing the degradation kinetics of phenol in water. The influence of tubes’ length, tubes’ surface morphology and amount of nitrogen in the TiO 2 lattice on hydroxyl radical formation efficiency, photocatalytic activity and stability in four cycles was investigated. It was found that the photocatalytic activity as well as the charge carrier recombination rate depends on nitrogen concentration and the process parameters. 3.5 μm-long nanotubes containing 0.34 at.% of nitrogen seems to be favorable in phenol degradation and OH radicals generation under visible light. Comparison of XPS and photocatalytic activity test results shows decrease in phenol degradation efficiency with increasing amount of carbon contaminants on photocatalysts’ surface.

Enhanced photocatalytic properties of lanthanide-TiO2 nanotubes: An experimental and theoretical study

Abstract: A series of Er-, Yb-, Ho-, Tb-, Gd-, Pr-TiO 2 nanotubes (RE-NTs) was prepared via an electrochemical method. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis absorption, scanning electron microscopy (SEM) and luminescent spectroscopy. The experiments demonstrated that toluene in the gas phase was successfully degraded under visible light (LEDs λ max = 465 nm) using RE-NTs. In the presence of the most active sample (Ho-NTs), the photodegradation of toluene reached 30% after 60 min of vis irradiation. To investigate the localization of RE in the TiO 2 structure, computer simulations were performed using the plane-wave-based Vienna ab-initio simulation package (VASP) implementing spin-polarized density-functional theory (DFT) and the generalized gradient approximation (GGA). It is proposed that during the electrochemical process, TiO 2 systems with new Ho-f states below the conduction band of TiO 2 is formed. The photocatalytic activity under Vis irradiation is attributable not to OH but to other forms of reactive oxygen species (O 2 − , HO 2 , H 2 O 2 ).

Dual Cocatalysts in TiO 2 Photocatalysis.

Abstract: Semiconductor photocatalysis is recognized as a promising strategy to simultaneously address energy needs and environmental pollution. Titanium dioxide (TiO2 ) has been investigated for such applications due to its low cost, nontoxicity, and high chemical stability. However, pristine TiO2 still suffers from low utilization of visible light and high photogenerated-charge-carrier recombination rate. Recently, TiO2 photocatalysts modified by dual cocatalysts with different functions have attracted much attention due to the extended light absorption, enhanced reactant adsorption, and promoted charge-carrier-separation efficiency granted by various cocatalysts. Recent progress on the component and structural design of dual cocatalysts in TiO2 photocatalysts is summarized. Depending on their components, dual cocatalysts decorated on TiO2 photocatalysts can be divided into the following categories: bimetallic cocatalysts, metal-metal oxide/sulfide cocatalysts, metal-graphene cocatalysts, and metal oxide/sulfide-graphene cocatalysts. Depending on their architecture, they can be categorized into randomly deposited binary cocatalysts, facet-dependent selective-deposition binary cocatalysts, and core-shell structural binary cocatalysts. Concluding perspectives on the challenges and opportunities for the further exploration of dual cocatalyst-modified TiO2 photocatalysts are presented.

Single-Atom Catalysts across the Periodic Table.

Abstract: Isolated atoms featuring unique reactivity are at the heart of enzymatic and homogeneous catalysts. In contrast, although the concept has long existed, single-atom heterogeneous catalysts (SACs) have only recently gained prominence. Host materials have similar functions to ligands in homogeneous catalysts, determining the stability, local environment, and electronic properties of isolated atoms and thus providing a platform for tailoring heterogeneous catalysts for targeted applications. Within just a decade, we have witnessed many examples of SACs both disrupting diverse fields of heterogeneous catalysis with their distinctive reactivity and substantially enriching our understanding of molecular processes on surfaces. To date, the term SAC mostly refers to late transition metal-based systems, but numerous examples exist in which isolated atoms of other elements play key catalytic roles. This review provides a compositional encyclopedia of SACs, celebrating the 10th anniversary of the introduction of this term. By defining single-atom catalysis in the broadest sense, we explore the full elemental diversity, joining different areas across the whole periodic table, and discussing historical milestones and recent developments. In particular, we examine the coordination structures and associated properties accessed through distinct single-atom-host combinations and relate them to their main applications in thermo-, electro-, and photocatalysis, revealing trends in element-specific evolution, host design, and uses. Finally, we highlight frontiers in the field, including multimetallic SACs, atom proximity control, and possible applications for multistep and cascade reactions, identifying challenges, and propose directions for future development in this flourishing field.

Bio-Inspired Titanium Dioxide Materials with Special Wettability and Their Applications

Abstract: Their Applications Kesong Liu,†,∥ Moyuan Cao,† Akira Fujishima, and Lei Jiang*,†,‡ †Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191, PR China ‡Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China Research Institute for Science and Technology, Photocatalysis International Research Center, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan Institute for Superconducting and Electronic Materials, University of Wollongong, Innovation Campus, Squires Way, North Wollongong, NSW 2500, Australia