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  • PozycjaOpen Access
    Magnetic moment centers in titanium dioxide photocatalysts loaded on reduced graphene oxide flakes
    (De Gruyter, 2021-01) Guskos, Nikos; Zolnierkiewicz, Grzegorz; Guskos, Aleksander; Aidinis, Konstantinos; Wanag, Agnieszka; Kusiak-Nejman, Ewelina; Narkiewicz, Urszula; Morawski, Antoni W.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    A whole series of titania nanocomposites modified with reduced graphene oxide (rGO) was prepared using solvothermal method followed by calcination. Modification of titania with rGO has been found to lead to better photocatalytic properties. The highest photocatalytic performance was obtained at calcination temperature of 600 degrees C. Electron paramagnetic resonance/ferromagnetic resonance measurements showed oxygen defects and ferromagnetic ordering systems. The linewidth of resonance line of oxygen defects decreased linearly with calcination temperature increasing up to 600 degrees C and an accompanying growth of mean crystallite size of anatase phase. The integrated resonance line intensity of oxygen defects depended on the calcination temperature and caused a very large increase in the intensity of resonance lines originating from oxygen defects, because inert atmosphere of calcination was enhanced by graphene presence. The occurrence of magnetic ordering system significantly influenced the performance of photocatalytic processes by changing the amount of oxygen defects.
  • PozycjaOpen Access
    Magnetic Resonance Studies of Hybrid Nanocomposites Containing Nanocrystalline TiO2 and Graphene-Related Materials
    (MDPI, 2022-03-18) Guskos, Nikos; Zolnierkiewicz, Grzegorz; Kusiak-Nejman, Ewelina; Guskos, Aleksander; Aidinis, Konstantinos; Bobrowska, Marta; Berczynski, Paweł; Wanag, Agnieszka; Pelech, Iwona; Narkiewicz, Urszula; Morawski, Antoni W.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    Nanocomposites based on nanocrystalline titania modified with graphene-related materials (reduced and oxidized form of graphene) showed the existence of magnetic agglomerates. All parameters of magnetic resonance spectra strongly depended on the materials’ modification processes. The reduction of graphene oxide significantly increased the number of magnetic moments, which caused crucial changes in the reorientation and relaxation processes. At room temperature, a wide resonance line dominated for all nanocomposites studied and in some cases, a narrow resonance line derived from the conduction electrons. Some nanocomposites (samples of titania modified with graphene oxide, prepared with the addition of water or butan-1-ol) showed a single domain magnetic (ferromagnetic) arrangement, and others (samples of titania modified with reduced graphene oxide) exhibited magnetic anisotropy. In addition, the spectra of EPR from free radicals were observed for all samples at the temperature of 4 K. The magnetic resonance imaging methods enable the capturing of even a small number of localized magnetic moments, which significantly affects the physicochemical properties of the materials.
  • PozycjaOpen Access
    New Insight on Carbon Dioxide-Mediated Hydrogen Production
    (Chemistry Europe, European Chemical Societies Publishing, 2022-04-03) Morawski, Antoni W.; Kusiak-Nejman, Ewelina; Pelech, Iwona; Cmielewska, Katarzyna; Sibera, Daniel; Staciwa, Piotr; Wanag, Agnieszka; Gano, Marcin; Ekiert, Ewa; Kapica-Kozar, Joanna; Witkowski, Kordian; Narkiewicz, Urszula; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    A new approach to hydrogen production from water is described. This simple method is based on carbon dioxide-mediated water decomposition under UV radiation. The water contained dissolved sodium hydroxide, and the solution was saturated with gaseous carbon dioxide. During saturation, the pH decreased from about 11.5 to 7-8. The formed bicarbonate and carbonate ions acted as scavengers for hydroxyl radicals, preventing the recombination of hydroxyl and hydrogen radicals and prioritizing hydrogen gas formation. In the presented method, not yet reported in the literature, hydrogen production is combined with carbon dioxide. For the best system with alkaline water (0.2 m NaOH) saturated with CO2 under UV-C, the hydrogen production amounted to 0.6 mu mol h(-1) during 24 h of radiation.
  • PozycjaOpen Access
    CO2 Sorbents Based on Spherical Carbon and Photoactive Metal Oxides: Insight into Adsorption Capacity, Selectivity and Regenerability
    (MDPI, 2022-10-11) Pelech, Iwona; Kusiak-Nejman, Ewelina; Staciwa, Piotr; Sibera, Daniel; Kapica-Kozar, Joanna; Wanag, Agnieszka; Latzke, Filip; Pawlowska, Karolina; Michalska, Adrianna; Narkiewicz, Urszula; Morawski, Antoni W.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    This work aimed to obtain hybrid composites based on photoactive metal oxide and carbon having adsorption properties. The materials, composed of titanium dioxide or zinc oxide and spherical carbon, were obtained from resorcinol-formaldehyde resin, treated in a solvothermal reactor heated with microwaves and then subjected to carbonization, were received. The functional groups of pure carbon spheres (unsaturated stretching C=C, stretching C-OH and C-H bending vibrations), CS/ZnO and CS/TiO2 samples were determined by FT-IR analysis. The characteristic bands for ZnO and TiO2 were observed below 1000 cm(-1). The thermal oxidative properties are similar for TiO2- and ZnO-modified carbon spheres. We have observed that the increased carbon sphere content in nanocomposites results in starting the decomposition process at a lower temperature, therefore, nanocomposites have a broader combustion temperature range. The effect of the oxides' addition to carbon spheres on their adsorption properties was evaluated in detail by examining CO2 adsorption from the gas phase. The selectivity of CO2 over N-2 at a temperature of 25 degrees C and pressure of 1 bar (a novelty in testing CS-based sorbents) calculated for 3.00 CS/TiO2 and 4.00 CS/ZnO was 15.09 and 16.95, respectively. These nanocomposites exhibit excellent cyclic stability checked over 10 consecutive adsorption-desorption cycles.
  • PozycjaOpen Access
    DC magnetization of titania supported on reduced graphene oxide flakes
    (De Gruyter, 2021-10-19) Guskos, Nikos; Zolnierkiewicz, Grzegorz; Guskos, Aleksander; Aidinis, Konstantinos; Glenis, Spiros; Wanag, Agnieszka; Kusiak-Nejman, Ewelina; Narkiewicz, Urszula; Morawski, Antoni W.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    DC magnetization of a series of titania nano-composites modified with reduced graphene oxide (rGO) has been investigated. Hysteresis loops observed at room temperature disappeared at low temperatures. At a temperature of about 100 K, a phase transition to the super-ferromagnetic order state was observed, probably due to the linear expansion and self-reorientation of the magnetic moments. Processes associated with magnetic moment reorientation can cause a hysteresis loop to disappear at low temperatures as well as superferromagnetic ordering. It was suggested that the isolated nanoparticle in the nanopore could be used to create a "compass" at a nanometer-sized level that would be many times more sensitive than the conventional one. Measurements of the zero-field cooling and field cooling modes do not exclude the possibility of the coexistence of a superparamagnetic state.
  • PozycjaOpen Access
    The Effect of the Modification of Carbon Spheres with ZnCl2 on the Adsorption Properties towards CO2
    (MDPI, 2022-02) Pelech, Iwona; Staciwa, Piotr; Sibera, Daniel; Kusiak-Nejman, Ewelina; Morawski, Antoni W.; Kapica-Kozar, Joanna; Narkiewicz, Urszula; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    Zinc chloride and potassium oxalate are often applied as activating agents for carbon materials. In this work, we present the preparation of ZnO/carbon spheres composites using resorcinol-formaldehyde resin as a carbon source in a solvothermal reactor heated with microwaves. Zinc chloride as a zinc oxide source and potassium oxalate as an activating agent were applied. The effect of their addition and preparation conditions on the adsorption properties towards carbon dioxide at 0 degrees C and 25 degrees C were investigated. Additionally, for all tested sorbents, the CO2 sorption tests at 40 degrees C, carried out utilizing a thermobalance, confirmed the trend of sorption capacity measured at 0 and 25 degrees C. Furthermore, the sample activated using potassium oxalate and modified using zinc chloride (a carbon-to-zinc ratio equal to 10:1) displayed not only a high CO2 adsorption capacity (2.69 mmol CO2/g at 40 degrees C) but also exhibited a stable performance during the consecutive multicycle adsorption-desorption process.
  • PozycjaOpen Access
    CO2 Reduction to Valuable Chemicals on TiO2-Carbon Photocatalysts Deposited on Silica Cloth
    (MDPI, 2021-12-28) Morawski, Antoni W.; Cmielewska, Katarzyna; Witkowski, Kordian; Kusiak-Nejman, Ewelina; Pelech, Iwona; Staciwa, Piotr; Ekiert, Ewa; Sibera, Daniel; Wanag, Agnieszka; Gano, Marcin; Narkiewicz, Urszula; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    A new photocatalyst for CO2 reduction has been presented. The photocatalyst was prepared from a combination of a commercial P25 with a mesopore structure and carbon spheres with a microporous structure with high CO2 adsorption capacity. Then, the obtained hybrid TiO2-carbon sphere photocatalysts were deposited on a glass fiber fabric. The combined TiO2-carbon spheres/silica cloth photocatalysts showed higher efficiency in the two-electron CO2 reduction towards CO than in the eight-electron reaction to methane. The 0.5 g graphitic carbon spheres combined with 1 g of TiO2 P25 resulted in almost 100% selectivity to CO. From a practical point of view, this is promising as it economically eliminates the need to separate CO from the gas mixture after the reaction, which also contains CH4 and H-2.
  • PozycjaOpen Access
    Influence of Potassium-Based Activation on Adsorptive Properties of Carbon SpheresModified with Iron(III) Citrate
    (MDPI, 2023-07-25) Pełech, Iwona; Sibera, Daniel; Staciwa, Piotr; Sobczuk, Konrad S.; Narkiewicz, Urszula; West Pomeranian University of Technology in Szczecin, Department of Inorganic Chemical Technology and Environmental Engineering, 70-322 Szczecin, ul Pułaskiego 10, Poland; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Budownictwa i Inżynierii Środowiska.
    Composites synthesized from iron(III) citrate and carbon spheres, and activated with potassium compounds were prepared and then characterized using XRD, SEM, and low-temperature nitrogen adsorption methods. The adsorption properties of the composites toward carbon dioxide were assessed using CO2 uptake measurement, as well as by measuring their selectivity toward carbon dioxide, given their further application as photocatalysts for the reduction of this gas. The effect of changing preparation conditions on the structural and adsorption properties of the material was assessed. The potential strength of such material is a synergistic effect between the high adsorption capacity related to the microporosity of carbon spheres combined with the catalytic properties of iron particles.
  • PozycjaOpen Access
    Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al) and its application for high-performance Zn-ion capacitor
    (KeAi Chinese Roots Global Impact, 2023) Li, Jiaxin; Zhang, Shuai; Hua, Yumeng; Lin, Yichao; Wen, Xin; Mijowska, Ewa; Tang, Tao; Chen, Xuecheng; Ruoff, Rodney; Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Piastów Ave. 42, 71-065, Szczecin, Poland; Key State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China; School of Safety Engineering, China University of Mining and Technology, Xuzhou, 221116, China; Institute of Advanced Electrical Materials, Qingdao University of Science and Technology, Qingdao, 266042, China; Institute for Basic Science Center for Multiple Dimensional Carbon Materials, Ulsan, 44919, Republic of Korea; Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea; Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej
    It is of great scientific and economic value to recycle waste poly (ethylene terephthalate) (PET) into high-value PET-based metal organic frameworks (MOFs) and further convert it into porous carbon for green energy storage applications. In the present study, a facile and cost-effective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53(Al) with a 100% conversation, then the MOF-derived porous carbon was assembled into electrodes for high-performance supercapacitors. The results indicated that the as-synthesized carbon exhibited high SSA of 1712 m2 g−1 and unique accordion-like structure with hierarchical porosity. Benefit to these advantageous characters, the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g−1 at the current density of 0.5 A g−1 and good rate capability of 73.6% capacitance retention at 20 A g−1 in 6M KOH electrolyte. Furthermore, the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g−1 at 0.1 A g−1, excellent cycling stability of 92.2% capacitance retention after 10 000 cycles and ultra-high energy density of 150.3 Wh kg−1 at power density of 90 W kg−1 in 3M ZnSO4 electrolyte. It is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF, and further expands the applications of MOF-derived carbons for high-performance energy storage devices, so it is conducive to both pollution alleviation and sustainable economic development.
  • PozycjaEmbargo
    Ultra-stable sandwich shaped flexible MXene/CNT@Ni films for high performance supercapacitor
    (Elsevier, 2023) Li, Shiyun; Zhang, Qiaoyu; Liu, Lina; Wang, Jiangang; Zhang, Ling; Shi, Minjie; Chen, Xuecheng; School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China; Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Piastów Ave. 42, 71-065 Szczecin, Poland; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej
    MXene exhibits high volume capacity, but poor flexibility and mechanical properties have seriously limited its further applications. To address this issue, a sandwich shaped flexible MXene/CNTs@Ni film has been fabricated via a simple filtration approach, wherein the nickel-electroless plating on CNTs (CNTs@Ni) are utilized as the effective interlayer spacers of MXene nanosheets to stabilize their layer structures. In addition, the optimized MXene/CNTs@Ni film electrode as a binder-free and self-supported electrode exhibits robust mechanical stability and impressive electrochemical properties, especially with a high specific capacitance of 990.8 F cm−3, about 1.4 times and 2.4 times higher than that of MXene/CNTs film electrode and pristine MXene film electrode, respectively. A flexible symmetrical supercapacitor (FSMS) was constructed based on MXene/CNTs@Ni film. Notably, the FSMS owns a high energy density of 14.5 Wh kg−1, a high power density of 2571.4 W kg−1, and a good cycling stability, suggesting its potential application in portable energy technologies.
  • PozycjaOpen Access
    Recycling of Plastic Wastes for the Mass Production of Yolk−Shell-Nanostructured Co3O4@C for Lithium-Ion Batteries
    (ACS Publications, 2023) Li, Jiaxin; Dou, Fei; Gong, Jiang; Gao, Yanshen; Hua, Yumeng; Sielicki, Krzysztof; Zhang, Dengsong; Mijowska, Ewa; Chen, Xuecheng; Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin 71-065, Poland; School of Materials Science and Engineering and Research Center of Nano Science and Technology, Shanghai University, Baoshan, Shanghai 200444, China; Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Hongshan, Wuhan; School of Environment and Chemical Engineering, Shenyang University of Technology, Shenyang 110870, China; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej
    Facing the ever-increasing production of municipal plastics, great efforts have been made to recycle plastic waste into high value-added products. As the main components of plastic wastes, PP, PE and PS are uncharred polymers, which are hard to be carbonized under normal conditions. To address this issue, transition metal catalysts (Co3O4) were introduced to carbonize the plastic waste with high carbon yields. Herein, the mixed waste plastics (PP/PE/PS) were carbonized into yolk-shell structured Co3O4@carbon nanomaterials with high yield of 49 wt%. A high capacity of 1066 mAh g-1 at 0.1 A g-1 after 100 cycles in lithium-ion batteries. Moreover, the galvanostatic intermittent titration technique (GITT) results estimated that the YSS Co3O4@C possessed a higher Li+ diffusion coefficient, ensuring an improved cycling stability and rate performance. The present strategy not only provides a potential approach for recycling waste plastics into high-value carbon materials, but also shows the possibility for the mass production of high-performance nanosized anode materials for LIBs in a commercial way.
  • PozycjaEmbargo
    Influence of the calcination of TiO2-reduced graphite hybrid for the photocatalytic reduction of carbon dioxide
    (Elsevier, 2021-06-09) Morawski, Antoni Waldemar; Kusiak-Nejman, Ewelina; Wanag, Agnieszka; Narkiewicz, Urszula; Edelmannova, Miroslava; Reli, Martin; Koci, Kamila; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska; Technical University of Ostrava. Institute of Environmental Technology; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Inorganic Chemical Technology and Environment Engineering
    In this work, a conversion of carbon dioxide (CO2) into methane, carbon monoxide, as well as hydrogen was investigated. The TiO2/rGO photocatalysts were prepared by two steps: solvothermal method and calcination at 500, 800, and 1000 ◦C in an argon atmosphere. The obtained samples were characterized by X-ray diffraction (XRD), UV–vis diffuse reflection spectroscopy (UV–vis/DRS), N2 adsorption-desorption and analysis of carbon content. The activity of photocatalysts was evaluated in the photocatalytic reduction of CO2. The TiO2/rGO-10 without calcination showed the highest activity toward CO2 conversion. It was found that all samples after rGO modification exhibited good activity toward H2 generation with high selectivity. The enhanced photocatalytic performance was attributed mainly to the presence of graphene due to its excellent electron transport/collection ability.
  • PozycjaOpen Access
    DFT Calculation of Carbon-Doped TiO2 Nanocomposites
    (MDPI, 2023-09-07) Gustavsen, Kim Robert; Feng, Tao; Huang, Hao; Li, Gang; Narkiewicz, Urszula; Wang, Kaiying; Department of Microsystems, University of South-Eastern Norway, 3184 Horten, Norway; Institute of Energy Innovation, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska
    Titanium dioxide (TiO2) has been proven to be an excellent material for mitigating the continuous impact of elevated carbon dioxide concentrations. Carbon doping has emerged as a promising strategy to enhance the CO2 reduction performance of TiO2 . In this study, we investigated the effects of carbon doping on TiO2 using density functional theory (DFT) calculations. Two carbon doping concentrations were considered (4% and 6%), denoted as TiO2 -2C and TiO2 -3C, respectively. The results showed that after carbon doping, the band gaps of TiO2 -2C and TiO2-3C were reduced to 1.58 eV and 1.47 eV, respectively, which is lower than the band gap of pure TiO2 (2.13 eV). This indicates an effective improvement in the electronic structure of TiO2. Barrier energy calculations revealed that compared to pure TiO2 (0.65 eV), TiO2 -2C (0.54 eV) and TiO2 -3C (0.59 eV) exhibited lower energy barriers, facilitating the transition to *COOH intermediates. These findings provide valuable insights into the electronic structure changes induced by carbon doping in TiO2, which can contribute to the development of sustainable energy and environmental conservation measures to address global climate challenges..
  • PozycjaOpen Access
    ZnO/Carbon Spheres with Excellent Regenerability for Post-Combustion CO2 Capture
    (MDPI, 2021-10-28) Pełech, Iwona; Sibera, Daniel; Staciwa, Piotr; Kusiak-Nejman, Ewelina; Kapica-Kozar, Joanna; Wanag, Agnieszka; Narkiewicz, Urszula; Morawski, Antoni W.; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Budownictwa i Inżynierii Środowiska. Katedra Budownictwa Ogólnego; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Inorganic Chemical Technology and Environment Engineering; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering. Department of General Civil Engineering
    This paper examines the synthesis of the ZnO/carbon spheres composites using resorcinol—formaldehyde resin as a carbon source and zinc nitrate as a zinc oxide source in a solvothermal reactor heated with microwaves. The influence of activation with potassium oxalate and modification with zinc nitrate on the physicochemical properties of the obtained materials and CO2 adsorption capacity was investigated. It was found that in the case of nonactivated material as well as activated materials, the presence of zinc oxide in the carbon matrix had no effect or slightly increased the values of CO2 adsorption capacity. Only for the material where the weight ratio of carbon:zinc was 2:1, the decrease of CO2 adsorption capacity was reported. Additionally, CO2 adsorption experiments on nonactivated carbon spheres and those activated with potassium oxalate with different amounts of zinc nitrate were carried out at 40 °C using thermobalance. The highest CO2 adsorption capacity at temperature 40 °C (2.08 mmol/g adsorbent) was achieved for the material after activation with potassium oxalate with the highest zinc nitrate content as ZnO precursor. Moreover, repeated adsorption/desorption cycle experiments revealed that the as-prepared carbon spheres were very good CO2 adsorbents, exhibiting excellent cyclic stability with a performance decay of less than 10% over up to 25 adsorption-desorption cycles.
  • PozycjaOpen Access
    Photocatalytic Reduction Efficiency of CO2 Depending on ZnO Particle Size
    (MDPI, 2023-09-03) Morawski, Antoni Waldemar; Gano, Marcin; Ćmielewska, Katarzyna; Kusiak-Nejman, Ewelina; Pełech, Iwona; Staciwa, Piotr; Ekiert, Ewa; Narkiewicz, Urszula; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Organicznej i Materiałów Polimerowych; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Inorganic Chemical Technology and Environment Engineering; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Organic Chemical Technology and Polymer Materials
    In the face of increasing global carbon dioxide emissions and the urgent need to mitigate climate change, the development of efficient and sustainable strategies for CO2 conversion has gained significant attention. One of the methods of eliminating the harmful effects of CO2 is its photoreduction. In this paper, ZnO was used as an effective photocatalyst for the photoreduction of CO2 in a gas-phase system. The influence of particle size on the process efficiency was investigated. The ZnO materials applied in the studies were characterized using XRD, SEM, and low-temperature nitrogen adsorption (BET) methods. The pore volume distribution was calculated based on the DFT method. The investigation confirmed that it had a significant impact on the formation of the product of photocatalysis carbon dioxide. The main identified product was carbon monoxide. Hydrogen and methane were detected as well. Based on the results, it was found that the process efficiency was enhanced with decreasing ZnO particle size, and the most effective catalyst for the photoreduction of CO2 was the ZnO sample with the smallest particle size (18 nm).
  • PozycjaOpen Access
    On the Selectivity of Simultaneous CO2 and N2 Reduction Using TiO2/Carbon Sphere Photocatalysts Prepared by Microwave Treatment and Mounted on Silica Cloth
    (MDPI, 2023-08-24) Kusiak-Nejman, Ewelina; Ćmielewska, Katarzytna; Pełech, Iwona; Ekiert, Ewa; Staciwa, Piotr; Sibera, Daniel; Wanag, Agnieszka; Kapica-Kozar, Joanna; Gano, Marcin; Narkiewicz, Urszula; Morawski, Antoni Waldemar; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Budownictwa i Inżynierii Środowiska. Katedra Budownictwa Ogólnego; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Organicznej i Materiałów Polimerowych; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Inorganic Chemical Technology and Environment Engineering; West Pomeranian University of Technology in Szczecin. Faculty of Civil and Environmental Engineering. Department of General Civil Engineering; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Chemical Organic Technology and Polymeric Materials
    This paper presents new photocatalysts obtained by treating carbon spheres (CS) and TiO2 in a microwave reactor at a pressure of 20 atm and a temperature of up to 300 °C for 15 min and then depositing TiO2/CS composites on glass fibre cloths. Such highly CO2-adsorbing photocatalysts showed photoactivity in the simultaneous water-splitting process, generating H2, reducing CO2 to CO and CH4, and reducing N2 to NH3. In addition, calculations of the hydrogen balance involved in all reactions were performed. Adding 1 g of carbon spheres per 1 g of TiO2 maintained the high selectivity of nitrogen fixation at 95.87–99.5%, which was continuously removed from the gas phase into the water as NH4+ ions.
  • PozycjaOpen Access
    The influence of the addition of carbon spheres on photoactivity of TiO2 and ZnO in CO2 reduction process
    (Elsevier, 2023-09-09) Morawski, Antoni W.; Ćmielewska, Katarzyna; Kusiak-Nejman, Ewelina; Staciwa, Piotr; Kapica-Kozar, Joanna; Ekiert, Ewa; Pełech, Iwona; Narkiewicz, Urszula; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej. Katedra Technologii Chemicznej Nieorganicznej i Inżynierii Środowiska; West Pomeranian University of Technology in Szczecin. Faculty of Chemical Technology and Engineering. Department of Inorganic Chemical Technology and Environment Engineering
    The development of an effective photocatalyst for CO2 reduction is currently being addressed by many scientists. This study concerns the influence of the addition of carbon spheres (CS) on photoactivity of TiO2 and ZnO. The photocatalysts were tested in a liquid phase system in an alkaline environment. The suspensions of the tested materials were irradiated with UV–Vis light for 6 h. Then, the amount of the obtained products in the gas phase was analysed by gas chromatography. The identified products of CO2 photoreduction were hydrogen, carbon monoxide, and methane. Based on the results, it was found that CS/TiO2 and CS/ZnO showed similar activity in carbon dioxide reduction processes, however, more product amounts were obtained in experiments with the use of CS/TiO2 materials. The addition of carbon spheres to titanium dioxide improved its activity in carbon monoxide production. The maximum photoactivity of CS/TiO2 was observed for the addition of 0.1 g of CS. On the other hand, in the case of CS/ZnO materials, carbon spheres did not positively affect their performance. Nevertheless, their activity increased with the CS amount.
  • PozycjaOpen Access
    The influence of the synthesis pH on the morphology and adsorption properties of carbon spheres
    (Elsevier, 2023-07-13) Sobczuk, Konrad S.; Pełech, Iwona; Narkiewicz, Urszula; Staciwa, Piotr; Sibera, Daniel; Moszyński, Dariusz; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering; Faculty of Civil and Environmental Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering
    Microporous spherical carbon materials were obtained from the resorcinol–formaldehyde resin, treated in a solvothermal reactor heated with microwaves, and then subjected to carbonization. The effect of the pH on the changes in the carbon spheres' morphology and the adsorption performance was investigated. In order to improve the adsorption efficiency, carbon spheres were subjected to the activation using potassium hydroxide and their properties were compared to those of the non-activated ones. The adsorption performance of the produced materials was evaluated in detail by examining nitrogen and carbon dioxide adsorption from the gas phase, the morphology – using Scanning Electron Microscopy, and surface chemistry – using X-ray Photoelectron Spectroscopy.
  • PozycjaOpen Access
    CO2 Adsorption Study of Potassium‐Based Activation of Carbon Spheres
    (MDPI, 2022-07-05) Pełech, Iwona; Staciwa, Piotr; Sibera, Daniel; Pełech, Robert; Sobczuk, Konrad S.; Kayalar, Gulsen Yagmur; Narkiewicz, Urszula; Cormia, Robert; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Faculty of Civil and Environmental Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Department of Chemical Engineering, Faculty of Engineering, Eskişehir Technical University, 26555 Eskişehir, Turkey; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Chemistry Faculty, Chemistry Department, Foothill College
    The adsorption properties of microporous spherical carbon materials obtained from the resorcinol-formaldehyde resin, treated in a solvothermal reactor heated with microwaves and then subjected to carbonization, are presented. The potassium-based activation of carbon spheres was carried out in two ways: solution-based and solid-based methods. The effect of various factors, such as chemical agent selection, chemical activating agent content, and the temperature or time of activation, was investigated. The influence of microwave treatment on the adsorption properties was also investigated and described. The adsorption performance of carbon spheres was evaluated in detail by examining CO2 adsorption from the gas phase.
  • PozycjaOpen Access
    Pressureless and Low-Pressure Synthesis of Microporous Carbon Spheres Applied to CO2 Adsorption
    (MDPI, 2020-10-13) Pełech, Iwona; Sibera, Daniel; Staciwa, Piotr; Narkiewicz, Urszula; Cormia, Robert; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Faculty of Civil and Environmental Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydział Technologii i Inżynierii Chemicznej; Department of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin; Chemistry Faculty, Chemistry Department, Foothill College
    In this work, low-pressure synthesis of carbon spheres from resorcinol and formaldehyde using an autoclave is presented. The influence of reaction time and process temperature as well as the e ect of potassium oxalate, an activator, on the morphology and CO2 adsorption properties was studied. The properties of materials produced at pressureless (atmospheric) conditions were compared with those synthesized under higher pressures. The results of this work show that enhanced pressure treatment is not necessary to produce high-quality carbon spheres, and the morphology and porosity of the spheres produced without an activation step at pressureless conditions are not significantly di erent from those obtained at higher pressures. In addition, CO2 uptake was not a ected by elevated pressure synthesis. It was also demonstrated that addition of the activator (potassium oxalate) had much more e ect on key properties than the applied pressure treatment. The use of potassium oxalate as an activator caused non-uniform size distribution of spherical particles. Simultaneously higher values of surface area and total pore volumes were reached. A pressure treatment of the carbon materials in the autoclave significantly enhanced the CO2 uptake at 25 C, but had no e ect on it at 0 C.