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A fast microwave-assisted method was used to grow zinc oxide. The synthesis was carried out under three different pH conditions (8, 10 and 12) with the precipitation agent triethylamine. The obtained materials were comprehensively characterised using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), low-temperature N2 sorption (BET model), and analysis of electrokinetic potential and thermal stability (TGA). It was established that the pH value had a significant impact on the crystallinity, morphology and thermal stability of the final products. The primary purpose of this study was to use the synthesised materials in a process of photodegradation (in the UV light range) of the model organic pollutant – 4-chlorophenol (20 mg/dm3). The photo-oxidation tests showed that the obtained zinc oxide materials exhibit good photodegradation and mineralisation efficiency. Moreover, the kinetics of the photocatalytic degradation of 4-chlorophenol were determined based on the pseudo-first-order model, assuming the Langmuir–Hinshelwood mechanism.

The main goal of the study was the hydrothermal-assisted synthesis of TiO2-ZnO systems and their subsequent use in photoactive processes. Additionally, an important objective was to propose a method for synthesizing TiO2-ZnO systems enabling the control of crystallinity and morphology through epitaxial growth of ZnO nanowires. Based on the results of X-ray diffraction analysis, in the case of materials containing a small addition of ZnO (≥5 wt.%), no crystalline phase of wurtzite was observed, proving that a high amount of modified titanium dioxide can inhibit the crystallization of ZnO. The transmission electron microscopy (TEM) results confirmed the formation of ZnO nanowires for systems containing ≥ 5% ZnO. Moreover, for the synthesized systems, there were no significant changes in the band gap energy. One of the primary purposes of this study was to test the TiO2-ZnO system in the photodegradation process of 4-chlorophenol using low-power UV-LED lamps. The results of photo-oxidation studies showed that the obtained binary systems exhibit good photodegradation and mineralization efficiency. Additionally, it was also pointed out that the dye-sensitized solar cells can be a second application for the synthesized TiO2-ZnO binary systems.

A TiO2/ZnO oxide system was proposed as a support for the immobilization of laccase from Trametes versicolor (LTV). The obtained TiO2/ZnO/LTV biocatalytic system was then applied in the decolorization/degradation of C.I. Reactive Black 5 and C.I. Acid Green 25 dyes. The efficiency of immobilization was evaluated based on catalytic properties (Bradford method, oxidation reaction of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and physicochemical (spectroscopic, porous, electrokinetic) analysis. The immobilization process was carried out with high performance (99.4%). Immobilized laccase retained about 40% of its activity in the whole analyzed temperature range and after 10 reaction cycles. Immobilization efficiency was also indirectly confirmed by the presence of characteristic functional groups (–C–H and –C–O), nitrogen and carbon on the TiO2/ZnO/LTV biocatalytic surface, identified by spectroscopic analyses. The increase in the surface area to 126 m2/g, change of isoelectric point (2.0) and zeta potential ranges (from +12.0 to −20.0 mV) after the immobilization process were also observed. The results show that the designed biocatalytic system enables the removal of acid dyes (C.I. Reactive Black 5 and C.I. Acid Green 25) with high efficiency (99% and 70%, respectively). Mass spectroscopy analysis indicated possible degradation products formed by the cleavage of N=N and C–N bonds.

The main goal of the study was the hydrothermal-assisted synthesis of TiO2-ZnO systems and their subsequent use in photoactive processes. Additionally, an important objective was to propose a method for synthesizing TiO2-ZnO systems enabling the control of crystallinity and morphology through epitaxial growth of ZnO nanowires. Based on the results of X-ray diffraction analysis, in the case of materials containing a small addition of ZnO (≥5 wt.%), no crystalline phase of wurtzite was observed, proving that a high amount of modified titanium dioxide can inhibit the crystallization of ZnO. The transmission electron microscopy (TEM) results confirmed the formation of ZnO nanowires for systems containing ≥ 5% ZnO. Moreover, for the synthesized systems, there were no significant changes in the band gap energy. One of the primary purposes of this study was to test the TiO2-ZnO system in the photodegradation process of 4-chlorophenol using low-power UV-LED lamps. The results of photo-oxidation studies showed that the obtained binary systems exhibit good photodegradation and mineralization efficiency. Additionally, it was also pointed out that the dye-sensitized solar cells can be a second application for the synthesized TiO2-ZnO binary systems.

Chlorophyllin (which was used as sensitizer) was adsorbed onto a synthetic titania–silica oxide system, prepared via a sol–gel method. It was investigated how the adsorption process was affected by the initial concentration of chlorophyllin and the contact time of the solution. The physicochemical and structural properties of the inorganic support were comprehensively analyzed, including determination of the dispersive properties and morphology of the material (particle size distribution, SEM image), crystalline structure (XRD), chemical composition (EDS), parameters of the porous structure (low-temperature N2 sorption) and thermal stability (TGA/DTA). The effectiveness of chlorophyllin adsorption on TiO2–SiO2 was examined by Fourier transform infrared spectroscopy. The degree of coverage of the inorganic support with chlorophyllin was calculated from the Berendsen and de Golan equation based on BET and elemental analysis results. The kinetics of the adsorption of chlorophyllin onto the synthetic titania–silica oxide system were also determined. The experimental data correspond directly to a pseudo-second-order model. Moreover, the photocatalytic activity of selected TiO2–SiO2/chlorophyllin hybrids with respect to the decomposition of C.I. Basic Violet 10 dye was investigated. It was found that the titania–silica hybrids conjugated with chlorophyllin exhibited higher photocatalytic activity in the degradation of C.I. Basic Violet 10 than the pure TiO2–SiO2 material. Moreover, the kinetics of the photocatalytic degradation of selected organic compound was determined based on the Langmuir–Hinshelwood equation, assuming the pseudo-first-order reaction.

A TiO2–ZnO binary oxide system (with molar ratio TiO2:ZnO = 8:2) was synthesized by a hydrothermal method, assisted by calcination at temperatures of 500, 600 and 700 °C, using zinc citrate as the precursor of ZnO. The morphology (SEM, TEM), crystalline structure (XRD, Raman spectroscopy), diffuse reflectance spectra (DRS), chemical surface composition (EDXRF), porous structure parameters (low-temperature N2 sorption) and characteristic functional groups (FT-IR) of the TiO2–ZnO oxide materials were comprehensively analyzed. The novelty of this work is the observation of the coexistence of the crystalline structures of anatase and ZnTiO3 in TiO2–ZnO oxide materials. Moreover, it is shown that the obtained materials absorb visible radiation. The key stage of the study was the evaluation of the photocatalytic activity of the TiO2–ZnO binary oxide systems in the degradation of model organic pollutants: C.I. Basic Red 1, C.I. Basic Violet 10, C.I. Basic Blue 3 and 4-nitrophenol. For all synthesized materials, a high efficiency of degradation of the model organic impurities was demonstrated. The results show that the synthesized products may be materials of interest for use in the degradation of organic pollutants. Moreover, the kinetics of the photocatalytic degradation of selected organic compounds were determined based on the Langmuir–Hinshelwood equation, assuming a pseudo-first-order (PFO) reaction.

Praca zostala zrealizowana w ramach projektu badawczego Politechniki Poznanskiej nr 03/32/DSPB/0806.

Three different 3D fibrous-like NiO/Ni(OH)2/Ni‑carbonized spongin-based materials were prepared via a simple sorption–reduction method. Depending on the support used, the catalysts were composed of carbon, nickel oxide, nickel hydroxide and zero-valent nickel, with the surface content of the nickel-containing phase in the range 15.2–26.0 wt%. Catalytic studies showed promising activity in the oxidation of phenolic compounds in water and in the reduction of 4-nitrophenol. The oxidation efficiency depends on the substrate used and ranges from 80% for phenol at pH 2 to 99% for 4-chlorophenoxyacetic acid (4-CPA) and methylchlorophenoxypropionic acid (MCPP). In the reduction reaction, all catalysts exhibited superior activity, with rate constants in the range 0.648–1.022 min-1. The work also includes a detailed investigation of reusability and kinetic studies.

One of the directions of development in the textiles industry is the search for new technologies for producing modern multifunctional products. New solutions are sought to obtain materials that will protect humans against the harmful effects of the environment, including such factors as the activity of microorganisms and UV radiation. Products made of natural cellulose fibers are often used. In the case of this type of material, it is very important to perform appropriate pretreatment before subsequent technological processes. This treatment has the aim of removing impurities from the surface of the fibers, which results in the improvement of sorption properties and adhesion, leading directly to the better penetration of dyes and chemical modifiers into the structure of the materials. In this work, linen fabrics were subjected to a new, innovative treatment being a combination of bio-pretreatment using laccase from Cerrena unicolor and modification with CuO-SiO2 hybrid oxide microparticles by a dip-coating method. To compare the effect of alkaline or enzymatic pretreatment on the microstructure of the linen woven fabrics, SEM analysis was performed. The new textile products obtained after this combined process exhibit very good antimicrobial activity against Candida albicans, significant antibacterial activity against the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus, as well as very good UV protection properties (ultraviolet protection factor (UPF) &gt, 40). These innovative materials can be used especially for clothing or outdoor textiles for which resistance to microorganisms is required, as well as to protect people who are exposed to long-term, harmful effects of UV radiation.

TiO2-ZnO heterostructures with multifunctional photoactive properties were prepared using the two-stage microwave method. The presence of a binary crystalline system (anatase – wurtzite) was confirmed by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). The multifunctional character of the obtained photoactive materials was evaluated in two different processes – photocatalysis and photovoltaics. Photo-oxidation tests proved that the TiO2-ZnO heterostructures demonstrate high photocatalytic activity in phenol degradation. Furthermore, the prepared titania-based heterojunction systems were employed as precursors of the semiconducting layers in the DSSCs working electrodes. The photovoltaic parameters of the cells, assembled with electrodes post-treated with TiCl4 solution, have been tremendously improved by as much as forty-fold. Additionally, the scientific novelty of the work should be emphasized, resulting from the utilization of microwave-assisted synthetic strategy for the first time to prepare highly efficient photoactive materials with significant application potential in both photocatalysis and photovoltaics (DSSC cells).

The TiO2-Fe3O4 composite materials were fabricated via the hydrothermal-assisted technique. It was determined how the molar ratio of TiO2 to Fe3O4 influences the crystalline structure and morphology of the synthesized composite materials. The effect of the molar ratio of components on the antibacterial activity was also analyzed. On the basis of XRD patterns for the obtained titanium(IV) oxide-iron(II, III) oxide composites, the two separate crystalline forms&mdash, anatase and magnetite &mdash, were observed. Transmission electron microscopy revealed particles of cubic and tetragonal shape for TiO2 and spherical for Fe3O4. The results of low-temperature nitrogen sorption analysis indicated that an increase in the iron(II, III) oxide content leads to a decrease in the BET surface area. Moreover, the superparamagnetic properties of titanium(IV) oxide-iron(II, III) oxide composites should be noted. An important aim of the work was to determine the antibacterial activity of selected TiO2-Fe3O4 materials. For this purpose, two representative strains of bacteria, the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, were used. The titanium(IV) oxide-iron(II, III) oxide composites demonstrated a large zone of growth inhibition for both Gram-positive and Gram-negative bacteria. Moreover, it was found that the analyzed materials can be reused as antibacterial agents in three consecutive cycles with good results.

Hydrothermal crystallization was used to synthesize an advanced hybrid system containing titania and molybdenum disulfide (with a TiO2:MoS2 molar ratio of 1:1). The way in which the conditions of hydrothermal treatment (180 and 200 &deg, C) and thermal treatment (500 &deg, C) affect the physicochemical properties of the products was determined. A physicochemical analysis of the fabricated materials included the determination of the microstructure and morphology (scanning and transmission electron microscopy&mdash, SEM and TEM), crystalline structure (X-ray diffraction method&mdash, XRD), chemical surface composition (energy dispersive X-ray spectroscopy&mdash, EDS) and parameters of the porous structure (low-temperature N2 sorption), as well as the chemical surface concentration (X-ray photoelectron spectroscop&mdash, XPS). It is well known that lithium-ion batteries (LIBs) represent a renewable energy source and a type of energy storage device. The increased demand for energy means that new materials with higher energy and power densities continue to be the subject of investigation. The objective of this research was to obtain a new electrode (anode) component characterized by high work efficiency and good electrochemical properties. The synthesized TiO2-MoS2 material exhibited much better electrochemical stability than pure MoS2 (commercial), but with a specific capacity ca. 630 mAh/g at a current density of 100 mA/g.

In the efforts for the removal of hazardous materials from the environment biological processes are a valuable tool. Although much attention has been paid to the changes in bacteria at the omics level, another, physical-chemical perspective on the issue is essential, as little is known of microbial response to continuous exposition on harmful substances. This study provides in-depth characterization of the physical-chemical parameters of bacterial biomass after hydrocarbons exposure. To provide comparability of the harmful effects of chlorotoluenes and xylenes non-exposed and 12-months hydrocarbons exposed cells were analyzed, using the advanced spectrometric methods, inverse gas chromatography and low-temperature N2 sorption to evaluate acid-base as well as dispersive properties of the studied biomass. Presented results indicate P. fluorescens B01 cells strategy aimed at protecting the cell, thus lowering its’ biodegradation efficiency as a result of metabolic stress. The outcome of the study was that prolonged exposure to pollutants might reduce the bioavailability of hydrocarbons to bacteria cells, and consequently decrease the effectiveness of decontamination of polluted sites by indigenous microorganisms.

It is well known that removal of vanadium ions from the natural environment has become a great challenge in recent years. Due to this fact, the present study concerns the application of binary oxides such as TiO2-ZrO2 (molar ratio 9:1) and TiO2-ZnO (molar ratio 7:3) synthesized by the sol–gel method with calcination at 873 K (TZ1 sample) or by the hydrothermal method at 433 K (TZ2 and T7Zn3 samples), respectively. The fabricated adsorbents were subjected to the detailed physico-chemical analysis including: dispersive properties, morphology, crystalline and textural properties as well as chemical composition. The vanadium(V) ions adsorption on the binary oxides was optimized by the experimental conditions such as pH (2–10), adsorbent dose (0.01–0.1 g), vanadium concentration (10–500 mg/L), agitation time (1 min–24 h) and temperature (293–333 K). The pseudo-first-order (PFO), pseudo-second-order (PSO) and intraparticle diffusion (IPD) kinetic models as well as the Langmuir, Freundlich, Temkin and Dubinin-Raduskievich isotherm models were applied for the description of V(V) adsorption. The adsorption capacities were found to be 129.3 mg/g for TZ1, 170.8 mg/g for TZ2 and to 195.9 mg/g for T7Zn3. The endothermic and spontaneous character of V(V) adsorption on the binary oxides was confirmed by the values of thermodynamic parameters. The best fitting of kinetic experimental data to the pseudo-second-order model was obtained. The maximum desorption yield (%D) was achieved using the 1 mol/L NaOH solution (97.96%-T7Zn3, 75.81%-TZ2, 62.88%-TZ1). Applicability of the inorganic oxides in V(V) and Fe(III) removal from spent catalyst leaching solutions was proved.

A novel TiO 2-ZrO 2 hybrid oxide material enriched with lanthanum via in situ modification was successfully synthesized via a sol–gel process and applied in tetracycline (TC) removal. Lanthanum was introduced to increase the adhesion of organic compound to the TiO 2-ZrO 2 surface, which is beneficial for adsorption capacity and photocatalytic activity. Detailed physicochemical analysis of the hybrid oxide materials was carried out using analytical techniques including energy dispersive X-ray spectroscopy (EDX), Fourier infrared spectroscopy (FTIR), low-temperature N 2 adsorption (BET model) and X-ray photoelectron spectroscopy (XPS). A key aspect of the research was the determination of optimum conditions for tetracycline removal from model solutions by a comprehensive method that combines adsorption and photocatalytic degradation processes. The maximum Langmuir adsorption capacity of the TiO 2-ZrO 2/La system with respect to TC was calculated to be 69.44 mg/g. Additionally, photocatalytic tests showed that 35 mg of TiO 2-ZrO 2/La photocatalyst was able to remove TC from a 10 mg/L model solution in 120 min with 100% efficiency. Thus, it is a very promising material for the treatment of wastewaters containing tetracycline.

Herein, the series of {0 0 1} exposed anatase nanosheets from HF-assisted solvothermal growth synthesis were obtained. The two-dimensional TiO2 were characterized, including both bulk (XRD, DR-UV-Vis, Mott-Schottky) and surface characteristics (N2 sorption, XPS, SEM) with experimental results compiled with Density Functional Theory (DFT) calculations. The effect of alcohol amount and type was studied, demonstrating the crucial role of nucleation rate on the final material properties, which was connected with the possible ligand exchange between F- and ROH in the [TiF6]2- octahedra, leading to further TiO2 condensation through an ether elimination reaction. Highly active 2D nanoparticles were easily obtained for different reaction times when a moderate amount of n-butanol or n-hexanol was introduced to the synthesis. The photoactivity of 2D TiO2 with exposed {0 0 1} facet strongly depended on the photocatalytic available surface area with an increased amount of ortho–hydroxyphenol (catechol) formed as a by-product. Meanwhile, the rise of n-butanol or n-hexanol content during solvothermal reaction or changing it to ethanol allowed to form smaller and more crystalline anatase particles, but their activity was hindered. For these samples, the slow phenol disappearance and no catechol formation occurred due to (i) a lower amount of adsorbed fluorine, (ii) band position shifting towards lower values, and (iii) the surface presence of Ti3+, which prevented the generation of ∙OH radicals. It was also found that changing the nucleation rate by modifying the reaction environment influences the fluorine ions distribution, determining the final properties of 2D structure photocatalyst.

Novel ionic liquid-functionalized mesoporous silicas were synthesized using triblock copolymer Pluronic F127 as a template and I. (3-chloropropyl)trimethoxysilane, which then reacted with the appropriate pyridine derivatives (Q-pSZ series), or II. 1-[3-(trimethoxysilyl)propyl]-3- or −4-undecanoylpyridinium chloride, and 3- or 4-[1-(hydroxylimine)undecyl]-1-[3-(trimethoxysilyl)propyl]pyridinium chloride (SZ series), as a source of IL functional groups. The synthesized materials were characterized by FT-IR, Raman, SEM, XPS, low temperature N2 sorption, and IGC technique. The ability of the fabricated materials as adsorbents was investigated for the removal of Pb(II), Cd(II) and Zn(II) from aqueous solutions and compared with the nonmodified silica. Sorption optimization experiments were performed by changing the factors affecting the metals ions removal, such as pH, temperature, time, metals ions concentration. The optimum pH range for adsorption of Pb(II), Cd(II) and Zn(II) was found to be 4–6 and, the optimum contact time was found to be 15 min and 45 min, for the series materials “Q-pSZ” and “SZ”, respectively. The adsorption isotherms were obtained using concentrations of the metals ions ranging from 50 to 200 mg/L. The adsorption process followed pseudo-second-order reaction kinetics, as well as Langmuir and Freundlich adsorption isotherms. Q-pSZK3 possessed adsorption capacities of 202.3 mg/g for Pb(II), SZ-Ox3 148.6 mg/g for Cd(II) and SZ-Ox4 133 mg/g for Zn(II). This study revealed that the fabricated materials were promising adsorbents for removal especially Pb(II), Cd(II) and Zn(II) from aqueous solutions.

Binary oxide systems containing TiO2 and CuO were synthesized using hydrothermal treatment and shown to have enhanced antibacterial properties. A detailed investigation was made of the effect of the molar ratio of components (TiO2:CuO = 7:3, 5:5, 3:7, 1:9) on the physicochemical parameters and antibacterial activity. Analysis of morphology (SEM, TEM and HRTEM) confirmed the presence of spherical and sheet-shaped particles. On the XRD patterns for the binary oxide materials, two crystalline forms (anatase and monoclinic CuO) were observed. It was found that an increase in CuO content led to a decrease in the BET surface area of the TiO2-CuO binary oxide systems. The synthesized TiO2-CuO materials exhibited very good antibacterial activity against both Gram-positive (methicillin-resistant Staphylococcus aureus and Bacillus cereus) and Gram-negative (Salmonella Enteritidis and Pseudomonas aeruginosa) bacteria. The obtained results show that TiO2-CuO oxide materials may have applications in the biomedical and food industries.

A microwave method was used for the synthesis of TiO2-CuO oxide systems. A detailed investigation was made of the effect of the molar ratio of components (TiO2:CuO = 9:1, 7:3, 5:5, 3:7, 1:9) on the crystalline structure and morphology. Transmission electron microscopy (TEM) confirmed the presence of octahedral and rod-shaped titania particles and sheet copper(II) oxide particles; moreover, HRTEM analysis indicated the presence of a heterojunction between TiO2 and CuO. The synthesized materials were analyzed by X-ray diffraction (XRD) and Raman spectroscopy, and two crystalline forms (anatase and monoclinic CuO) were detected. The key element of the work was to determine the photocatalytic activity of the obtained binary oxide systems in the degradation of tetracycline. Photo-oxidation tests proved that the binary oxide materials (especially the (9)TiO2-(1)CuO and (7)TiO2-(3)CuO samples) demonstrate high photocatalytic activity in the decomposition of tetracycline (95% after 90 min irradiation) compared with the reference titania samples. Furthermore, a Z-scheme heterojunction photocatalytic process mechanism was proposed. Another important part of the work was the determination of tetracycline photodegradation products using the HPLC/MS technique.

TiO2-MoO3 composite systems were successfully prepared using a template-assisted microwave method at molar ratios TiO2:MoO3 = 8:2, 5:5 and 2:8. The synthesized material systems were comprehensively characterized, in terms of their crystalline structure (XRD and Raman spectroscopy), morphology (SEM, TEM and HRTEM analysis) and parameters of the porous structure (low-temperature N2 sorption). The materials exhibited highly crystalline phases: anatase and hexagonal molybdenum trioxide. Moreover, TEM analysis revealed hexagonal prism particles of MoO3 and nanocrystalline particles of TiO2. The proposed template-assisted microwave synthesis enabled the incorporation of TiO2 particles on the surface of hexagonal particles of MoO3, which resulted in a stable junction between titania and molybdenum trioxide. The values of BET surface area were 57, 29 and 11 m2/g for samples obtained at molar ratios TiO2:MoO3 = 8:2, 5:5 and 2:8 respectively. In electrochemical applications, titanium dioxide plays a crucial role as an intercalation intensifier, in which MoO3 is responsible for current conduction. Taking account of the potential electrochemical applications, the best system was obtained at the molar ratio TiO2:MoO3 = 5:5. The anode could maintain a capacity of 400 mAh/g at current densities in the range 100&ndash, 1000 mA/g at potential values ranging from 1.00 to 3.30 V vs. Li/Li+. X-ray photoelectron spectroscopy (XPS) confirmed the effective intercalation of lithium ions into the TiO2-MoO3 composite materials.

Keywords: titania, nanoparticles, surfactants, microwave method, photocatalysis, DSSC

Novel binary and ternary oxide photocatalysts based on titania, zirconia and silica were synthesized via a sol-gel method assisted by a calcination process. The effect of the molar ratio of components as well as the temperature of calcination on the physicochemical and photocatalytic properties of the final products was examined. Particle size distribution (NIBS), scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), Raman spectroscopy, low-temperature N2 sorption, and X-ray fluorescence (XRF) were employed to investigate the dispersion, morphology, crystalline and textural structure as well as the chemical composition of the photocatalysts. Additionally, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) were used to confirm the chemical surface concentration and the presence of characteristic surface groups of the synthesized materials. The key stage of the research involved evaluation of the photocatalytic behavior of the synthesized materials in the catalytic decomposition of Rhodamine B (RhB) dye. The photocatalytic studies focused on determination of the effect of the type and crystalline structure of the photocatalyst, the pH of the reaction system, and the irradiation time on the efficiency of degradation of RhB in the presence of the synthesized oxide materials.

Due to its exceptional textural, morphological and mechanical properties, mesostructured cellular foam (MCF) silica is a suitable support material for enzyme immobilization. However, the simple and efficient protocol of enzyme immobilization using MCF is often overlooked. Thus, in the presented study, we describe the synthesis, modification and characterization of mesostructured cellular foam silica for use in laccase immobilization. It has been established that the synthesized materials are characterized by high surface area equal to approx. 550 m2 g−1 and pores with diameters of approx. 20 nm, which makes them suitable for effective enzyme binding. Furthermore, immobilization of the laccase onto both, unmodified and Cu-modified MCF has been carried out, resulting in process yield of over 95% and 85%, respectively. Upon immobilization, irrespectively of the support used, laccase retained higher activity (over 80%) at a wider temperature (20–40 °C) and pH (4–7) range, as compared to the free enzyme, which exhibited such high activity only at pH 5 and 30 °C. In addition, the reusability of the laccase immobilized onto MCF + Cu material has also been improved as it still retained approx. 90% of its initial activity after 10 reaction cycles. Finally, the obtained biocatalytic systems have been applied for degradation of tetracycline from aqueous solutions resulting in 100% removal of the antibiotic by the MCF + Cu + lac system due to simultaneous adsorption and biocatalytic conversion.

A microwave method was used for the synthesis of TiO2-ZnO oxide systems. A detailed investigation was made of the effect of the molar ratio of components (TiO2:ZnO=9:1, 7:3, 5:5, 3:7, 1:9) on the crystalline structure and morphology. Based on the TEM pictures, confirmed the presence of octahedral and rod-shaped titania particles and sheet zinc oxide particles. Moreover, the synthesized materials were analyzed by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM), and two crystalline forms - anatase and wurtzite were detected. Based on the adsorption-desorption N2 isotherms confirmed mesoporous characters of the analyzed binary materials, also the parameters of the porous structure have been defined. The key element of the work was to determine the photocatalytic activity of the obtained TiO2-ZnO oxide systems in the degradation of phenol. Photo-oxidation tests proved that the binary oxide materials (especially the (9)TiO2-(1)ZnO and (7)TiO2-(3)ZnO samples) demonstrate high photocatalytic activity in the decomposition of phenol (95% after 80 min irradiation) compared with the reference titania sample. Furthermore, it was also pointed out that the dye-sensitized solar cells can be a second application for the synthesized TiO2-ZnO materials. The best photovoltaic parameters have been found in the case of the (9)TiO2-(1)ZnO material, which was characterized by an efficiency of 8.84%. The improvement effect is caused by introducing a material (ZnO) with a higher conductivity band into the TiO2-ZnO oxide system, additionally improving the transport of electrons inside the semiconductor layer.