Wojciech Macyk

Jagiellonian University | UJ · Faculty of Chemistry

Preparation of highly active core–shell/hybrid materials based on up-converting particles combined with semiconductors for photocatalytic application usually requires sophisticated and multi-step synthesis procedures. We propose a new design of a highly efficient NIR-driven photocatalytic system composed of spatially separated thin films of upconve...

Composites of semiconductors forming various heterojunctions have become more and more extensively explored in photocatalysis, but the heterojunction classification seems abstruse. This paper aims to present a strategy for correctly elucidating the heterojunction type. The following guidelines are proposed: (I) the determination of band alignment,...

A new two-step method for developing a nanocomposite of polypropylene (PP) decorated with photocatalytically active TiO2 nanoparticles (nTiO2) is proposed. This method involves low-temperature plasma functionalization of polypropylene followed by ultrasound-assisted anchoring of nTiO2. The nanoparticles, polymeric substrate, and resultant nanocompo...

Recent development in photocatalysis is increasingly focused on transforming organic compounds toward producing fine chemicals. Simple, non‐selective oxidation reactions (degradation of pollutants) and very demanding solar‐to‐chemical energy conversion processes (production of solar fuels) face severe economic limitations influenced by still low ef...

This work is a pioneering study demonstrating a promising breakthrough in water disinfection using a cobalt ferrite catalyst in a fixed bed. The performance of CoFe2O4 in E. coli inactivation is due to HO• radicals generated in the Fe3+/Fe2+ and Co3+/Co2+ redox cycles. In contrast to existing reports using cobalt ferrite nanoparticles, the bulk cob...

A lab-scale reactor with a fixed-bed hematite catalyst for the effective decomposition of H2O2 and bacteria inactivation was designed. The bactericidal effect is the largest at a low initial bacterial count of 2·10³ CFU/L, which is typical for natural surface waters. When using a 5 mM H2O2 solution and a residence time of 104 min, the reduction in...

The photocatalytic selective reduction of 3‐nitrophenol to 3‐aminophenol was studied in the presence of titanium dioxide in the form of various anatase and rutile compositions. The reaction progress is altered by various parameters, which can be classified as intrinsic (depending on the chemical, structural, and electronic features) and extrinsic (...

The conversion of CO2 into valuable solar fuels via photocatalysis is a promising strategy for addressing energy shortages and environmental crises. Here, novel In2O3@Co2VO4 hierarchical heterostructures are fabricated by in situ growing Co2VO4 nanorods onto In2O3 nanofibers. First‐principle calculations and X‐ray photoelectron spectroscopy (XPS) m...

The results of this work cover the influence of plasmonic (gold) and non-plasmonic (palladium) nanostructures on the photocatalytic activity and redox properties of titanium dioxide. Materials decorated with gold, palladium and both materials were examined using photoelectrochemical and spectroelectrochemical methods to establish the changes introd...

Polymeric carbon nitrides (PCN) are sustainable, tunable, non-toxic and chemically stable materials that represent highly promising heterogeneous photocatalysts for light-driven hydrogen peroxide production via selective reduction of dioxygen. However, most of the studies on photocatalytic H2O2 production using PCN-based photocatalysts reported so...

Polymeric carbon nitrides (PCN) are sustainable, tunable, non-toxic and chemically stable materials that represent highly promising heterogeneous photocatalysts for light-driven hydrogen peroxide production via selective reduction of dioxygen. However, most of the studies on photocatalytic H2O2 production using PCN-based photocatalysts reported so...

Nanorod-TiO2 electrodes were obtained by a hydrothermal method in the presence of different concentrations of sodium chloride. The addition of NaCl during the synthesis promoted the formation of thinner, well-crystallized nanorods growing along the [001] crystallographic direction, while still, the most intense reflection is related to (101). The o...

This work aimed to revise the mechanism of photocatalytic activity of the TiO2/Ag2O system in photocatalytic water splitting accompanied by methanol photoreforming. The transformation of Ag2O into silver nanoparticles (AgNPs) during photocatalytic water splitting/methanol photoreforming was monitored using XRD, XPS, SEM, UV-vis, and DRS techniques....

Solar-powered CO2 reduction is a promising approach for mitigating the energy crisis and environmental issues. However, its efficiency is hindered by challenges including difficult CO2 activation, rapid charge recombination, and...

In this work preparation of titanium dioxide polymorphs modified with metallic (Au, Ag) nanostructures of different sizes was presented. The photocatalytic activity of such materials along with their photoelectrochemical and...

Polymeric carbon nitrides (PCN) are sustainable, tunable, non-toxic and chemically stable materials that represent highly promising heterogeneous photocatalysts for light-driven hydrogen peroxide production via selective reduction of dioxygen. However, most of the studies on photocatalytic H2O2 production using PCN-based photocatalysts reported so...

Materials based on titanium(IV) oxide and four dihydroxyanthraquinones were synthesized using a simple impregnation method. The dyes (1,2- 1,4-, 1,5- and 1,8-dihydroxyanthraquinone) did not alter the physical properties of bare TiO2, but photosensitized it to visible light, up to 600 nm. The materials exhibit good photocatalytic activity in this sp...

Solar‐driven CO2 reduction shows promise in alleviating climate change and energy crises, but it suffers from difficult CO2 activation and rapid electron/hole recombination in current photocatalysts. Here we develop novel metal‐organic frameworks (MOFs)‐derived In2O3/ZnO tubular S‐scheme heterojunction photocatalyst for CO2 photoreduction. Resultin...

Fenton oxidation with heterogeneous hematite catalyst in a fixed bed reactor was investigated for water disinfection. The granulated hematite catalyst was prepared and tested to decompose H2O2, inactivate bacteria E. coli and degrade oxytetracycline. X-ray diffraction patterns confirmed the stability of the catalyst phase after sintering and after...

Photocatalysis is considered a promising technology to alleviate the pressure of environmental pollution and energy shortage. Among various photocatalysts, cadmium chalcogenide quantum dots (CdX QDs) stand out due to their excellent visible light absorption ability and efficient charge separation properties. This review presents the atomic and elec...

Understanding of the TiO2-assisted phototransformations observed for fundamentally important derivatives of Rhodamine B is expected to bring consistent and eventually comprehensive knowledge on behavior of this dye. The photocatalytic transformations of Rhodamine B in solution irradiated with visible light embrace an N-deethylation process eventual...

Developing a high‐performance photocatalyst is important for realizing efficient photocatalytic H2O2 generation. Herein, a novel step‐scheme (S‐scheme) heterojunction photocatalyst C3N4/PDA (CNP) comprised of ultrathin g‐C3N4 (U‐CN) and polydopamine (PDA) is constructed by in situ self‐polymerization. The optimal photocatalyst presents an excellent...

Electrocatalytic hydrogen evolution reaction (HER) in acidic solution using Co-based oxides is extremely difficult due to their instability. Herein, we report a hollow carbon sphere-supported Pt/CoOx (Pt/CoOx-HCS) electrocatalyst for active HER in 0.5 M H2SO4 solution. Microstructural and electrochemical evaluations confirm the dissolution of major...

Metal oxide-organic hybrid semiconductors exhibit specific properties depending not only on their composition but also on the synthesis procedure, and particularly on the functionalization method, determining the interaction between the two components. Surface adsorption is the most common way to prepare organic-modified metal oxides. Here a simple...

In this paper, we describe the role of anatase and rutile crystal phases on diphenyl sulphide (Ph2S) catalytic and photocatalytic oxidation. The highly selective and efficient synthesis of diphenyl sulfoxide (Ph2SO) and diphenyl sulfone (Ph2SO2) at titanium dioxide was demonstrated. Ph2S oxidation in the presence of hydrogen peroxide at anatase-TiO...

Graphdiyne is an emerging material widely used in photocatalysis. Its excellent physicochemical properties, such as nonuniform electron distribution, uniform pore distribution, excellent electron mobility, and high chemical stability, make it promising for solar fuel production. Given the rapid development of graphdiyne-based photocatalysts and the...

Polluted air containing particulate matter (PM) is a huge environmental problem in the city of Kraków, Poland. PM causes numerous negative health effects including infection of the respiration system and cardiovascular disorders. The development of autoimmune disorders can be facilitated by redox active transition metals due to the generation of re...

The study proposes two new TiO2 photocatalysts with excellent photocatalytic properties obtained by the reverse micelle (RM-TiO2) and low temperature (LT-TiO2) methods. The crystal structure and morphology of the obtained TiO2 samples were analyzed by X-ray diffraction, scanning electron microscopy and IR-spectroscopy. The chosen synthesis conditio...

A key component of the photocatalytic fuel cell (PFC) is a photoanode, typically based on highly stable semiconductor (e.g., TiO2) that is capable of effective photoelectrocatalytic oxidation of fuels. Notably, the photo(electro)catalytic activity of TiO2 materials can depend heavily on the microstructural morphology, so that tailored crystals with...

Solubility of transition metal compounds plays a significant role in adverse health effects because that is one of the most important factors of particulate matter bioavailability in the body. In this study, we focus on the chemical analysis of particulate matter (PM) collected at different locations in the area of Kraków, one of the most polluted...

The diffuse reflectance spectroelectrochemistry (SE-DRS) and reversed double-beam photoacoustic spectroscopy (RDB-PAS) provide unique, complementary information on the density of electronic states (DOS) in the vicinity of the conduction band bottom. The measurements are performed under quite different conditions, representing the solid/liquid and s...

We developed low-temperature (up to 200 °C) synthesis of TiO2 nanocomposites, which allows precise tuning of the anatase/rutile ratio. The materials were synthesized hydrothermally from strongly acidic solutions of Ti(III) precursors and hydrogen peroxide. Two series of materials (A and B series) have been synthesized; the A series is characterized...

Thermodynamics and kinetics of primary photophysical and photochemical processes govern the overall photoactivity of photocatalytic and photoelectrocatalytic systems. A proper determination of redox potentials, Fermi levels, quasi-Fermi levels, distribution of electronic states and surface traps, as well as lifetimes of photogenerated charge carrie...

We have synthesized and characterized a series of TiO2(B)/anatase photocatalysts in the form of nano-belts. Spectroelectrochemical measurements (SE-DRS) revealed the staggered-type of the band alignment for anatase and TiO2(B) composites, with higher potentials of band edges for anatase. The photoactivity of the materials and photocurrent generatio...

A visible light responsive heterojunction system composed of Fe2O3 nanorods (NF), reduced graphene oxide (rGO) and double oxide perovskites (LaSrFe2–nConO6, n = 1 (LSFC) and 0 (LSFF)) was rationally designed for an effective photoelectrochemical water splitting. The photoelectrodes were characterized in terms of structure, surface, physicochemical...

Titanosilicate ferrierite zeolite (FER) and its delaminated form (ITQ-6), with various Si/Ti molar ratios, were synthetized and tested as catalysts for diphenyl sulfide (Ph2S) and dimethyl sulfide (DMS) oxidation with H2O2. The zeolites were characterized with respect to their chemical composition (ICP-OES), structure (XRD, UV–vis DRS) and texture...

Herein, two-dimensional (2D) TiO2 mesoporous nanosheets with three to four C3N4 layers grown in situ are employed to design a core–shell 2D/2D van der Waals heterojunction (TiO2/C3N4). Edge-terminated zero-dimensional (0D) Ti3C2 MXene quantum dots (TCQD) are subsequently integrated in the C3N4 surface via electrostatic interactions. The constructed...

Hydrogen production by photocatalytic water splitting is one of the most promising sustainable routes to store solar energy in the form of chemical bonds. To obtain significant H2 evolution rates (HERs) a variety of defective TiO2 catalysts were synthesized by means of procedures generally requiring highly energy-consuming treatments, e.g. hydrogen...

The core-shell NaYb0.99F4:Tm0.01@NaYF4 upconverting particles (UCPs) with a high UV emission to apply in NIR-driven photocatalysis were synthesized. The influence of the Yb3+ doping concentration in NaYxF4:Yb0.99−xTm0.01 core particles, and the role of the NaYF4 shell on the upconversion emission intensity of the UCPs were studied. The absorption o...

Samples of TiO2 (P25) doped with zinc, tin, and vanadium, thermally treated at 550 °C for 6 h, were tested as catalysts and photocatalysts for the oxidation of diphenyl sulphide to diphenyl sulfoxide and sulfone, using hydrogen peroxide as an oxidation agent. Thermal treatment of pure TiO2 and its vanadium-doped forms resulted in a decrease of anat...

Interaction of amorphous and crystalline TiO2 ultrafine particles (2–6 nm) with rutin results in the formation of colored nanomaterials of an excellent dispersity and enhanced colloidal stability in aqueous media. The FTIR and Raman spectra confirmed attachment of the rutin ligand via vicinal hydroxyl groups in a catechol-like fashion. The binding...

Synthetic procedures, including doping, sintering and surface coating, can noticeably affect the physicochemical properties of semiconductors. Introduced changes very often translate into photocatalytic and photoelectrochemical activity alterations. However, in this work we have focused on more subtle treatments, which result in lack of changes obs...

In the energy storage context, metal ion batteries such as Li, Na, and K are governing the market. However, their activity significantly relied on anode materials. Mostly, the charging of these batteries occurs by produced electricity from environmentally hazardous processes [1]. In a totally different approach, light can be utilized to accelerate...

DFT/D+U and density functional based tight binding (DFTB) molecular modeling was used to investigate the role of the structural, electronic and optical properties of reduced graphene oxide surface (r-GO), hybridized with hydrated TiO₂ moieties of various size, ranging from small molecular Ti₂O₄ clusters into extende...

The goal of the work is to verify which properties of TiO2-based materials, influenced by small amounts of Fe, Co, Ga, Bi, W, Mo, V and Ni species used as modifiers, play the predominant role in changing the photoactivity of TiO2. Two groups of materials were studied: TiO2 synthesized in the presence of nanocrystalline metal oxide and dissolved met...

Photocatalytic coatings at polymers, showing a visible light induced photoactivity, can be synthesized using a low temperature oxygen plasma treatment of the polymer (PP) followed by deposition of TiO2 nanoparticles and their sensitization with organic ligands. The whole process consists of three major steps: surface activation involving its partia...

Tai­lored crys­tals of anatase TiO2 have been syn­the­sized us­ing a hy­drother­mal method with hy­dro­flu­o­ric acid and sodium flu­o­ride as cap­ping agents. Ti­ta­nium diox­ide in the form of sheets, tetrag­o­nal trun­cated bipyra­mids, cuboids and belts of­fer dif­fer­ent ex­posed facets: {001}, {001}/ { 101}, {001}/ { 100} and {100}, re­spec­t...

The nanostructured Zn-doped cobalt ferrites (Co1-xZnxFe2O4, where x ranges from 0.0 to 1.0 with the step of 0.1) were studied in order to elucidate the relation between their cationic distribution within the spinel sublattices and catalytic properties. The thermal transformation of the precursors (metal hydroxides) obtained through hydroxide co-pre...

BiFeO3 (BF) and LaFeO3 (LF) perovskites were synthesized using a microwave-assisted (MW) and sol-gel (SG) methods. XRD, XPS, TEM, UV-DRS techniques were applied to study physicochemical properties of perovskites. In addition, Incident Photon-to-Current Efficiency (IPCE) measurements, Linear Sweep Voltammetry (LSV) and impedance spectroscopy were us...

For the first time, photosensitization of selected alkaline titanates with surface charge transfer complexes has been proven. Activation of BaTiO3, SrTiO3 and CaTiO3 to visible as well as ultraviolet light has been achieved by impregnation with catechol, salicylic acid and 2,3-naphthalenediol. Simple modification of titanates with organic compounds...