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Abstract 4-Carboxybenzaldehyde (4-CBA), a major component of purified terephthalic acid wastewater, is toxic to living organisms and required to be removed before the discharge of treated wastewater in a natural water body. In this work, the adsorptive removal of 4-CBA was studied using bagasse fly ash (BFA), a waste product from the sugar industry. The adsorption capacity of BFA was compared with the commercially available adsorbent, granular activated carbon (GAC). A 4-factorial, 5-stage central composite design (CCD) was used to optimize 4-CBA removal and adsorption uptake by BFA using response surface methodology (RSM). The variables considered for the study were pH, adsorbent dose (m), initial concentration (Co) and time (t). At the optimum treatment conditions of pH = 4, m = 9 g/L, Co = 100 mg/L and t = 7.5 h, the removal efficiency and adsorption uptake of 4-CBA on BFA were found to be 79% and 9.9 mg/g, respectively. BET surface area of BFA was determined to be 284 m2/g. A kinetic study was performed using a first- and second pseudo-order model. The adsorption equilibrium data were fitted for various adsorption models. A positive value $$\Delta H^{0}$$ Δ H 0 indicates that the adsorption process is endothermic. This study indicated that BFA is a cost-effective adsorbent for the removal of 4-CBA with high adsorption capacity and fast kinetics. Graphical Abstract

Bisphenol A (BPA) is a toxic substance that is released into the environment mainly from paint, polymer, plastics and pharmaceutical industries. In this study, spinel Co3O4 consisting of Co2+/(Co3+)2O4 nanospheres with excellent specific surface properties were systematically synthesized via a simple hydrothermal approach preceded by calcination. The as-synthesized Co3O4 spinels were used for peroxymonosulfate (PMS) activation to reduce the bisphenol A (BPA). The effects of operating parameters including PMS dosage, initial pH, catalyst dosage, and co-existing ions were detected during the BPA degradation. It was observed that at neutral pH, the nano-Co3O4/PMS system effectively degrades the BPA (∼92%) with very low cobalt leaching and excellent recyclability. Control experiment analysis confirms the magnificent performance of the Co3O4/PMS system and the synergistic interaction between Co3O4 and PMS. Various characterization techniques were used to determine the thermal, textural and structural properties. A chemical quenching study confirmed that both hydroxyl radicals (•OH) and sulfate radicals (SO4•−) promotes BPA oxidation. The chloride (Cl-) ions and dihydrogen phosphate ions (H2PO4-) have little inhibition effect while adding humic acid (HA) and HCO3- inhibits the BPA oxidation. Separation techniques such as high-performance liquid chromatography (HPLC) coupled with mass spectroscopy (MS) were used to identify the oxidative by-products and the mineralization pathway of BPA reduction. First-order pseudo-kinetics were observed for BPA degradation. However, the power law model also fits nth-order kinetics models.

Nasl. z nasl. zaslona. Soavtorji: Praveen Kumar, Ritesh Patidar, Vimal Chandra Srivastava, Shang-Lien Lo, Urška Lavrenčič Štangar. Opis vira z dne 9. 5. 2023. Članek št. 110023. Bibliografija: str. 25-33. Abstract.

In this study, the catalytic activity of Cu-derived oxide catalysts in glycerol hydrogenolysis was investigated and the effect on the selectivity of 1,2-propanediol (1,2-PDO) with the different Cu/Al molar ratios was observed. The glycerol conversion/1,2-PDO selectivity was found to be dependent on the metallic sites and surface acidity of the Cu-based catalyst. The surface acidity and metallic sites of Cu nanoparticles were significantly improved with the increase of Cu/Al mole fraction in the catalyst. The efficiency of the Cu-derived oxide catalyst was attributed to the well-dispersed Cu and the presence of acidic sites. As expected, the Cu-based oxide catalyst (3CuAl) showed remarkable catalytic performance for 1,2-PDO synthesis with the highest turnover frequency (TOF) from the hydrogenolysis reaction. It is observed that the Cu-derived oxide catalyst is stable and efficient under strident reaction conditions in the presence of water and high temperature (aqueous glycerol solution (20 wt%), 210 °C, 40 bar). Moreover, the reaction conditions for glycerol hydrogenolysis in the presence of active 3CuAl were optimized to maximize the selectivity of 1,2-PDO with TOF. In addition, overcoming the limitation due to the external mass transfer resistance was investigated. The rate of glycerol consumption was subjected to kinetic analysis, which revealed a zero-order relationship on glycerol concentration, indicating that adsorbed glycerol was the most tightly bonded organic adsorbate. Further, the experimental reaction data was validated through the developed artificial neural network (ANN) model.

The effect of different water matrices on the photocatalytic degradation of dissolved pharmaceuticals was explored. The focus was on the degradation efficiencies in wastewater effluent from a bioreactor and water effluent from a central wastewater treatment plant and comparing the results with degradation in deionized H$_2$O. The compounds tested included: oxytetracycline, marbofloxacin, ibuprofen, diclofenac, phenytoin, ciprofloxacin, sulfamethoxazole. For the experiments performed in this study, a compact packed-bed photocatalytic reactor was used in which the hybrid TiO$_2$ photocatalyst (sol-gel/P25) was deposited on ∼3 mm glass beads. As expected, the reactions proceed more slowly in wastewater than in deionized water, yet it is shown that removal of the compounds from the water is still possible even when other organic molecules are present. Total organic carbon measurements have shown that complete mineralization takes place albeit at slower rates than the initial degradation of parent compounds. The results show that an acidic pH can increase the reaction rates and the adsorption on the photocatalyst surface. Analyses of the degradation intermediates were performed using tandem liquid chromatography triple-quadrupole mass spectrometry system. Additionally, X-ray absorption spectroscopy was applied to get insight into the local structure of the photocatalyst before and after use. Understanding the effects that different wastewater compositions have on photocatalytic reactions will help to refine the potential applications of the technology.

ZnO photocatalysts were synthesized via solvothermal method and a reduced experimental design (Box–Behnken) was applied to investigate the influence of four parameters (temperature, duration, composition of the reaction mixture) upon the photocatalytic activity and the crystal structure of ZnO. The four parameters were correlated with photocatalytic degradation of methyl orange and the ratio of two crystallographic facets ((002) and (100)) using a quadratic model. The quadratic model shows good fit for both responses. The optimization experimental results validated the models. The ratio of the crystal facets shows similar variation as the photocatalytic activity of the samples. The water content of the solvent is the primary factor, which predominantly influence both responses. An explanation was proposed for the effect of the parameters and how the ratio of (002) and (100) crystal facets is influenced and its relation to the photocatalytic activity. The present research laconically describes a case study for an original experimental work, in order to serve as guideline to deal with such complicated subjects as quantifying influence of synthesis parameters upon the catalytic activity of the obtained ZnO.

Soavtorji: Boštjan Žener, Marin Kovačić, Hrvoje Kušić, Iztok Arčon, Marjetka Levstek, Urška Lavrenčič Štangar. Bibliografija: str. 30-39. Abstract.

BiVO4 has attracted attention of researchers as one of the promising candidates for visible-light photocatalysis due to its suitable bandgap (≈2.4 eV) and appropriate band structure for the water oxidation. However, the high recombination rate of photo-generated electron-hole pairs as well as short diffusion of charge carries may lead to low photocatalytic efficiency of BiVO4. These limitations may be overcome employing various strategies, including a design of iso-type homojunction, i.e. a junction between two different crystal phases of the same semiconducting material. Such structure can effectively suppress the charge recombination process improving the photocatalytic activity. In this study an iso-type homojunction (monoclinic- tetragonal) BiVO4 material was synthesized and then modified employing photodeposition technique using different amounts of Ag nanoparticles. The as-prepared Ag-BiVO4 has been characterized using SEM, XRD, FTIR, BET, and UV-vis spectra. The impact of Ag nanoparticles on the photoelectrochemical activity of BiVO4 has been systematically evaluated. In addition, electrochemical impedance spectroscopy (EIS) has conducted for the semiconductor/electrolyte interface. The results revealed that the charge transfer resistance decreased under illumination for all as-prepared materials, and Ag-BiVO4 exhibited smaller charge transfer resistance compared to pristine iso-type homojunction BiVO4 material. The photocatalytic activity of as- prepared materials was examined by monitoring the degradation of ciprofloxacin (CIP) as a model organic contaminant under solar irradiation within different pH range (4 to 8) employing Ag-BiVO4 with different Ag content photo-deposited (1 to 15%) and concentration of H2O2 (5 to 30 times the concentration of CIP) and compared to that of pristine iso-type homojunction BiVO4.

To further improve photocatalytic degradation of ciprofloxacin (CIP) with iso-type homojunction bismuth vanadate, silver and iron nanoparticles were photodepostied on the surface of photocatalyst. To determine the best conditions and the best photocatalysts for CIP degradation Response surface methodology was used. For iron photodeposited photocatalyst 3 factors [pH (4, 6, 8), concentration of H2O2 in comparison to CIP concentration (5, 17, 5, 30) and mass ration m (FeCl3 x 6xH2O) /m (BiVO4) (5%, 27, 5%, 50%)] were used and for silver ones two factors [pH (4, 6, 8), and mass ration m (AgNO3) /m (BiVO4) (1%, 8%, 15%)] were used, and in both cases the response was degradation of CIP.

After synthesis of iso-type homojunction (monoclinic-tetragonal) BiVO4 material, this material was enhanced by photodeposition of silver and iron separately. The newly synthesized materials shown to enhance photocatalytic degradation of ciprofloxacin (CIP), antibiotic from the European commission's Watch list. These enhancements happened due to different effects. Photodepsotion of silver enhanced the degradation of CIP, due to the effects of silver lowering the recombination in the material. Iron compound served as a photo-Fenton reagent which activated the production of hydroxyl radicals from hydrogen peroxide in photocatalytic reaction with H2O2. The goal of this study was to get both enhancements (recombination decrease and photo- Fenton activation of H2O2) in one material for an increase in CIP degradation. For that purpose, we combined the synthesis methods for the best photocatalyst from our previous research to see whether we will get the above mentioned combination of effects. The new materials were categorized by XRD, DRS, and SEM. All the new materials showed better solar light photocatalytic performance in CIP degradation then pristine BiVO4.

Monoclinic bismuth vanadate is a n-type visible light photocatalyst. It has a suitable band gap for visible light absorption. Under visible light irradiation it can degrade most of (simple) organic dyes in a few hours. For degradation of complex molecules some type of modification (usually use of doping or composite construction) is required. Throughout enhancing via morphological change spherical isotype homojunction BiVO4 was synthesized with EDTA via precipitation method and calculation at 450 °C. That BiVO4 improved degradation of diclofenac for 2, 5 times compared to the monoclinic bismuth vanadate. To further improve the photocatalytic activity of the photocatalyst, silver and iron nanoparticles were photodeposited on its surface. Newly synthesized materials were analyzed with DRS, XRD, XPS, SEM, EDX and BET analysis. In this study, we explored the effect of this deposit on hydrogen peroxide activation in photocatalysis with hydrogen peroxide. To determine the best conditions and the best photocatalyst for ciprofloxacin (CIP) degradation response surface methodology was used. Two factors: pH (4, 6, 8) and concentration of H2O2 in comparison to CIP concentration (5, 17, 5, 30) were the same. Mass ration of precursor compound and pristine bismuth vanadate was used as a third variable [m (FeCl3 x 6xH2O) /m (BiVO4) (5%, 27, 5%, 50%)] for materials with iron, and ration [m (AgNO3) /m (BiVO4) (1%, 8%, 15%)] for materials with silver. Enhancement of photocatalytic degradation of materials with photodeposited iron can be explained with photo- Fenton reactions. For materials with silver enhancement in photocatalysis can be expanded via silver catalysed decomposition of hydrogen peroxide, a reaction which complete mechanism is not known. It is assumed that the decomposition is a reaction with a radical mechanism in which superoxide radicals play an important role.

The presence of antibiotics in the environment may threaten both humans and wildlife because of their resistance and chronic toxicity. Ciprofloxacin (CIP) is one of the antibiotics included in the European Commission's Watch list which should be concerned for removal from groundwaters. Among the various strategies, the solar driven photocatalytic process using semiconductors appears to be one of the effective methods to remove antibiotics from aqueous solutions. In this research, a series of Ag and Fe-modified BiVO4 materials were co-precipitation method followed by simultaneous photodeposition of different amounts of Ag and Fe on the surface of BiVO4. Different time of photodeposition and precursor mass ratio were used as variables. The as-prepared materials were characterized via XRD, SEM/EDX, AFM and XPS to get insight into their morphology, structure and surface properties, while DRS, PL and electrochemical tests were used to elucidate their semiconducting properties. Immobilized photocatalyst, in a form of three layers on glass plates obtained by employing spin-coating, were used for photodegradation of CIP under stimulated sunlight irradiation at neutral conditions and with the addition of oxidant (H2O2) in order to determine degradation mechanisms and influence of water matrix constituents, as well as to correlate degradation pathways with the changes in biodegradability and toxicity.

The presence of antibiotics in the environment may threaten both humans and wildlife because of their resistance and chronic toxicity. Ciprofloxacin (CIP) is one of the antibiotics included in the European Commission's Watch list which should be concerned for removal from groundwaters. Among the various strategies, the solar driven photocatalytic process using semiconducting materials seems to be one of the effective methods to remove antibiotics from aqueous solutions. In this research, a series of transition metal Fe- modified BiVO4 materials were synthesized employing photo-deposition technique using different amounts of iron. The asprepared materials were characterized via FTIR, XRD, SEM, UV-vis DRS and electrochemistry measurements. Photoelectrochemical properties of materials showed that photo-deposited iron (nano)particles are markedly beneficial for reducing e-/h+ recombination in synthetized isotype homojunction BiVO4. The photocatalytic activity of as-prepared materials was examined by monitoring the degradation of ciprofloxacin (CIP) as a model organic pollutant under solar irradiation within different pH range (4 to 8) employing Fe-BiVO4 with different fe content photodeposited (1 to 15%) and compared to that of pristine iso-type homojunction BiVO4.

Amoxicillin (AMX) and ciprofloxacin (CIP) were widely used in human and veterinary medicine. In recent years, AMX and CIP were detected in drinking water samples and wastewater effluents in european communities. This occurrence of trace amounts of antibiotics (i.e AMX, CIP) in various bodies of water may promote imbalance in the ecosystem and leads to further development of antibiotic resistant pathogens. Thus, alarming government decision bodies to include AMX and CIP in the second EU “watch list” of European Decision (2018/840/EU). One of the promising solutions to remove these substances is the application of advanced oxidation technologies, e.g. sustainable solarassisted TiO2 -based photocatalysis. In this study, commercial grade TiO2 (P25 Aeroxide), and α-Fe2O3 (hematite) were utilized to prepare two layered photocatalytic films on a glass substrate via spin coating technique. Configurations of the layered films are as follows: pure TiO2 , pure α-Fe2O3 , TiO2 layers covering α- Fe2O3 , α-Fe2O3 layer over TiO2 and physically mixed 50% (w/w) of TiO2/Fe2O3 composite. All of the photocatalytic films were characterized for their surface and semiconducting properties to get insight into their photoactivity under solar irradiation. The hypothesis is that photocatalytic layered films would be more efficient for photocatalytic degradation of AMX and CIP in natural pH under solar irradiation compared to benchmark TiO2-P25.

BiVO4 is considered to be a perspective photocatalyst due to its low band gap (2.34-2.90 eV). However, photocatalytic performance of pristine BiVO4 is limited due to high electronhole recombination rate and low electron mobility. Hence modifications are necessary to mitigate these drawbacks. In this work, several methods were employed to synthesize BiVO4. The photocatalysts were characterized using techniques such as BET, DRS, FTIR, SEM/EDX, XPS and XRD to inspect their structure, morphology, composition, surface and optical properties. In addition, photoelectrochemical performance of the new photocatalysts was investigated. Photostability of the photocatalysts was studied using chronoamperometric technique as well. To further asses the performance of as-prepared photocatalysts, their activity was examined for the treatment of diclofenac, one of the common contaminants of emerging concern.

Supported MnO2-based nanomaterials were fabricated on fluorine-doped tin oxide substrates using plasma enhanced-chemical vapor deposition (PE-CVD) between 100 °C and 400 °C, starting from a fluorinated Mn(II) diamine diketonate precursor. Growth experiments yielded β-MnO2 with a hierarchical morphology tuneable from dendritic structures to quasi-1D nanosystems as a function of growth temperature, whose variation also enabled a concomitant tailoring of the system fluorine content, and of the optical absorption and band gap. Preliminary photocatalytic tests were aimed at the investigation of photoinduced hydrophilic (PH) and solid phase photocatalytic (PC) performances of the present nanomaterials, as well as at the photodegradation of Plasmocorinth B azo-dye aqueous solutions. The obtained findings highlighted an attractive system photoactivity even under visible light, finely tailored by fluorine content, morphological organization and optical properties of the prepared nanostructures. The results indicate that the synthesized MnO2 nanosystems have potential applications as advanced smart materials for anti-fogging/self-cleaning end uses and water purification.

Reuse of photocatalyst and activity-loss in consecutive cycles presents a major hurdle in the environmental application. In this study, thermal and chemical treatments have been investigated as potentially viable methods for photocatalyst reactivation. A composite prepared from titania and iron- exchanged zeolite was used as photocatalyst for diclofenac (DCF) removal under simulated solar irradiation. DCF and total organic carbon (TOC) removal extents, biochemical and chemical oxygen demand were monitored in reuse cycles, for air-dried, and thermally and chemically reactivated photocatalyst. Thermal reactivation yielded higher DCF and TOC removal extents, while chemical reactivation slightly improved photocatalyst stability and biodegradability in reuse cycles.

In spite of their ubiquity in water environment and documented harmful behavior, most of pharmaceuticals are not being regulated by drinking water standards. However, during the recent prioritization in the field of water legislation the three pharmaceutical compounds ; 17b-estradiol, 17a-ethinylestradiol and diclofenac (DCF), are added to the "watch list" in order to gather monitoring data for the purpose of supporting future prioritization. DCF, widely used as analgesic, antiarthritic and anti- rheumatic non-steroidal anti-inflammatory drug, is frequently detected in drinking water sources and wastewater effluents due to limited removal by common municipal wastewater treatment plants. Such findings impose a need for changing the current practice in wastewater treatment, by the integration of advanced technologies to achieve satisfactory treated effluents. Accordingly, the study explores the potential of immobilized TiO2 ; -based composite photocatalyst for solar driven treatment of diclofenac (DCF). The hypothesis is that the solar photocatalytic treatment of water containing recalcitrant organic pollutants would be more efficient when composite materials arc applied instead of pure AEROXIDE TiO2 P25. In that purpose, we applied two composite type photocatalysts made of two semiconducting materials: TiO2 ; and tin sulfide (SnS2). The first composite material is made during immobilization by combining two commercial (nano) materials: AEROXIDE TiO2 P25 and SnS2 MKN- 900, while second composite is prepared using one-step synthesis by sol-gel method. Their effectiveness in DCF removal and degradation were compared with AEROXIDE TiO2 P25 as reference photocatalytic material. The set hypothesis was confirmed ; TiO2-SnS2 photocatalyst showed higher activity under solar irradiation than reference TiO2. The influence of process parameters on the effectiveness of applied solar driven photocatalytic process (solar/TiO2-SnS2/H2O2) was studied using response surface modeling. The dominant influence of pH on process effectiveness can be attributed to the role of DCF adsorption within degradation mechanism by solar/TiO2- SnS2/H2O2. The photocatalyst composition was found to be rather important for DCF degradation yield, as well as oxidant concentration.

Rješavanje problema onečišćenja voda jedno je od glavnih pitanja zaštite okoliša sa ciljem očuvanja zdravlja ljudi i ekosustava. U novije vrijeme, u otpadnim vodama i prirodnim prijemnicima identificirane su postojane kemijske tvari iz grupe farmaceutika, sredstva za zaštitu bilja te industrijskih kemikalija, koje imaju potencijalno negativan utjecaj na okoliš. Obzirom da se vrste i količine ovih onečišćivala u vodenom okolišu kontinuirano povećavaju, nameće se potreba za razvojem i primjenom učinkovitih naprednih tehnologija za obradu voda. Tehnologije obrade voda temeljene na naprednim oksidacijskim procesima (Advanced oxidation processes, AOPs) omogućavaju razgradnju postojanih organskih onečišćivala, prevodeći ih u biorazgradive spojeve ili mineralizirajućih ih do CO2 i H2O. U ovom radu je istraživana primjena fotokatalitičkih naprednih oksidacijskih procesa uz korištenje nanočestica za obradu vode koja sadrži diklofenak, nesteroidni protuupalni lijek, koji je kao jedan od prvih farmaceutika uključen na „Watch“ listu unutar Okvirne direktive o vodama (2013/39/EU). Glavna ograničenja fotokatalitičkih procesa uz nano-TiO2 su: (i) niska aktivnost pod sunčevim zračenjem, (ii) aglomeracija tijekom obrade i (iii) separacija nakon obrade. Stoga je u ovom radu istraživana primjena nanokompozitnog fotokatalizatora na bazi nano-TiO2 i željezom modificiranog sintetskog zeolita ZSM-5 tipa (FeZ) u imobiliziranom sloju uz simulirano sunčevo zračenje („solar“). Aktivnost pripremljenog nanokompozitnog fotokatalizatora procijenjena je usporedbom konverzije diklofenaka u sustavima solar/TiO2 i solar/TiO2-FeZ. Korištenjem dizajna eksperimenata u kombinaciji sa metodom odzivnih površina istraživan je utjecaj procesnih parametara na učinkovitost oba istraživana procesa.

Voda je jedan od osnovnih resursa nužnih za život, no unatoč svijesti o njezinoj važnosti, količine dostupne pitke vode kontinuirano se smanjuju kao posljedica onečišćenja. Industrijske i komunalne otpadne vode opterećene su različitim organskim i anorganskim onečišćivalima te se moraju obraditi prije ispuštanja u prirodne prijemnike sukladno zakonskoj regulativi (NN 80/13). Iako obrađene vode u pravilu zadovoljavaju zakonske propise, nakon obrade mogu zaostati male koncentracije različitih postojanih onečišćivala (farmaceutici, pesticidi, itd) koje predstavljaju opasnost za okoliš i ljudsko zdravlje. Farmaceutici podrazumijevaju široki spektar spojeva sa raznim djelovanjima, te su kao takvi prisutni svakodnevno u našem životu. Zbog velike upotrebe te neodgovornog odlaganja, farmaceutici dospijevaju u okoliš i prirodne vode. Glavni put ulaska humanih farmaceutika u vodeni okoliš je njihovo izlučivanje nakon primjene te unošenje u komunalne otpadne vode, pri čemu su se uređaji za obradu komunalnih otpadnih voda pokazali su se nedovoljno djelotvorni za uklanjanje velikog broja farmaceutika [1]. Diklofenak, nesteroidni protuupalni lijek, je jedan od prvih farmaceutika identificiranih u prirodnim vodama te se redovito nalazi u efluentima uređaja za obradu komunalnih voda. Stoga je uključen na „Watch“ listu unutar Okvirne direktive o vodama (2013/39/EU) kako bi se pratilo i ustanovilo njegovo potencijalno štetno djelovanje na ekosustav i ljudsko zdravlje. Sukladno tome, nameće se potreba za razvojem održivih i ekološki prihvatljivih metoda za uklanjanje farmaceutika i drugih onečišćivala koji zaostaju nakon obrade konvencionalnim metodama. U ovom radu istraživana je učinkovitost naprednog oksidacijskog procesa UV-A/TiO2 za uklanjanje diklofenaka iz vode. Glavne prednosti primjene TiO2 u fotokatalitičkoj obradi voda vežu se uz njegovu visoku aktivnosti i relativno nisku cijenu. Nasuprot tome, ograničenja procesa obrade su vezana uz uklanjanje nanočestica nakon te aglomeraciju tijekom obrade. Stoga je u ovom istraživanju korišten imobilizirani sloj fotokatalizatora nano-TiO2 [2] uz UV-A zračenje. Istraživana je učinkovitost same obrade u ovisnosti o procesnim parametrima pH, koncentracija oksidansa (H2O2) te debljini sloja fotokatalizatora uz pomoć dizajna eksperimenata u kombinaciji sa metodom odzivnih površina.

The pharmaceuticals are of particular concern due to their ubiquity in the aquatic environment and their health effects. Since primary and secondary wastewater treatment (WWT) technologies are not specifically designed to remove some of contaminants of emerging concern (CECs) and their metabolites, pharmaceuticals are detected in different environmental matrices worldwide ; in WWT plant effluents, surface, ground and drinking waters. The goal of the study was to evaluate capability of photo-assisted advanced oxidation processes (AOPs) for the removal of Diclofenac (DCF), a common non-steroidal anti-inflammatory drug and one of the most widely available drugs in the world that showed adverse effects in different organisms even at very low concentrations. For that purpose, UV-C/H2O2 and UV-A/TiO2 process were applied. The influence of key operating parameters of applied photo-AOPs (oxidant/catalyst concentration and operating pH) was investigated using the combination of full factorial experimental design with response surface methodology (RSM). The operating conditions yielding the highest mineralization/degradation rates for each applied photo-AOP were determined. The efficiency of both processes was compared in terms of treatment time required to achieve referent mineralization extents (10%, 20%, 30%, 40%, 50%, 75% and 90%), where the changes in biodegradability and toxicity were compared.

The list of priority substances in the field of water policy, i.e. the chemicals identified among those presenting a significant risk to or via the aquatic environment, is periodically amended ; current Directive 2013/39/EC included pharmaceutical Diclofenac (DCF) in the “watch” list. DCF is a common non-steroidal anti- inflammatory drug and one of the most widely available drugs in the world that showed adverse effects in different organisms even at very low concentrations. Due to the fact that conventional wastewater treatment systems do not efficiently remove DCF, advanced treatment technologies capable of its complete removal or destruction of its biological activity, need to be evaluated and eventually employed. The goal of the study was to evaluate capability of zeolite-assisted advanced oxidation processes (AOPs) for the removal of DCF. For that purpose, heterogeneous Fenton process employing Fe- exchanged ZSM5 zeolite (Fe-ZSM5/H2O2) is applied. The applied zeolite-based catalyst is characterized prior and after the treatment in order to scan possible changes in its composition and morphology using ICP/MS, SEM and FTIR. The influence of key operating parameters of applied Fe-ZSM5/H2O2 process (operating pH, oxidant and catalyst concentrations) was investigated using the combination of Box-Behnken experimental design with response surface methodology (RSM). Besides, the effectiveness of Fe-ZSM5/H2O2 was compared with its analogous process, Fe3+/NH4ZSM5/H2O2, in order to investigated removal/degradation mechanisms occurring within the applied system. The operating conditions yielding the highest mineralization degree, and highest stability regarding Fe leaching were determined. The kinetics of Fe-ZSM5/H2O2 process for removal of DCF at determined optimal conditions and its reuse capability were studied as well.

Approximately, 15% of the total textile colorant production is estimated to be lost during dyeing and processing of textile fibres. If left untreated, these wastewaters can represent a serious environmental threat. In the present paper a combination of photocatalytic and biological degradation of prepared textile wastewaters (simulation of real textile effluent) is presented. Samples have been monitored through the course of photocatalytic experiments: change in UV-VIS absorbance spectra and complete decolouration were achieved for all three tested dyed wastewaters; however, only partial COD removal was achieved with photocatalytic oxidation (PCOx) and photocatalytic ozonation (PCOz). Toxicity test (Vibrio fischeri) of untreated and pretreated (constructed wetland, CW) samples showed a decrease in toxicity values only for the red-dyed wastewater. Comparison of efficiency of PCOx and PCOz for decolouration and mineralization of three structurally different dyes (anthraquinone and two azo dyes) has been done. CW pretreatment caused faster decolouration and substantial COD removal in PCOx (up to 45%). Pretreatment also accelerated decolouration during PCOz, but it accelerated COD removal only in the case of red-dyed wastewater due to short irradiation times applied.

The urethanosil semi-solid type of electrolyte with incorporated redox species (I-, I3-) was found to be appropriate as an intermediate layer between the WO3 working electrode and the Pt counter-electrode in hybrid electrochromic devices. Urethanosils were prepared by the sol-gel route from single end-capped alkoxysilane precursors, which were synthesized using mono ether terminated oligoethyleneglycols and isocyanatopropyltriethoxysilane. In the sol-gel processing of the redox electrolyte, besides the urethanosil precursor tetraethoxysilane served as a network former, oxalic acid as a gelation promoter, various iodidesž iodine as a source of redox species and triethyleneglycol as a non-volatile solvent. Time-dependent IR ATR measurements were performed to follow solvolysis and condensation of the organically modified silica framework. To take advantage of the high ionic mobility, negligible volatility, low viscosity and large electrochemical window, an ionic liquid (EtPrIm+I-) was also considered as a co-solvent and simultaneously as a source of the iodide redox moiety.

Prisotnost farmacevtskih učinkovin v okolju povzroča vse večjo zaskrbljenost, saj se proizvodnja in poraba le-teh iz leta v leto povečuje. Posledično se povečuje tudi njihovo izločanje v okolje. Običajne metode čiščenja na čistilnih napravah pri odstranjevanju zdravilnih učinkovin niso uspešne, zato so se raziskave osredotočile na sklopitev biološkega in kemijskega čiščenja z naprednimi oksidacijskimi procesi, med katere uvrščamo tudi fotokatalitsko razgradnjo. V heterogeni fotokatalizi se je ZnO zaradi svojih edinstvenih fizikalnih in kemijskih lastnosti izkazal kot potencialno učinkovit fotokatalizator. Diplomsko delo obsega hidrotermalno sintezo nanodelcev ZnO, oplaščevanje le-teh s klastri niklja in nadaljnjo kalcinacijo, z namenom optimizacije ter primerjave fotokatalitskih učinkovitosti pripravljenih materialov pri razgradnji farmacevtskih učinkovin. Pripravljene fotokatalizatorje sem za potrditev uspešnosti sinteze karakterizirala z različnimi tehnikami. Preučevala sem fotokatalitsko razgradnjo petih modelnih farmacevtskih učinkovin, in sicer sulfametoksazola, fenitoina, naproksena, ibuprofena in diklofenaka, saj se le-ti v odpadnih vodah pojavljajo v relativno visokih količinah. Za primerjavo njihove obstojnosti z obstojnostjo hormonskih motilcev, ki v okolju prav tako vzbujajo skrb, sem raziskala tudi fotokatalitsko razgradnjo dobro poznanega hormonskega motilca − bisfenola A. Fotokataliza poteka le ob prisotnosti svetlobe, zato sem primerjala tudi razliko v učinkovitosti razgradnje, če kot vir svetlobe uporabim ultravijolično ali vidno svetlobo. Kot pričakovano se je za najbolj učinkovit fotokatalizator izkazal z nikljem oplaščen ZnO, saj oplaščevanje z nikljem zmanjša hitrost rekombinacije nabojev in poveča aktivnost. Dodatno kalciniranje le-tega pa zaradi povečanja velikosti delcev povzroči zmanjšanje aktivnosti. Fotokataliza ob prisotnosti ultravijolične svetlobe se je izkazala za veliko bolj učinkovito. The presence of pharmaceutical agents in the environment is a growing concern as their production and consumption increases year by year. As a result, their excretion into the environment is also increasing. Conventional purification methods in wastewater treatment plants are not successful in removing pharmaceuticals. Therefore, research is focused on combining biological and chemical treatment with advanced oxidation processes, which include photocatalytic decomposition. In heterogeneous photocatalysis, ZnO has been shown to be a potentially effective photocatalyst due to its unique physical and chemical properties. This work involves the hydrothermal synthesis of ZnO nanoparticles, their coating with nickel clusters, and subsequent calcination, to optimize and compare the photocatalytic efficiency of the prepared materials in the degradation of pharmaceuticals. To confirm the success of the synthesis, I characterized the prepared photocatalysts using various techniques. I investigated the photocatalytic degradation of five model pharmaceutical agents, namely sulfamethoxazole, phenytoin, naproxen, ibuprofen, and diclofenac, as they are present in relatively large amounts in wastewater. To compare their persistence with that of endocrine disruptors, which are also of environmental concern, I also studied the photocatalytic degradation of the well-known endocrine disruptor bisphenol A. Photocatalysis occurs only in the presence of light, so I also compared the difference in degradation efficiency when using ultraviolet or visible light as the light source. As expected, Ni-grafted ZnO proved to be the most efficient photocatalyst because nickel grafting decreases the rate of charge recombination and increases the activity. However, additional calcination of ZnO leads to a decrease in activity due to an increase in particle size. Photocatalysis has been shown to be much more efficient in the presence of ultraviolet light.

Industrializacija, prekomerna uporaba fosilnih goriv in naraščanje prebivalstva so le eni izmed mnogih krivcev, da se je v zadnjih desetletjih koncentracija CO2 v ozračju povečala do te mere, da se človeštvo že sooča z resnimi okoljskimi težavami. Z zajemanjem in uporabo ter pretvorbo CO2 ne bi le zmanjšali količino toplogrednega plina, temveč bi tudi pridobili dragocene kemikalije. Eden izmed načinov k zmanjševanju koncentracije CO2 v ozračju je njegova pretvorba v HCOOH, ki je ne le uporaben tekoči material za shranjevanje vodika, temveč tudi C1 gradnik za kemično industrijo. Cilj diplomske naloge je bil predlagati trajnostno pot hidrogenacije CO2 v metanojsko kislino s hidrazinom kot posrednim virom vodika ter sintetizirati in izbrati katalizator, ki bo visoko aktiven in selektiven pri tem. Kot najbolj aktiven se je izkazal z manganom oplaščen ZrO2, kalciniran pri 900 °C (Mn+ZrO2-m), s katerim so bile izvedene nadaljnje reakcije za optimizacijo pogojev. Industrialization, overuse of fossil fuels, and population growth are among the many culprits that have increased atmospheric CO2 concentrations so much in recent decades that humanity is already facing serious environmental problems. By capturing, using and converting CO2, we would not only reduce the amount of this greenhouse gas, but also gain valuable chemicals. One of the ways to reduce the concentration of CO2 in the atmosphere is to convert CO2 into HCOOH, which is not only an important liquid material for hydrogen storage but also a C1 building block for the chemical industry. The aim of this work was to propose a sustainable method for hydrogenation of CO2 to formic acid using hydrazine hydrate as an indirect hydrogen source, and to synthesize and select a catalyst that is highly active and selective in this process. Manganese modified ZrO2 calcined at 900 °C (Mn+ZrO2-m) proved to be the most active catalyst, with which further reactions were carried out to optimize the conditions.

Povečanje emisij CO2 in njegov škodljiv vpliv na podnebje in okolje nas spodbujajo k zmanjšanju globalnih koncentracij CO2. Med najprimernejše načine sodi hidrogenacija CO2 v metanol, ki služi kot energent in predhodnik za vrsto industrijskih procesov. Glavni cilj diplomskega dela je bil razvoj nove generacije stabilnega in selektivnega nanostrukturnega katalizatorja na osnovi CeO2 nosilca, na katerega je bila z metodo mokre impregnacije nanešena žlahtna kovina za sintezo metanola s hidrogenacijo CO2. Sintetizirali smo večfunkcijske mezoporozne katalizatorje z visoko specifično površino ter jim podrobno določili morfološke in površinske lastnosti z modernimi instrumentalnimi karakterizacijskimi tehnikami. Aktivnost in selektivnost sintetiziranih katalizatorjev pri reakciji hidrogenacije CO2 v metanol smo proučevali v cevnem pretočnem reaktorju pri tlaku 50 bar in temperaturah 200 – 260 °C s pretokom plinske faze 50 mL/min. Izmed proučevanih katalizatorjev se je v procesu katalitske hidrogenacije CO2 kot najaktivnejši izkazal CeO2-Pt, edini selektiven za sintezo metanola pa je bil CeO2-Pd katalizator. V območju proučevanih obratovalnih in reakcijskih pogojev je najvišja vrednost prostorsko-časovnega izkoristka v prisotnosti tega katalizatorja znašala 49,8 mg/gkath. Increasing CO2 emissions and their harmful effects on the climate and the environment encourage us to reduce global CO2 concentrations. One of the possibilities is CO2 hydrogenation to methanol. Methanol can serve as an energy source and a precursor for various industrial processes. The aim of this thesis was to develop a new generation of stable and selective nanostructured catalysts based on CeO2 supports, on which a noble metal was applied with wet impregnation method for the synthesis of methanol by CO2 hydrogenation. We synthesized multifunctional mesoporous catalysts with a high specific surface area and determined in detail their morphological and surface properties using modern instrumental characterization techniques. The activity and selectivity of the synthesized catalysts in the CO2 hydrogenation reaction to methanol were studied in a fixed bed reactor at a pressure of 50 bar and temperatures of 200 – 260 °C at gas flow rate of 50 mL/min. Among the studied catalysts, CeO2-Pt proved to be the most active in the process of catalytic hydrogenation of CO2. The only catalyst with selectivity for methanol synthesis was CeO2-Pd. In the range of studied operating and reaction conditions, the highest value of space-time yield in the presence of this catalyst was 49.8 mg/gcath.

Heterogena fotokataliza sodi med napredne oksidacijske postopke (NOP) za odstranjevanje težko razgradljivih organskih pa tudi nekaterih anorganskih snovi. Pri tej metodi se kot fotokatalizator uporablja polprevodnik, ki ga vstavimo v reaktor in izvedemo fotokatalitsko reakcijo z osvetljevanjem z UV ali vidno svetlobo. Za namene izvajanja fotokatalitskih reakcij se tako v laboratoriju kot v industriji uporabljajo različne vrste reaktorskih sistemov. Delimo jih na tri skupine glede na vrsto uporabljenega fotokatalizatorja (suspendiran/imobiliziran), vrsto sevanja (UV/VIS/sončna svetloba) in glede na lokacijo uporabljenega vira sevanja (potopljen/zunanji/razporejen). Pri eksperimentalnem delu diplomske naloge smo spremljali učinkovitost fotokatalitske razgradnje za izbrana organska onesnaževala. Uporabili smo raztopine organskega barvila plazmokorint B ter farmacevtikov ciprofloksacina in oksitetraciklina hidroklorida. Z metodami UV-VIS spektroskopije in HPLC smo spremljali, kolikšna je adsorpcija posameznega onesnaževala v temi ter določili fotokatalitsko učinkovitost TiO2. Ta je bil imobiliziran na steklene kroglice, ki so bile naložene v cev fotoreaktorske celice. Pri raztopini barvila smo z večkratno uporabo katalizatorja spremljali še stabilnost nanosa. S ponovitvami fotokatalize raztopine plazmokorinta B smo ugotovili, da se imobilizirani TiO2 tekom razkroja onesnaževala ne izpira, kar omogoča njegovo večkratno uporabo. Učinkovitost oz. uspešnost fotokatalitske razgradnje smo dokazovali z raztopino ciprofloksacina, katerega razgradnja je bila 95 %. Pri omenjenih raztopinah smo koncentracijo onesnaževal spremljali z UV-VIS spektroskopijo. V nadaljevanju smo preučevali še razgradnjo raztopine oksitetraciklin hidroklorida, pri čemer smo s HPLC meritvami zaznali nastanek intermediata, ki se je nato uspešno razgradil. Heterogeneous photocatalysis is one of the advanced oxidation processes (AOP) for the removal of poorly degradable organic as well as some inorganic substances. In the method, a semiconductor is used as a photocatalyst, which is inserted into the reactor, and the photocatalytic reaction is carried out by illumination with UV or visible light. Various types of reactor systems are used in both laboratory and industrial settings to perform photocatalytic reactions. The reactors are divided into three groups according to the type of photocatalyst used (suspended/immobilized), the type of radiation (UV/VIS/sunlight) and the location of the radiation source used (immersed/external/distributed). In the experimental part of the work, we investigated the efficiency of photocatalytic degradation for selected organic pollutants. Solutions of organic dye plasmocorinth B and pharmaceuticals ciprofloxacin and oxytetracycline hydrochloride were used. UV-VIS spectroscopy and HPLC methods were used to monitor the adsorption of each pollutant in the dark and to determine the photocatalytic efficiency of TiO2. This was immobilized on glass beads loaded into the tube of the photoreactor cell. In the case of the dye solution, the stability of the deposit was monitored by repeated use of the catalyst. In the case of repeated photocatalysis of plasmocorinth B solution, we found that the immobilized TiO2 is not washed off during the degradation of the pollutant, which allows its repeated use. The efficiency of photocatalytic degradation was demonstrated with a ciprofloxacin solution, which was 95% degraded. For these solutions, the contaminant concentration was monitored by UV-VIS spectroscopy. Then, the degradation of oxytetracycline hydrochloride solution was studied, and HPLC measurements showed the formation of an intermediate, which was then successfully degraded.

Namen diplomskega dela je bila sinteza kompozitov grafitnega ogljikovega nitrida (g-C3N4) in titanovega dioksida, ki bi lahko bili učinkoviti fotokatalizatorji za uporabo v heterogeni fotokatalizi. g-C3N4 sem sintetizirala s polimerizacijo prekurzorja diciandiamida pod različnimi pogoji, kompozite pa sem nato pripravila s homogenizacijo v ahatni terilnici v masnem razmerju 1:1 g-C3N4 in komercialnega TiO2. Pripravljene kompozite sem nato karakterizirala z različnimi površinsko občutljivimi tehnikami, kot so: dušikova fizisorpcija, fotoluminiscenca, rentgenska praškovna difrakcija, elektronska spektroskopija (UV-Vis difuzna refleksija), infrardeča spektroskopija. Opravila sem tudi test aktivnosti kompozitov pod vidno svetlobo s kumarinom. Cilj je tako bila primerjava lastnosti katalizatorjev, ki so bili pripravljeni z različno končno temperaturo pri sintezi g-C3N4. Kot najbolj aktiven katalizator se je izkazal g-C3N4 600/TiO2, pri katerem je bil g-C3N4 sintetiziran s končno temperaturo 600 °C, imel je tudi najvišjo specifično površino med kompoziti. Ugotovili smo, da se kompozitom z večanjem končne temperature pri sintezi g-C3N4 povečujeta urejenost strukture in specifična površina ter da so kompoziti aktivni v vidnem spektralnem področju. Homogenizacija TiO2 in g-C3N4 v masnem razmerju 1:1 zmanjša hitrost rekombinacije nabojev in poveča aktivnost. The purpose of this thesis was to synthesize composites of graphite carbon nitride (g-C3N4) and titanium dioxide, which could be effective photocatalysts for use in heterogeneous photocatalysis. g-C3N4 was synthesized by polymerization of the dicyandiamide precursor under different conditions, and the composites were then prepared by homogenization in an agate mortar in a 1:1 weight ratio of g-C3N4 and commercial TiO2. The prepared composites were then characterised by various surface-sensitive techniques, such as: nitrogen physisorption, photoluminescence, X-ray powder analysis, electron spectroscopy (UV-Vis diffuse reflection), infrared spectroscopy and I also tested the activity of composites under visible light with coumarin. The aim was thus to compare the properties of catalysts, which were prepared with different final temperatures in the synthesis of g-C3N4. The most active catalyst proved to be g-C3N4 600 / TiO2, which contained g-C3N4 synthesized with a final temperature of 600 °C, it also had the highest specific surface area among composites. We found that composites increase the order of structure and specific surface area with increasing final temperature during g-C3N4 synthesis, and that composites are active under visible light. Homogenization of TiO2 and g-C3N4 in a weight ratio of 1:1 reduces the rate of charge recombination and increases activity.

Fotovoltaične tehnologije postajajo, zaradi neizbežnega izčrpavanja neobnovljivih virov, s sposobnostjo direktne pretvorbe sončne svetlobe v električni tok vse bolj zanimive pri čistejšem in okolju prijaznejšem pridobivanju električne energije. Kot odgovor povpraševanju se raziskave na področju sončnih celic množijo, kar je povod v razvoj tretje generacije celic, v katero spadajo tudi elektrokemijske sončne celice. Te postajajo zaradi svoje preproste izdelave ter enostavnih in cenovno ugodnih komponent konkurenčne konvencionalnim silicijevim celicam. Z željo po izboljšanju delovanja elektrokemijskih celic sem se v svoji magistrski nalogi osredotočila na optimizacijo delovne elektrode. S hidrotermalno sintezo sem ob različnih vsebnostih dodanega NaOH sintetizirala mikrodelce TiO2, katere sem v nadaljevanju uporabila pri pripravi paste, primerne za elektrokemijske DSSC celice (ang. dye-sensitized solar cells). S spreminjanjem količin dodanih suhih komponent, kombinacij topil ter s prisotnostjo surfaktanta sem poizkusila pridobiti najprimernejšo pasto. Z vrstično elektronsko mikroskopijo sem analizirala površino nanosov ter s snemanjem presekov določila tudi njihovo debelino. Sestavila sem celice s pripravljenimi TiO2 pastami in rutenijevim barvilom ter s pomočjo sončnega simulatorja izmerila njihove tokovno-napetostne karakteristike, pri čemer me je najbolj zanimal izkoristek. Obenem pa sem preverila tudi vpliv uporabe različnih elektrolitov in barvil, ekstahiranih iz invazivnih rastlin, na uspešno pretvorbo energije v DSSC celicah. Najvišji pridobljeni izkoristek celice, pripravljene z optimizirano TiO2 pasto ter rutenijevim barvilom, je znašal 2,72 %, kar je dober približek celici s komercialno TiO2 pasto, katere izkoristek je znašal 2,80 %. V kombinaciji z barvili, ekstrahiranimi iz invazivnih rastlin, in dobljeno najučinkovitejšo pasto TiO2 sem pripravila DSSC celice in preverila njihovo delovanje. Za zelo obetavno barvilo se je izkazal ekstrakt kanadske zlate rozge z dobljenim izkoristkom celice 0,30 %. Prav tako pa se je kot primernejša pasta za vezavo organskih barvil izkazala pripravljena pasta TiO2 iz sintetiziranih mikrodelcev. Given the inevitable depletion of non-renewable energy sources, photovoltaics is becoming increasingly interesting because it can convert sunlight directly into electrical energy and the energy production is environmentally friendly. Research on solar cells is multiplying in response to mass demand, leading to the development of third-generation cells. These include dye-sensitized solar cells (DSSCs). Since they are easy to manufacture with affordable components, they are becoming competitive to conventional silicon cells. In my master's thesis, I focused on optimizing the working electrode with the aim of improving the functionality of DSSC cells. TiO2 microparticles were prepared by hydrothermal synthesis with different concentrations of added NaOH and then used to prepare a suitable paste for DSSC cells. I attempted to obtain the most effective TiO2 paste by varying the amount of dry components added, different combinations of solvents, and the addition of a surfactant. I used scanning electron microscopy to analyze the surface of the deposits and determined their thickness by recording cross sections. I measured the current-voltage characteristics of DSSC cells composed of the prepared TiO2 pastes and ruthenium dye using a solar simulator. I was mainly interested in the efficiency. At the same time, I also investigated the influence on successful energy conversion in DSSC cells by using different electrolytes and dyes, extracted from invasive plants. The solar cell made with optimized TiO2 paste and ruthenium dye had the highest efficiency of 2.72%. This is a good approximation to a cell made with commercial TiO2 paste, whose efficiency was 2.80%. Combining dyes extracted from invasive plants with the most effective TiO2 paste, I made DSSC cells and evaluated their efficiency. Canadian goldenrod extract proved to be the most promising dye with an efficiency of 0.30%. The TiO2 paste prepared from synthesized particles also proved to be better at binding organic dyes.

S povečevanjem količine farmacevtikov v odpadnih vodah so se pojavile skrbi zaradi vplivov na okolje. Ker se je klasično biološko čiščenje izkazalo kot neuspešno za njihovo odstranjevanje, so se raziskave osredotočile na sklopitev biološkega čiščenja z naprednimi oksidacijskimi metodami, med katere spada tudi fotokatalitska razgradnja. Eden od procesov, ki fotorazgradnjo spremlja, je adsorpcija. Z namenom boljšega vpogleda v fotodegradacijo sem se v svoji diplomi osredotočil na razumevanje procesa adsorpcije. Za adsorbata sem izbral fenitoin in oksitetraciklin, ki se v odpadnih vodah pogosto pojavljata v relativno visokih količinah in hkrati nista zelo raziskana. Kot fotokatalizator sem raziskoval nanodelce ZnO, ki kažejo obete zaradi primerne energije prepovedanega pasu in relativno majhne škodljivosti za okolje. Diplomsko delo obsega karakterizacijo ZnO, študij kinetike in termodinamike adsorpcije obeh farmacevtikov na ZnO ter računalniške simulacije elektronske gostote po površini molekul. Ugotovil sem, da so v suspenziji nanodelci prisotni v obliki poroznih 500 nm aglomeratov z nekoliko pozitivno nabito površino. Adsorpcija obeh farmacevtikov spada v fizisorpcijo, ki je verjetno osnovana na elektrostatskih interakcijah. Ugotovil sem, da je adsorpcija na površino aglomeratov zelo hiter proces, medtem ko je difuzija in adsorpcija v pore veliko počasnejša. Fenitoin se adsorbira le na površino aglomeratov, medtem ko oksitetraciklin lahko vstopa tudi v pore ZnO. With the increase in the amount of pharmaceuticals in wastewater, concerns have arisen about the impact on the environment. As traditional biological treatment proves unsuccessful for their removal, research has focused on combining biological treatment with advanced oxidation methods, including photocatalytic degradation. One of the processes that accompanies photodegradation is adsorption. To gain better insight into photodegradation, the research was focused on understanding the adsorption process. Phenytoin and oxytetracycline were chosen as adsorbates because they are found in relatively high amounts in wastewater and at the same time are not very well researched. ZnO nanoparticles were explored as photocatalyst as they are promising due to sufficient band gap energy and relatively low environmental toxicity. The work was based on the experiments on the characterization of ZnO, the study of the kinetics and thermodynamics of adsorption of both pharmaceuticals on ZnO, and computer simulations of the electron surface potential of molecules. It was found that the nanoparticles in suspension are in the form of porous 500 nm agglomerates with a slightly positively charged surface. The adsorption of the two pharmaceuticals belongs to physisorption, which is probably due to electrostatic interactions. It was found that adsorption on the surface of the agglomerates is a very fast process, while diffusion and adsorption into the pores are much slower. Phenytoin is adsorbed only on the surface of the agglomerates, while oxytetracycline can also penetrate into the pores of ZnO.

With the increasing focus on the use of lithium-ion (Li-ion) batteries in automotive applications, the need for simulating or mimicking the electrochemical and thermal performance of the battery is of great interest. In this master's thesis, the detailed description of electrochemistry and electrochemical modelling is presented, with the importance of many parameters used in electrochemical modelling along with investigating its sensitivity.\ In thesis, the general description and analysis of electrochemical models are done, where the evaluation is based on their ability to simulate a complex electrochemical behaviour inside the cell. The base of electrochemical modelling is open-source code named Dualfoil. It was carefully studied in order to understand electrochemical modelling and how it can be manipulated to achieve desired goals. Dualfoil, last updated in 2014, was used to evaluate the models' accuracy and assessment of which parameters or inputs are the most sensitive ones for a specific type of battery. \ The thesis aims to understand the detailed chemical structure and properties of Li-ion battery cell such as type of battery cell, active materials used for cathode and anode, battery housing, main or side reactions, etc. Aside from simulation work, various measurements were performed in order to characterize the commercially available battery cells chemically. \ Leta 1991 se je na področju baterij zgodila revolucija, Sony je predstavil prvo litij-ionsko baterijo, ki je dosegla neprimerljivo višjo kapaciteto v primerjavi s klasičnim svinčevim ali nikelj-metal hidridnim akumulatorjem. Po 30 letih je jasno, da je del prihodnosti cestnega prometa električni pogon, saj zagotavlja ničelni operativni ogljični odtis. Baterije so postale ključna komponenta prenosnih elektronskih naprav (pametni telefoni, tablični računalniki ipd.), medicinskih naprav (srčni spodbujevalniki, inzulinske črpalke ipd.), shranjevalnikov električne energije ("off-grid" sistemi) in prevoznih sredstev (e-avtomobili, e-tovornjaki, e-skiroji, e-kolesa ipd.). Razvoj novih ali izboljšanje že obstoječih baterij združuje znanstvenike različnih strok mikropogled na baterijo pojasnjuje kemija in fizika, medtem ko makropogled elekrotehnologija in strojništvo. Poleg baterij vir električne energije predstavljajo tudi gorivne celice in superkondenzatorji, ki šele v zadnjih letih pridobivajo veliko pozornosti s strani energetike za pridobivanje in shranjevanje električne energije. Da lahko baterije postanejo resnično aplikativne in uporabne v prevoznih sredstvih, je potrebno znati napovedati njihovo življenjsko dobo in uporabnost. Prav ena izmed nalog elektrokemijskega modeliranja litij-ionskih baterij je napoved življenjske dobe baterije glede na njeno kemijsko sestavo. \ Trenutno so baterije, natančneje sekundarne litij-ionske baterije, najpogostejši prenosni vir energije. Trend uporabe litij-ionskih ali litij-polimernih baterij v avtomobilski industriji je povzročil veliko zanimanja za razumevanje in izboljšanje tega alternativnega sistema. S simuliranjem elektrokemijskega in termičnega delovanja baterij je omogočen razvoj že obstoječih in novih baterij za dosege večje kapacitete, daljše življenjske dobe, manjše porabe, manjše upornosti itd. V predstavljeni magistrski nalogi je podroben opis elektrokemije in elektrokemijskega modeliranja litij-ionskih baterij, kjer evalvacija temelji na njihovi sposobnosti simuliranja kompleksnega elektrokemijskega obnašanja znotraj baterijske celice s fizikalno-kemijskimi enačbami. Komercialno dostopni elektrokemijski modeli običajno temeljijo na splošno dostopni kodi Dualfoil, predstavljeni leta 1995 cite{Doyle1993}. Na spletni stani enega izmed izumiteljev elektrokemijskega modela Johna Newmana je bila zadnja posodobitev kode izvedena v letu 2014. Uporabnik lahko kodo uporabi, preuči in manipulira za doseganje svojega cilja. \ textbf{Namen in zasnova magistrskega dela} Cilj dela je razumeti podrobno kemijsko strukturo, lastnosti in procese v litij-ionskih baterijah, s pridobljenim znanjem analizirati elektrokemijski model Dualfoil, preučiti številne parametre in njihov vpliv na elektrokemijsko modeliranje ter na podlagi osnovnega elektrokemijskega modela analizirati komercialne elektrokemijske modele. Za izboljšanje modelskih napovedi za baterijske procese je bil izveden eksperimentalni del, katerega namen je bil opraviti in oceniti težavnost meritev nekaterih ključnih parametrov za točnost modelov.\ Za dosego cilja magistrske naloge sem delo razdelila na tri glavnine. \ Prvi del naloge je namenjen natančnemu študiju elektrokemije v galvanskem členu in analizi komercialnih elektrokemijskih modelov. Sledi preučitev in primerjava osnovnega elektrokemijskega modela Dualfoil a komercialnimi modeli AVL FIREtextsuperscript{TM} M, Siemens STAR-CCM+ in Siemens Battery Design Studio. Vsi omenjeni komercialni modeli temeljijo na modelu Dualfoil in vsebujejo dodatne modifikacije in nadgradnje. \ Drugi del je namenjen identifikaciji najpomembnejših parametrov v elektrokemijskem modelu Dualfoil za modeliranje LCO (litij kobaltov oksid) baterije in LMO (litij manganov oksid) baterije. Na podlagi rezultatov sledi karakterizacija vplivnosti in občutljivosti parametrov na točnost modela oceni oziroma napove se ključne parametre pri staranju baterije. \ Zadnji del je namenjen določitvi merljivosti parametrov, potrebnih za elektrokemijsko modeliranje. Parametri so bili na podlagi študija literature razdeljeni v tri kategorije: merljivi, preračunljivi ali predvideni parametri. Nekaj merljivih parametrov smo poizkusili določiti tudi z analizo treh komercialnih baterijskih celic. Na vseh celicah je bila opravljena elektrokemijska analiza, medtem ko smo izbrali zgolj cilindrično baterijo za kemijsko karakterizacijo. \ textbf{Litij-ionska baterija} \ Baterija je naprava za shranjevanje elektrokemijske energije, saj shranjuje kemično energijo v aktivnih materialih in jo pretvori v električno z elektrokemijsko redoks reakcijo. Poznamo dve kvalifikaciji baterij, primarno in sekundarno. V primarni sistem baterij spadajo baterije, ki se jih lahko izprazni zgolj enkrat gre za ireverzibilni proces (npr. alkalne suhe baterije). Za sekundarne baterije so značilni reverzibilni procesi, v okviru katerih lahko z zunanjim virom ponovno napolnimo baterijo (npr. Li-ion baterije). Sekundarne baterije, ki imajo trdni elektrodi ter tekoč elektrolit, so sestavljene iz: begin{itemize} item negativne elektrode ali anode tu poteka spontana reakcija oksidacije, item pozitivne elektrode ali katode tu poteka spontana reakcija redukcije, item separatorja, ki fizično loči katodo od anode in s tem prepreči nastanek kratkega stika, item elektrolita, ki deluje kot medij za prenos naboja med anodo in katodo, item različnih dodatkov ali aditivov, ki so namenjeni za izboljšanje prenosa naboja, doseganje večje kapacitete, večje stabilnosti itd. end{itemize} Pri baterijah je izbira materialov in njena zasnova tesno povezana z namenom izpolnitve sistemske zmogljivosti baterije. Prav tako tudi različne standardizirane oblike baterije zahtevajo komponente, prilagodljive tem oblikam (cilindrična, ploščata, prizmatična in gumbna). \ Visokoenergetska baterijska celica je sestavljena iz debelejših materialov tako omogočijo shranjevanje več energije. Debele elektrode zmanjšajo hitrost pretvorbe elektrokemijske energije v električno energijo, na podlagi česar postanejo celice manj odzivne na dinamične obremenitve. Hkrati so te baterije primernejše za uporabo v sistemih BEV (baterijska električna vozila) in PHEV (priključna hibridna električna vozila), ker dosežejo velike kapacitete in imajo boljšo zmogljivost praznjenja. Celica z veliko močjo ima tanjše elektrode z večjo poroznostjo in s tem večjo hitrost pretvorbe energije, zaradi česar je celica odzivna na različne obremenitve kljub nižji energijski gostoti. Uporabljajo se v sistemih HEV (hibridna električna vozila) kot pomožni modeli za moč. \ textbf{Modeliranje baterij z uporabo matematičnih modelov} \ Z leti so raziskovalci razvili različne modele, s katerimi bi lahko napovedali zmogljivost in življenjsko dobo baterije. Večina modelov upošteva pri napovedovanju življenjske dobe zgolj porabo energije, ne pa tudi vzorca uporabe in obremenitve baterije. Baterijski modeli so zasnovani na različnih filozofijah napovedovanja obnašanja v baterijski celici cite{Jongerden2009}: begin{itemize} item elektrokemijski model, item model z električnim vezjem, item analitični model, ki temelji na teoriji Peukerta ali Rakhmatova, item kinetični baterijski model, item stohastični model, ki temelji na teoriji Chiasserinija, item stohastično-kinetični model. end{itemize} Elektrokemijski modeli temeljijo na podrobno opisanih kemijskih procesih znotraj baterijske celice in zahtevajo dobro poznavanje elektrokemije in kinetike v celici. Pionirsko delo na tem področju je bilo opravljeno s strani treh znanstvenikov (Doyle, Fuller in Newman), ki so razvili elektrokemijski model za litijeve in litij-ionske celice cite{Doyle1993, Fuller2006, Doyle1995}, teorijo makrohomogene porozne elektrode pa Newman cite{Newman75}. Njihov model je sestavljen iz šestih glavnih nelinearnih enačb, ki kot rezultat podajo datoteko z naslednjimi spremenljivkami: napetost in tok kot časovno funkcijo, potencial, koncentracijo soli, reakcijsko hitrost in gostoto toka kot funkcijo časa in položaja v celici cite{Albertus2007}. \ Newman-Doyle-Fuller ali Dualfoil model cite{Albertus2007} je zelo natančen, ampak tudi kompleksen, saj je potrebnih okoli 60 parametrov. Veliko teh parametrov, potrebnih za modeliranje je znanih le razvijalcem ali proizvajalcem baterij. Dualfoil spada med pseudo-dvo-dimenzionalne (P2D) elektrokemijske modele, saj model enodimenzionalno (x-os) predstavlja prenos mase in naboja v elektrodah in elektrolitu dvodimenzionalno (r-os in x-os) je opisana difuzija litija v elektrodah. \ V Dualfoil modelu je izvedenih veliko predpostavk za matematično poenostavitev elektrokemijskega obnašanja baterijske celice nekatere izmed teh so: begin{itemize} item med interkalacijo se elektrode ne povečajo (ang. textit{swelling}), item ni konvekcije med masnim transportom v elektrolitu, item elektrolit je razredčen, item enakomerna toplotna in tokovna porazdelitev, item prenos naboja je opisan z Butler-Volmerjevo enačbo, item transport iona znotraj elektrolita je opisan s teorijo koncentrirane raztopine, item elektroda je sestavljena iz monodisperznih sferičnih delcev. end{itemize} Zaradi kompleksnosti meritev je zgolj nekaj raziskav usmerjenih k pridobitvi vseh merljivih parametrov za elektrokemijski model. Med magistrsko nalogo je bilo ugotovljeno, da je večina uporabljenih parametrov v modelih, pridobljenih iz literature, predpostavljenih ali ocenjenih. Zato smo izbrali osnovne parametre za modeliranje zgolj iz študij, kjer so bili ti izmerjeni ali pa ocenjeni na podlagi eksperimentalnih podatkov. \ V nalogi smo se osredotočili predvsem na litij kobaltov oksid (LCO) in litij manganov oksid (LMO), čeprav se današnje litij-ionske tehnologije in avtomobilska industrija izogibajo uporabi kobalta. Razlog je v tem, da je bilo do sedaj največ raziskav in študij izvedenih na LCO ali LMO baterijah ter sta ti dve kemiji izbrani zaradi preverljivosti informacij. Današnje raziskave so usmerjene h katodni tehnologiji nikelj mangan kobalt (NMC) in k povečevanju kapacitete grafitne anode z dodatkom silicija ali silicijevega oksida, ki omogoča interkalacijo več litijevih ionov. Pri vseh omenjenih sistemih je še veliko tehnoloških težav in veliko parametrov ostaja nedoločljivih z eksperimentalnimi metodami.

Due to many advantageous physiochemical properties, titanium dioxide (TiO2) is the most widely used photocatalyst in numerous applications, such as wastewater treatment and air purification, self-cleaning surfaces and energy conversion (H2 generation). However, one of its disadvantages is the high electron-hole recombination rate, and coupling with other semiconductors is one of the strategies to improve it. The objective of this dissertation was to investigate how the photocatalytic activity of pure TiO2 can be improved by tin modification and to explain the mechanism of increased or hindered photoactivity in correlation with the structural properties of the modified TiO2 photocatalysts. A new low-temperature sol-gel synthesis route was developed to prepare Sn- or SnO2-modified TiO2 photocatalysts. In both cases, organic tin and titanium precursors were used. Tin in the form of Sn cations was used to prepare Sn-modified TiO2. In this case, the precursors went through the sol-gel reaction together to form a Sn-TiO2 sol. In the case of SnO2 modification, the SnO2 sol was prepared separately and additionally mixed with the TiO2 sol to form a TiO2/SnO2 bicomponent semiconductor system. Different molar ratios of tin to titanium were prepared to investigate the correlation between the tin concentration and the photocatalytic properties of the photocatalysts in the form of thin films. The results were used to optimize the synthesis conditions to obtain an improved activity of the modified TiO2 photocatalysts under UV-irradiation. The photocatalytic activity of the thin films was determined by measuring the degradation rate of an azo dye. An increase of up to 40 % in the photocatalytic activity of the dried samples (at 150 °C) was achieved when the TiO2 was modified with the Sn or SnO2 in a concentration range of 0.1 to 1 mol.%. At higher Sn or SnO2 loadings and after calcination of the samples at 500 °C, the photocatalytic activity of the photocatalyst was reduced compared to the unmodified TiO2. Different characterization techniques (UV-Vis, XRD, nitrogen physisorption, TEM, SEM and XAS) were employed to clarify the mechanism responsible for the enhanced and hindered photocatalytic performance of the Sn- and SnO2-modified TiO2 photocatalysts. The results showed that a nanocrystalline structure is already achieved in the samples by the low-temperature film treatment (drying at 150 °C) and that the photocatalytic efficiency is mainly influenced by the crystalline phase composition: anatase/rutile in the case of Sn-modified and TiO2/SnO2 in the case of SnO2-modified TiO2. The crystal size and specific surface area differ insignificantly between the equally thermally treated samples and partly explain the differences in photoefficiency of the calcined samples compared to the dried samples. The structural study at the atomic level, using the Sn K-edge EXAFS, revealed that Sn cations act as nucleation sites for the anatase to rutile transformation in the Sn-modified TiO2 photocatalysts, while in the SnO2-modified TiO2 samples the nanocrystalline cassiterite SnO2 is bound to the TiO2 nanocrystallites via the Sn-O-Ti bond. In both cases, the advantage of coupling the two semiconductors was achieved by separating the charge carriers and thus prolonging their lifetime for accessibility to participate in the redox reactions. The maximum activity enhancement was achieved in the low concentration range (0.1–1 mol.%), which means that an optimal ratio and contact of the two phases are obtained for the given physical parameters, such as particle size, shape and specific surface area of the catalyst.

Namen diplomskega dela je bil sintetizirati učinkovit katalizator na osnovi cerijevega dioksida z uporabo hidrotermalne metode. Katalitično delovanje sem nameravala preizkusiti pri sintezi propilen karbonata brez topil, z reakcijo cikloadicije propilen oksida in CO2, ki ga je v naravi v obilju in sodi med toplogredne pline. Zaradi pandemije Covid-19, načrtovanega laboratorijskega dela nisem mogla izvesti in sem zato diplomsko delo usmerila v teoretično obravnavo navedene teme. Analizirala sem nekaj že izvedenih in objavljenih okolju prijaznih sintez propilen karbonata. Primerjala sem različne katalizatorje in njihove lastnosti, ki so jih avtorji znanstvenih člankov določili z različnimi analitskimi tehnikami. The aim of this work was the synthesis of an effective catalyst based on cerium dioxide using the hydrothermal method. The catalytic activity would be tested in the synthesis of solvent-free propylene carbonate by the cycloaddition reaction of propylene oxide and CO2, which is abundant in nature and belongs to the greenhouse gases. Due to a pandemic Covid-19, I was not able to carry out the planned laboratory work, so I oriented my thesis on the theoretical treatment of this topic. Thus, I analyzed some already performed and published environmentally friendly syntheses of propylene carbonate. I compared different catalysts and their properties determined by the authors of the scientific articles using various analytical techniques.

Svetovno pomanjkanje vode predstavlja velik izziv sodobni družbi. Potencialen vir vode predstavlja ponovna uporaba odpadne vode, vendar jo moramo pred uporabo prečistiti. Ker so nekatera onesnažila zelo trdovratna, jih je nemogoče odstraniti s konvencionalnimi metodami, zato se je treba obrniti k naprednim oksidacijskim metodam. V tej diplomski nalogi sem raziskala eno izmed njih – polprevodniško fotokatalizo. Sintetizirala sem tri vrste raztopin z nanodelci TiO2 za nanos na milimetrske granule ter testirala njihovo fotokatalitsko aktivnost. Preizkusila sem proces žganja granul z nanosi. Testirala sem vpliv prepihovanja vzorca s kisikom na aktivnost fotokatalizatorja. The global water shortage is a challenge for modern society. Wastewater could be used as a potential source of water, but it must be properly treated before it can be used. Due to the persistence of some pollutants, advanced oxidation processes may be used in parallel with conventional water treatment processes. The aim of this work was to test one of the advanced oxidation processes - semiconductor photocatalysis. I synthesised three types of solutions with titania nanoparticles to coat millimetre-sized granules and test their photocatalytic activity. I also tested the process of thermal treatment of the granules with the coating. The influence of oxygen purging during the photocatalytic measurements was also tested.

Tekom diplomskega dela sem pripravila sol titanovega dioksida po anorganski sintezni poti iz TiCl4 z dodatkom NH4NO3 in hidroksipropil celuloze. Z dušikom dopirane fotokatalitsko aktivne tanke plasti sem pripravila tako, da sem nastali sol s tehniko potapljanja podlage nanesla na objektna stekla in jih nato termično obdelala pri temperaturi 600 °. Nastale plasti sem uporabila za fotokatalitsko razgradnjo antibiotika oksitetraciklina pod UV svetlobo z valovno dolžino 350 nm. Razgradnjo antibiotika sem spremljala spektrofotometrično na 15 minut celotni čas fotokatalitske razgradnje pa je bil 3 ure. Razgradnjo onesnažila v vodovodni in deionizirani vodi sem spremljala na osnovi meritev absorpcijskih spektrov učinkovine v območju med 200 in 800 nm. Opazovala sem vpliv pH raztopine in začetne koncentracije onesnažila na hitrost razgradnje. Naredila sem tudi umeritvene krivulje oksitetraciklina v deionizirani in vodovodni vodi, iz katerih lahko iz izmerjene absorbance pri valovni dolžini 355 nm (deionizirana voda) oziroma 375 nm (vodovodna voda) določamo koncentracijo oksitetraciklina v raztopini. Iz meritev absorbcijskih spektrov teh raztopin pred in po triurnem osvetljevanju z UV svetlobo sem lahko določila še spontano razgradnjo oksitetraciklina na UV svetlobi. During my diploma work, titanium dioxide sol was prepared by inorganic synthesis route from TiCl4 with addition of NH4NO3 and hydroxypropyl cellulose. The prepared sol was deposited onto object glasses by dip-coating technique. After thermal treatment at 600 °C nitrogen-doped photocatalytically active thin films were prepared. These layers were then used for the photocatalytic degradation of the antibiotic oxytetracycline under UV light irradiation with a wavelength of 350 nm. The antibiotic degradation was measured spectrophotometrically every 15 minutes the total time of photocatalytic degradation was 3 hours. The degradation of the contaminant in tap water and deionized water was monitored, based on the obtained absorption spectra of the active substance in the range between 200 and 800 nm. The influence of the pH of the solution and the initial concentration of the contaminant on the degradation rate was investigated. Calibration curves of oxytetracycline in deionized water and tap water were also constructed, from which the concentration of oxytetracycline in the solution can be determined from the measured absorbance at a wavelength of 355 nm (deionized water) and 375 nm (tap water). From the absorption spectra of these solutions before and after irradiation with UV light for three hours, the spontaneous degradation of oxytetracycline in UV light can also be followed.

Iz titanovega tetraklorida sem sintetizirala tridimenzionalne rožicam podobne mikrodelce TiO2, ki sem jih uporabila za pripravo treh različnih suspenzij. Suspenzije sem v različnem številu slojev nanesla na steklene ploščice in jih termično obdelala. Ploščice sem nato uporabila za fotokatalitsko razgradnjo barvila Plasmocorinth B v šaržnem reaktorju s svetlobo z valovanjem v območju ultravijoličnega spektra pri različnih pogojih. Fotokatalitsko razgradnjo barvila sem preverjala z merjenjem absorbance vzorcev s spektrofotometrom. Z vrstičnim elektronskim mikroskopom smo posneli ploščice z nanosi za podrobnejši vpogled v površino in strukturo nanosov suspenzije. Rezultati so pokazali, da se je za najboljše vezivno sredstvo izkazal polivinilpirolidon, saj je suspenzija s tem dodatkom v obliki plasti po termični obdelavi najhitreje razgrajevala barvilo. Razgradnjo barvila so dodatno pospešili trije nanosi suspenzije in prepihovanje vodne raztopine barvila s kisikom. Titanium tetrachloride was used as a precursor for the synthesis of three-dimensional flower-like TiO2 microparticles, from which three different suspensions were further prepared. The suspensions were deposited in a different number of layers to the glass slides, which were then heat-treated. The prepared plates were used for the photocatalytic degradation of Plasmocorinth B in a batch reactor under UV light and under different conditions. The photocatalytic degradation of the dye was checked by measuring the absorption of the samples with a spectrophotometer. A detailed insight into the morphology and structure of the photocatalyst was obtained with the scanning electron microscope. The results showed that polyvinylpyrrolidone proved to be the best binder as the resulting suspension in the form of layers and after heat treatment degrades the dye the fastest. The degradation of the dye was also accelerated by three layers of the suspension deposited on the glass slides and by purging the aqueous dye solution with oxygen.

Diplomsko delo sodi v širši problem pomanjkanja pitne vode, ki bo z naraščanjem prebivalstva in posledično vedno večjo porabo in osnaženostjo vode postal še večji. V delu je predstavljena rešitev čiščenja vode z uporabo fotokatalizatorja na osnovi bakrovega oksida. Veliko je že obstoječih načinov čiščenja vode, ampak zaradi edinstvenih lastnosti predstavlja bakrov oksid odlično alternativo že uveljavljenim katalizatorjem. V teoretičnem delu sem se osredotočil predvsem na to, kako fotokatalizator izboljšati, da dosega svoj maksimum. V eksperimentalnem delu je opisana priprava učinkovite imobilizacije bakrovega oksida na pelete aluminijevega oksida, ki služijo kot nosilec. Učinkovitost oksidacije sem preveril na organskem barvilu Plasmocorinth B. Opisana sta tudi reaktorja, ki sta bila uporabljena za koriščenje bakrovega oksida pri odstranjevanju tega onesnaževala v vodi. Nanostrukturo bakrovega oksida smo si podrobneje ogledali z vrstičnim elektronskim mikroskopom, ki je pokazal majhne delce in s tem veliko površino. Diploma thesis falls in the area of water shortage problem. This problem will only keep getting worse because of population growth. The solution to the problem can be CuO photocatalyst. There are many already existing processes for water purification, but copper oxide is an excellent alternative to the already established catalysts, because it provides some unique characteristics. In the theoretical part of the thesis, I focused on ways how to make a better photocatalyst and to achieve its maximum. The experimental part contains a description of efficient immobilization of CuO on aluminium oxide pellets. I tested the effect of photooxidation on organic dye Plasmacorinth B contaminant in aqueous solution. Description of both types of reactors used in testing are included. I examined copper oxide nanostructure with the help of scanning electron microscope. The image with high magnification showed small particles and large surface area.