In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a co... more In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra with high spatial resolution. Based on the impedance spectra analysis with an appropriate electric equivalent circuit, it was possible to map surface resistance and contact capacitance. Polycrystalline heavy boron-doped diamond (BDD) electrodes were the research object. Recent studies have shown that the exposure of such electrodes to oxidizing environment may result in the modification of termination type, and thus it is a key factor in describing the electric and electrochemical properties of BDD. We have successfully applied multifrequency NIM, which all...
Additive manufacturing, called 3D printing, starts to play an unprecedented role in developing ma... more Additive manufacturing, called 3D printing, starts to play an unprecedented role in developing many applications in industrial or personalized products. The conductive composite structures require additional treatment to achieve an electroactive surface useful for electrochemical devices. In this paper, the surfaces of carbon black/poly(lactic acid) CB-PLA printouts were activated by electrolysis or enzymatic digestion with proteinase K, or a simultaneous combination of both. Proposed modification protocols allowed for tailoring electrochemically active surface area and electron transfer kinetics determined by electrochemical techniques (CV, EIS) with [Fe(CN)6]4-/3- redox probe. The X-ray photon spectroscopy and SEM imaging were applied to determine the delivered surface chemistry. The CB-PLA hydrolysis in alkaline conditions and under anodic polarization greatly impacts the charge transfer kinetics. The enzymatic hydrolysis of PLA with proteinase K has led to highly efficient resul...
In this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were stu... more In this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were studied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation using diazonium salts. The modified GC electrodes are sensitive to oxygen, determined by cyclic voltammetry. Changes in the oxygen determination efficiency depend mostly on the length of the side chain AQ derivative which is grafted to the GC electrode and is nearly double in comparison to a bare GC electrode modified by 1-((2-((2-aminoethyl)amino)ethyl)amino)-9,10-anthraquinone.
The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors... more The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the reference compound to evaluate the efficiency of the remainder. In this respect, two structural factors were examined, namely, (i) the effect of replacement of the S-atom of diaryl sulfide by SO or SO2 group, (ii) the effect of the introduction of an electron-withdrawing or an electron-donating group in the aryl moiety. Two computational chemical approaches were used to achieve the objectives: the density functional theory (DFT) and the Monto Carlo (MC) simulation. First, B3LYP/6-311+G(d,p) model chemistry was employed to calculate quantum chemical descript...
In this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath c... more In this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest average amount of included TiO2 is 1.7 wt.%, in the case of the bath containing 5 g/L thereof. Composite coatings showed significantly improved antibacterial properties towards E. coli ATCC 8739 bacteria as compared to the Cu–Sn coatings of the same composition. Such improvement has been connected with the corrosion resistance of the composites studied by linear polarization and electrochemical impedance spectroscopy. In the bacterial media and 3% NaCl solutions, Cu–Sn–TiO2 composite coatings have lower corrosion resistance as compared to Cu–Sn alloys, which...
BiOX (X = Cl, Br, I) photocatalysts with dominant (110) facets were synthesized via a mannitol-as... more BiOX (X = Cl, Br, I) photocatalysts with dominant (110) facets were synthesized via a mannitol-assisted solvothermal method. This is the first report on the exposed (110) facets-, size-, and defects-controlled synthesis of BiOX achieved by solvothermal synthesis with mannitol. This polyol alcohol acted simultaneously as a solvent, capping agent, and/or soft template. The mannitol concentration on the new photocatalysts morphology and surface properties was investigated in detail. At the lowest concentration tested, mannitol acted as a structure-directing agent, causing unification of nanoparticles, while at higher concentrations, it functioned as a solvent and soft template. The effect of exposed (110) facet and surface defects (Bi(3−x)+, Bi4+, Bi5+) of BiOX on the photocatalytic activity of nanomaterials under the UV–Vis irradiation were evaluated by oxidation of Rhodamine B (RhB) and 5-fluorouracil (5-FU), an anticancer drug, and by reduction of Cr(VI). Additionally, the influence...
Abstract This paper focuses on the synthesis route and electrochemical properties of electrocatal... more Abstract This paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60-90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working laser parameters that allow for fabrication of material possessing the highest performance towards glucose oxidation. It is proven that laser-engineered electrodes have an improved stability in acidic conditions and higher response from glucose oxidation in both alkaline and neutral environment in comparison to analogs obtained by conventional furnace dewetting. In neutral electrolyte it is also observed that the current density increases by almost 300% while the change in mechanism of glucose oxidation was identified due to laser treatment. It is suggested that laser dewetted gold nanoparticles have more surface defects than furnace dewetted ones so that more AuOHads species are created and therefore catalytic activity of the material is enhanced. These results indicate a scalable and cost-effective fabrication route and are important for the current research on non-enzymatic glucose sensors.
Abstract Recovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great atten... more Abstract Recovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great attention because of high amount of neodymium and potential risk of environmental pollution. In this study, a novel environment-friendly hydrometallurgical route is proposed for efficient recovery of REEs during electrochemical leaching with sulfuric and oxalic acids. With proper adjustment of the electrolyte composition and operating conditions, effective separation of different elements is observed; a compact layer of REE oxalates in a purity of up to 93% is obtained on the cathode, while iron remains in the solution and as solid residue for further recovery. The mechanisms during the electro-leaching process were subsequently investigated and we propose that cathodic deposition of the REEs is due to electrostatic attraction of the REE-oxalate particles on the cathode. With this finding, selective recovery of REEs from spent magnets can be achieved. This study provides a new insight on electronic waste recycling by implementing principles of electrochemistry.
In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanopa... more In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation and reuse of the nanometer-sized photocatalyst from the suspension after the treatment process. The obtained Fe3O4@SiO2/d-TiO2-Pt/Cu photocatalysts were characterized by X-ray diffractometry (XRD) and specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Further, the mechanism of phenol degradation and the role of four oxidative species (h+, e−, •OH, and •O2−) in the studied photocatalytic process were investigated.
In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a co... more In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra with high spatial resolution. Based on the impedance spectra analysis with an appropriate electric equivalent circuit, it was possible to map surface resistance and contact capacitance. Polycrystalline heavy boron-doped diamond (BDD) electrodes were the research object. Recent studies have shown that the exposure of such electrodes to oxidizing environment may result in the modification of termination type, and thus it is a key factor in describing the electric and electrochemical properties of BDD. We have successfully applied multifrequency NIM, which all...
Additive manufacturing, called 3D printing, starts to play an unprecedented role in developing ma... more Additive manufacturing, called 3D printing, starts to play an unprecedented role in developing many applications in industrial or personalized products. The conductive composite structures require additional treatment to achieve an electroactive surface useful for electrochemical devices. In this paper, the surfaces of carbon black/poly(lactic acid) CB-PLA printouts were activated by electrolysis or enzymatic digestion with proteinase K, or a simultaneous combination of both. Proposed modification protocols allowed for tailoring electrochemically active surface area and electron transfer kinetics determined by electrochemical techniques (CV, EIS) with [Fe(CN)6]4-/3- redox probe. The X-ray photon spectroscopy and SEM imaging were applied to determine the delivered surface chemistry. The CB-PLA hydrolysis in alkaline conditions and under anodic polarization greatly impacts the charge transfer kinetics. The enzymatic hydrolysis of PLA with proteinase K has led to highly efficient resul...
In this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were stu... more In this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were studied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation using diazonium salts. The modified GC electrodes are sensitive to oxygen, determined by cyclic voltammetry. Changes in the oxygen determination efficiency depend mostly on the length of the side chain AQ derivative which is grafted to the GC electrode and is nearly double in comparison to a bare GC electrode modified by 1-((2-((2-aminoethyl)amino)ethyl)amino)-9,10-anthraquinone.
The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors... more The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the reference compound to evaluate the efficiency of the remainder. In this respect, two structural factors were examined, namely, (i) the effect of replacement of the S-atom of diaryl sulfide by SO or SO2 group, (ii) the effect of the introduction of an electron-withdrawing or an electron-donating group in the aryl moiety. Two computational chemical approaches were used to achieve the objectives: the density functional theory (DFT) and the Monto Carlo (MC) simulation. First, B3LYP/6-311+G(d,p) model chemistry was employed to calculate quantum chemical descript...
In this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath c... more In this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest average amount of included TiO2 is 1.7 wt.%, in the case of the bath containing 5 g/L thereof. Composite coatings showed significantly improved antibacterial properties towards E. coli ATCC 8739 bacteria as compared to the Cu–Sn coatings of the same composition. Such improvement has been connected with the corrosion resistance of the composites studied by linear polarization and electrochemical impedance spectroscopy. In the bacterial media and 3% NaCl solutions, Cu–Sn–TiO2 composite coatings have lower corrosion resistance as compared to Cu–Sn alloys, which...
BiOX (X = Cl, Br, I) photocatalysts with dominant (110) facets were synthesized via a mannitol-as... more BiOX (X = Cl, Br, I) photocatalysts with dominant (110) facets were synthesized via a mannitol-assisted solvothermal method. This is the first report on the exposed (110) facets-, size-, and defects-controlled synthesis of BiOX achieved by solvothermal synthesis with mannitol. This polyol alcohol acted simultaneously as a solvent, capping agent, and/or soft template. The mannitol concentration on the new photocatalysts morphology and surface properties was investigated in detail. At the lowest concentration tested, mannitol acted as a structure-directing agent, causing unification of nanoparticles, while at higher concentrations, it functioned as a solvent and soft template. The effect of exposed (110) facet and surface defects (Bi(3−x)+, Bi4+, Bi5+) of BiOX on the photocatalytic activity of nanomaterials under the UV–Vis irradiation were evaluated by oxidation of Rhodamine B (RhB) and 5-fluorouracil (5-FU), an anticancer drug, and by reduction of Cr(VI). Additionally, the influence...
Abstract This paper focuses on the synthesis route and electrochemical properties of electrocatal... more Abstract This paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60-90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working laser parameters that allow for fabrication of material possessing the highest performance towards glucose oxidation. It is proven that laser-engineered electrodes have an improved stability in acidic conditions and higher response from glucose oxidation in both alkaline and neutral environment in comparison to analogs obtained by conventional furnace dewetting. In neutral electrolyte it is also observed that the current density increases by almost 300% while the change in mechanism of glucose oxidation was identified due to laser treatment. It is suggested that laser dewetted gold nanoparticles have more surface defects than furnace dewetted ones so that more AuOHads species are created and therefore catalytic activity of the material is enhanced. These results indicate a scalable and cost-effective fabrication route and are important for the current research on non-enzymatic glucose sensors.
Abstract Recovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great atten... more Abstract Recovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great attention because of high amount of neodymium and potential risk of environmental pollution. In this study, a novel environment-friendly hydrometallurgical route is proposed for efficient recovery of REEs during electrochemical leaching with sulfuric and oxalic acids. With proper adjustment of the electrolyte composition and operating conditions, effective separation of different elements is observed; a compact layer of REE oxalates in a purity of up to 93% is obtained on the cathode, while iron remains in the solution and as solid residue for further recovery. The mechanisms during the electro-leaching process were subsequently investigated and we propose that cathodic deposition of the REEs is due to electrostatic attraction of the REE-oxalate particles on the cathode. With this finding, selective recovery of REEs from spent magnets can be achieved. This study provides a new insight on electronic waste recycling by implementing principles of electrochemistry.
In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanopa... more In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation and reuse of the nanometer-sized photocatalyst from the suspension after the treatment process. The obtained Fe3O4@SiO2/d-TiO2-Pt/Cu photocatalysts were characterized by X-ray diffractometry (XRD) and specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Further, the mechanism of phenol degradation and the role of four oxidative species (h+, e−, •OH, and •O2−) in the studied photocatalytic process were investigated.
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Papers by Jacek Ryl