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The quest for highly efficient, stable, and economically viable bifunctional electrocatalysts is of paramount relevance for advancing in water splitting for the hydrogen energy sector, particularly in facilitating hydrogen (HER) and oxygen evolution evolution (OER) as cathodic and anodic reaction, respectively. In this study, two ionic liquids containing transition metal Fe or Cu, as well as a mixture of these ionic liquids, were used as precursors to synthesize Fe-, Cu-, and Fe,Cu-decorated carbon materials through simple, straightforward, and inexpensive carbonization processes. Comprehensive characterization via SEM-EDS, TEM, XRD, and XPS established the formation of Fe3O4 and Cu2O species. These materials were systematically evaluated for OER and HER in alkaline electrolyte. Fe,Cu-decorated carbon electrocatalyst exhibited favorable performance for OER, including a low onset potential, and reaching 10 and 50 mA cm−2 at overpotential values of 325 mV and 364 mV, respectively. Notably, grafting both Fe and Cu in the material further augmented its electrocatalytic properties, underscoring the enhanced potential of transition metal-decorated carbon materials for OER applications.

Low-cost non-noble metal electrocatalysts are currently the focus of research and development for energy conversion and storage devices. MXenes, the newest class of two-dimensional materials, have high surface area, nanometer layer thickness, hydrophilicity and high electrical conductivity that favor their performance for electrocatalytic reactions. Herein, niobium carbide MXene (Nb-MXene) was obtained from its MAX phase by chemical synthesis and characterized regarding its morphology, structure and electrochemical activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) as well as for charge storage in different electrolytic media. The results demonstrate the good performance of Nb-MXene for storing charge (104 F g−1 at 5 mV s−1) that increased remarkably with continuous cycling in an acidic medium. Current density for oxygen evolution of ∼32.5 mA cm−2 was reached in alkaline medium. The oxygen reduction reaction in the same media was observed to proceed via 2e− mechanism with a Tafel slope of 114 mV dec−1. Therefore, Nb-MXene presents characteristics and performance of a promising material for electrocatalytic reactions.

Three different iron-based electrocatalysts deposited on reduced graphene oxide (Fe/rGO, FeNi/rGO, and FeCu/ rGO) were synthesized and examined for oxygen reduction and evolution reactions (ORR and OER, respectively) in alkaline media. X-ray powder diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were used for a thorough investigation of physico-chemical properties of FeM/rGO electrocatalysts. XPS analysis indicated the presence of transition metals in higher oxidation states. Onset potentials during OER were found to be 1.51, 1.64, and 1.71 V for FeNi/rGO, FeCu/rGO, and Fe/rGO, respectively. Moreover, FeNi/rGO showed the highest OER current density (~40 mA cm benchmark OER electrocatalyst, IrO 2 2 at 2 V), two times higher than the -1 , and the lowest Tafel slope (88 mV dec ), lower than IrO . The somewhat better catalytic activity of Fe/rGO for ORR in alkaline media compared to FeNi/rGO and FeCu/rGO was noticed. Tafel slopes of 105, 112, and 113 mV dec 2-1 during ORR were found for Fe/rGO, FeCu/rGO, and FeNi/rGO, respectively. Almost constant ORR current densities during chronoamperometric measurements were noticed for Fe/rGO and FeCu/rGO indicating stable performance.

For the first time, composites of metal-organic framework MOF-5 and conjugated polymer polyaniline (PANI), (MOF-5/PANI), prepared using PANI in its conducting (emeraldine salt, ES) or nonconducting form (emeraldine base, EB) at various MOF-5 and PANI mass ratios, were evaluated as electrode materials for the electrochemical detection of cadmium (Cd2+) and lead (Pb2+) ions in aqueous solutions. Testing of individual components of composites, PANI-ES, PANI-EB, and MOF-5, was also performed for comparison. Materials are characterized by Raman spectroscopy, scanning electron microscopy (SEM) and dynamic light scattering (DLS), and their electrochemical behavior was discussed in terms of their zeta potential, structural, morphology, and textural properties. All examined composites showed high electrocatalytic activity for the oxidation of Cd and Pb to Cd2+ and Pb2+, respectively. The MOF/EB-1 composite (71.0 wt.% MOF-5) gave the highest oxidation currents during both individual and simultaneous detection of two heavy metal ions. Current densities recorded with MOF/EB-1 were also higher than those of its individual components, reflecting the synergistic effect where MOF-5 offers high surface area for two heavy metals adsorption and PANI offers a network for electron transfer during metals’ subsequent oxidation. Limits of detection using MOF/EB-1 electrode for Cd2+ and Pb2+ sensing were found to be as low as 0.077 ppm and 0.033 ppm, respectively. Moreover, the well-defined and intense peaks of Cd oxidation to Cd2+ and somewhat lower peaks of Pb oxidation to Pb2+ were observed at voltammograms obtained for the Danube River as a real sample with no pretreatment, which implies that herein tested MOF-5/PANI electrodes could be used as electrochemical sensors for the detection of heavy metal ions in the real water samples.

The potential of polyoxometalates (POMs) as alternatives to noble metal-based bifunctional electrocatalysts for air electrode, i.e., for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), was analyzed herein. Five POMs containing transition metal (Mn, Fe, Co, Ni, or Cu) were prepared and combined with reduced graphene oxide (rGO). Kenning structure of POMs with nanolamellae-like morphology and multi-layered graphene sheets of rGO were confirmed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy and Raman spectroscopy analysis. Different POM:rGO ratios were tested to optimize the composition, and a ratio of 1:5 Ni- POM:rGO was found to be the most electrocatalytically active for OER (Tafel slope as low as 42 mV dec 1, overpotential at 10 mA cm2 of 354 mV and current density at 400 mV overpotential as high as 83.4 mA cm2), notably better than IrO2. As for ORR, Co-POM/rGO carried the lowest Tafel slope of 165 mV dec 1, half-wave potential of 0.711 V and a mixed 2- and 4-electron ORR mechanism. Moreover, these non-precious metal electrocatalysts showed stability in alkaline media with no change in their structure.

We present the synthesis and characterization of two monometallic coordination polymers, [Co(L)2(H2O)2]n (Co-CP) and [Ni(L)2(H2O)2]n (Ni-CP), alongside a heterobimetallic counterpart, CoNi-CP, derived from an amide-based multifunctional pro-ligand 4-(pyrimidin-5-ylcarbamoyl)benzoic acid (HL), and discussed their electrocatalytic activity in the oxygen evolution reaction (OER). The CPs were characterized using various techniques, including elemental analysis, IR spectroscopy, X-ray diffraction, and thermal and powder XRD analyses. The low-cost amide-functionalized transition metal pristine coordination polymers Co-CP and Ni-CP were demonstrated to catalyze the OER in alkaline media, surpassing the benchmark IrO2 electrocatalyst performance. The heterometallic coordination polymer (CoNi-CP) displayed a lower Tafel slope value (and thus, faster kinetics) and higher long-term durability compared to its monometallic counterparts, Co-CP and Ni-CP. The results obtained show a pristine transition metal heterobimetallic coordination polymer as a low-cost electrocatalyst of great promise and high performance for OER catalysis in alkaline media.

In order to reduce air pollution by green-house gases released during fossil fuels combustion, hydrogen has been suggested as an alternative, clean fuel [1]. The most promising method of obtaining green hydrogen (and oxygen) is electrolytic water splitting [2]. For splitting process to be efficient, it is necessary to useelectrocatalysts with high activity, but they should also be economically accessible. Ionic liquids are used in the most diverse fields of sciencedue to their unique physical and chemical properties, and in this regard, they can be used for the development of electrocatalystsby direct carbonization [3]. Within this study, carbon catalysts doped with iron and copper (Fe/C, Cu/C and FeCu/C) were prepared by carbonization of ionic liquids containing the corresponding metal and characterized for the hydrogen evolution reaction (HER) in alkaline (8 M KOH) media. Electrochemical measurements were made by cyclic voltammetry (CV), linear cyclic voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). All electrocatalysts showed good activity for HER. Tafel slope (b) values of -132, 155 and -151 mV dec-1 (Table 1) were obtained for HER at 25 oC for Fe/C, Cu/C and FeCu/C, respectively. Also, the exchange current density (j0) was determined and the values ranged from 1.28 to 2.94 10-2 mAcm-2. The results (Table 1) show that Fe/C, Cu/C and FeCu/Care promisingelectrocatalysts for hydrogen gas production by water splitting.

Porous cobalt (III) oxide (Co3O4) and mixed cobalt (III) oxide - tin oxide (Co3O4/SnO2) were prepared by a novel template-based hydrothermal method resulting in their spherical morphology as confirmed by thorough physico-chemical characterisation. Two oxides were systematically examined as bifunctional electrocatalysts for oxygen reduction (ORR) and evolution (OER) reaction in alkaline media by voltammetry with rotating disk electrode, electrochemical impedance spectroscopy, and chronoamperometry. Low-cost Co3O4 and Co3O4/SnO2 electrocatalysts showed excellent ORR performance with low onset and half-wave potential, low Tafel slope, and the number of exchange electrons near 4, comparable to the commercial Pt/C electrocatalyst. Low OER onset potential of 1.52 and 1.57 V was observed for Co3O4 and Co3O4/SnO2, respectively, with low charge transfer resistance under anodic polarization conditions. Finally, to test bifunctional activity and durability of the two electrocatalyst, switch OER/ORR test was carried out.

Oxygen evolution reaction (OER) represents the efficiency-limiting reaction in water electrolyzers, metal-air batteries, and unitized regenerative fuel cells. To achieve high-efficiency OER in alkaline media, we fabricated three novel electrocatalysts by the assembly of as-prepared Co45Pt55 alloy nanoparticles (NPs) on three different carbon-based support materials: reduced graphene oxide (CoPt/rGO), mesoporous graphitic carbon nitride (CoPt/mpg-CN), and commercial Ketjenblack carbon (CoPt/KB). Voltammetry studies revealed that CoPt/rGO electrocatalyst provided lower OER overpotentials accompanied by higher currents and specific current density values than the other two studied materials. Moreover, CoPt/rGO outperformed commercial CoPt/C electrocatalysts in terms of notably higher specific current densities. Additionally, it was found that CoPt/rGO electrocatalyst activity increases with increasing temperature up to 85°C, as suggested by the increase in the exchange current density. Electrochemical impedance spectroscopy studies of three electrocatalysts in OER revealed similar charge transfer resistance, although CoPt/rGO provided a higher current density. The main issue observed during long-term chronoamperometry and chronopotentiometry studies is the materials’ instability under OER polarization conditions, which is still to be tackled in future work.

The catalytic activity of five silver-polyaniline-polyvinylpyrrolidone (Ag@PANI@PVP1–5) nanocomposites for borohydride oxidation reaction (BOR) was thoroughly examined. The nanocomposites were synthesized by an in situ chemical oxidative polymerization of aniline monomer by Ag+ ions in the presence of accelerator – PVP and physicochemical properties were determined prior their use in electrocatalysis. Ag@PANI@PVP3 with 35.4 wt% Ag delivered the highest current density and specific current density during BOR. Evaluation of the order of reaction < 1 suggested indirect BOR mechanism. Furthermore, Ag@PANI@PVP3 also delivered the highest current density and stable performance during chronoamperometric study of BOR. Its apparent activation energy of 15 kJ mol−1 was found to be the lowest among the studied materials accounting for the high current densities. © 2023 The Author(s)

Porous cobalt (III) oxide (Co3O4) and mixed cobalt (III) oxide - tin oxide (Co3O4/SnO2) were prepared by a novel template-based hydrothermal method resulting in their spherical morphology as confirmed by thorough physico-chemical characterisation. Two oxides were systematically examined as bifunctional electrocatalysts for oxygen reduction (ORR) and evolution (OER) reaction in alkaline media by voltammetry with rotating disk electrode, electrochemical impedance spectroscopy, and chronoamperometry. Low-cost Co3O4 and Co3O4/SnO2 electrocatalysts showed excellent ORR performance with low onset and half-wave potential, low Tafel slope, and the number of exchange electrons near 4, comparable to the commercial Pt/C electrocatalyst. Low OER onset potential of 1.52 and 1.57 V was observed for Co3O4 and Co3O4/SnO2, respectively, with low charge transfer resistance under anodic polarization conditions. Finally, to test bifunctional activity and durability of the two electrocatalyst, switch OER/ORR test was carried out.

Direct liquid fuel cells represent one of the most rapidly emerging energy conversion devices. The main challenge in developing fuel cell devices is finding low-cost and highly active catalysts. In this work, PET bottle waste was transformed into nitrogen-doped graphene (NG) as valuable catalyst support. NG was prepared by a one-pot thermal decomposition process of mineral water waste bottles with urea at 800 °C. Then, NG/Pt electrocatalysts with Pt loadings as low as 0.9 wt.% and 1.8 wt.% were prepared via a simple reduction method in aqueous solution at room temperature. The physical and electrochemical properties of the NG/Pt electrocatalysts are characterized and evaluated for application in direct borohydride peroxide fuel cells (DBPFCs). The results show that NG/Pt catalysts display catalytic activity for borohydride oxidation reaction, particularly the NG/Pt_1, with a number of exchanged electrons of 2.7. Using NG/Pt composite in fuel cells is anticipated to lower prices and boost the usage of electrochemical energy devices. A DBPFC fuel cell using NG/Pt_1 catalyst (1.8 wt.% Pt) in the anode achieved a power density of 75 mW cm−2 at 45 °C. The exceptional performance and economic viability become even more evident when expressed as mass-specific power density, reaching a value as high as 15.8 W mgPt−1.

Development of cost-effective, bi-functional carbon electrocatalysts via direct carbonization of ionic liquids (bis(cholinium) tetrachlorocobaltate(II) ([Ch]2[CoCl4]) and bis(1-butyl-3-methylimidazolium) tetrachlorocobaltate(II) ([Bmim]2[CoCl4])) is reported herein for the first time. Carbon electrocatalysts, dual-doped with cobalt and nitrogen, were tested for oxygen reduction (ORR) and oxygen evolution (OER) reactions. Both materials show high bi-functional catalytic activity and excellent stability due to synergistic effects arising from the presence of nitrogen and cobalt. Electrocatalyst prepared by carbonization of [Ch]2[CoCl4] show exceptional activity and selectivity toward ORR. Conversely, electrocatalyst prepared from [Bmim]2[CoCl4] showed a slightly better OER performance indicating that different catalytic sites are responsible for O2 reduction and H2O oxidation. Parent CoO particles with graphitic nitrogen boost activity for ORR, while elemental Co supported by nitrogen atoms is responsible for OER activity. Finally, energy consumption during electrolytic oxygen production was calculated revealing energy saving when using two materials as anode electrocatalysts.

Electrochemical water dissociation involves two reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), at the cathode and anode, respectively [1]. Water electrolysis could be sustainable and clean production of hydrogen as fuel, but HER and OER rates need to be improved for industrial applications. The OER involves the transport of four electrons which requires a high overvoltage to reach a satisfactory current density [1]. OER: 4OH- → 2H2O + O2 + 4e- Numerous studies have been focused on synthesizing high-performance and low-cost anode materials [2]. Metal oxides and metal chalcogenides are recognized as promising electrocatalysts for OER [3]. They can be synthesized using various methods with a wide range of precursors. Herein cobalt (III) oxide (Co3O4) and cobalt (III) oxide combined with tin oxide (Co3O4/SnO2) were examined for OER in alkaline media by linear sweep voltammetry (LSV). A three-electrode system was used for electrochemical examination where saturated calomel electrode (SCE) and graphite rod were set as reference and counter electrodes, while Co3O4 and Co3O4/SnO2 were used as the working electrodes. All potentials in this paper were given versus reversible hydrogen electrode (RHE). Fig. 1 shows OER polarization curves of Co3O4 and Co3O4/SnO2 electrocatalysts in alkaline media where both electrocatalysts showed high OER activity. Still, Co3O4/SnO2 gave an almost three times higher OER current density of 98 mA cm-2 than Co3O4 electrocatalyst (30 mA cm-2) at 1.85 V. Tafel slopes were found to be 207 and 156 mV dec-1 for Co3O4 and Co3O4/SnO2 electrocatalysts, respectively. A lower slope means that less overpotential is required to get a high current. In this case, Co3O4/SnO2 has a lower Tafel’s slope which indicates synergetic effect of coupling two metal oxides when it comes to electro-oxidation of oxygen in alkaline media [1]. The iridium (IV) and ruthenium (IV) oxides (IrO2 and RuO2) as the best OER electrocatalysts

Copper-silver and cobalt-silver alloy nanoparticles deposited on reduced graphene oxide (CuAg/rGO and CoAg/rGO) were synthesized and examined as electrocatalysts for oxygen reduction reaction (ORR) and hydrogen peroxide reduction reaction (HPRR) in alkaline media. Characterization of the prepared samples was done by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), and scanning electron microscopy with integrated energy-dispersive X-ray spectroscopy (SEM-EDS). CuAg/rGO and CoAg/rGO nanoparticles diameter ranged from 0.4 to 9.2 nm. The Ag loading was ca. 40 wt.% for both electrocatalysts, with that for Cu and Co being 35 and 17 wt.%, respectively. CoAg/rGO electrocatalyst showed a Tafel slope of 109 mV dec−1, significantly lower than that for CuAg/rGO (184 mV dec−1), suggesting faster ORR kinetics. Additionally, a higher diffusion current density was obtained for CoAg/rGO (−2.63 mA cm−2) than for CuAg/rGO (−1.74 mA cm−2). The average value of the number of electrons transferred during ORR was 2.8 for CuAg/rGO and 3.3 for CoAg/rGO electrocatalyst, further confirming the higher ORR activity of the latter. On the other hand, CuAg/rGO showed higher peak current densities (−3.96 mA cm−2) for HPRR compared to those recorded for CoAg/rGO electrocatalyst (−1.96 mA cm−2).

Gold polypyrrole (AuPPy) and copper polypyrrole (CuPPy) nanocomposites were prepared by a simple one-step in situ oxidative polymerization of pyrrole monomer by Au3+ and Cu2+ ions. Owing to their characteristic physicochemical properties confirmed by optical and structural characterization methods, the behavior of these materials as electrocatalysts for borohydride oxidation reaction (BOR) was considered. BOR apparent activation energy was found to be 16 and 22 kJ mol−1 for AuPPy and CuPPy electrocatalyst, respectively. The stability of the two electrocatalysts was assessed by chronoamperometry. Moreover, fuel cell tests were carried out with AuPPy and CuPPy as anode electrocatalyst of a direct borohydride-peroxide fuel cell (DBPFC). Open circuit voltage (OCV) of 1.30 V was obtained with both AuPPy and CuPPy, with the OCV increasing to 1.45 V upon adding a small amount of carbon (AuPPy-C). The peak power density of a DBPFC with BOR at AuPPy-C anode and hydrogen peroxide reduction reaction at Pt cathode was found to be ca. 162 mW cm−2 at 65 °C.

Development of cost-effective, bi-functional carbon electrocatalysts via direct carbonization of ionic liquids (bis(cholinium) tetrachlorocobaltate(II) ([Ch]2[CoCl4]) and bis(1-butyl-3-methylimidazolium) tetrachlorocobaltate(II) ([Bmim]2[CoCl4])) is reported herein for the first time. Carbon electrocatalysts, dual-doped with cobalt and nitrogen, were tested for oxygen reduction (ORR) and oxygen evolution (OER) reactions. Both materials show high bi-functional catalytic activity and excellent stability due to synergistic effects arising from the presence of nitrogen and cobalt. Electrocatalyst prepared by carbonization of [Ch]2[CoCl4] show exceptional activity and selectivity toward ORR. Conversely, electrocatalyst prepared from [Bmim]2[CoCl4] showed a slightly better OER performance indicating that different catalytic sites are responsible for O2 reduction and H2O oxidation. Parent CoO particles with graphitic nitrogen boost activity for ORR, while elemental Co supported by nitrogen atoms is responsible for OER activity. Finally, energy consumption during electrolytic oxygen production was calculated revealing energy saving when using two materials as anode electrocatalysts.

Six cobalt gold (CoAu) electrodes were prepared by electroless deposition using different gold-containing solutions (acidic and weakly acidic) and different Au deposition times. Characterization of CoAu electrodes was done by scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2-sorption, and X-ray powder diffraction techniques. The possibility of using the prepared electrodes in environmental applications, i.e., for the electrochemical sensing of a trace amount of arsenic(iii) in weakly alkaline media was assessed. Employing the CoAu electrode (prepared by immersing Co/Cu into 1 mM HAuCl4 (pH 1.8) at 30 °C for 30 s) under optimized conditions (deposition potential −0.7 V and deposition time of 60 s), a low limit of detection of 2.16 ppb was obtained. Finally, this CoAu electrode showed activity for arsenic oxidation in the presence of Cu(ii) as a model interferent as well as in real samples. Furthermore, the use of CoAu electrode as an anode in fuel cells, namely, direct borohydride - hydrogen peroxide fuel cells was also assessed. A peak power density of 191 mW cm−2 was attained at 25 °C for DBHPFC with CoAu anode at a current density of 201 mA cm−2 and cell voltage of 0.95 V, respectively. The peak power density further increased with the increase of the operating temperature to 55 °C.

A detailed examination of the principle of operation behind the functioning of the full-self-powered humidity sensor is presented. The sensor has been realized as a structure consisting of an interdigitated capacitor with aluminum thin-film digits. In this work, the details of its fabrication and activation are described in detail. The performed XRD, FTIR, SEM, AFM, and EIS analyses, as well as noise measurements, revealed that the dominant process of electricity generation is the electrochemical reaction between the sensor’s aluminum electrodes and the water from humid air in the presence of oxygen, which was the main goal of this work. The response of the sensor to human breath is also presented as a demonstration of its possible practical application.

Nanocomposites of gold nanoparticles (AuNPs) and conducting polymers, polypyrrole (PPy) and polyaniline (PANI), were prepared by simple oxidative polymerization of the corresponding monomer (pyrrole and aniline, respectively) by tetrachloroauric acid. Au nanospheres and nanorods were formed in the case of Au@PPy and Au@PANI, respectively. Detection of As(III) using Au@polymer was investigated where both nanocomposites showed similar activity for As electrooxidation in acidic media. The activity of Au@PPy was notably improved upon the addition of a small amount of conducting carbon, giving higher current densities compared to the commercial Au electrode. Further optimization of the operational conditions including electrolyte composition, deposition time and potential, was carried out to reach the limit of quantification as low as 2 ppb. Au@PPy nanocomposite proved to be suitable for sensing of As(III) in the presence of other ions, such as Cu(II). Furthermore, it proved to be suitable for As(III) sensing in real samples.

Nanocomposites of gold nanoparticles (AuNPs) and conducting polymers, polypyrrole (PPy) and polyaniline (PANI), were prepared by simple oxidative polymerization of the corresponding monomer (pyrrole and aniline, respectively) by tetrachloroauric acid. Au nanospheres and nanorods were formed in the case of Au@PPy and Au@PANI, respectively. Detection of As(III) using Au@polymer was investigated where both nanocomposites showed similar activity for As electrooxidation in acidic media. The activity of Au@PPy was notably improved upon the addition of a small amount of conducting carbon, giving higher current densities compared to the commercial Au electrode. Further optimization of the operational conditions including electrolyte composition, deposition time and potential, was carried out to reach the limit of quantification as low as 2 ppb. Au@PPy nanocomposite proved to be suitable for sensing of As(III) in the presence of other ions, such as Cu(II). Furthermore, it proved to be suitable for As(III) sensing in real samples.

A detailed examination of the principle of operation behind the functioning of the full-self-powered humidity sensor is presented. The sensor has been realized as a structure consisting of an interdigitated capacitor with aluminum thin-film digits. In this work, the details of its fabrication and activation are described in detail. The performed XRD, FTIR, SEM, AFM, and EIS analyses, as well as noise measurements, revealed that the dominant process of electricity generation is the electrochemical reaction between the sensor’s aluminum electrodes and the water from humid air in the presence of oxygen, which was the main goal of this work. The response of the sensor to human breath is also presented as a demonstration of its possible practical application.

Cerium oxide (CeO 2-δ ) ultrafine nanoparticles, with the lower (CeO 2-δ -HT) and higher (CeO 2-δ -SS) fraction of oxygen vacancies, were used as anchoring sites for the polymerization of aniline in acidic medium. As a result, polyaniline-emeraldine salt (PANI-ES)-based composites (PANI-ES@CeO 2-δ -HT and PANI-ES@CeO 2-δ -SS) were obtained. The interaction between CeO 2-δ and PANI was examined by FTIR and Raman spectroscopy. The PANI polymerization is initiated via electrostatic interaction of anilinium cation and Cl − ions (adsorbed at the protonated hydroxyl groups of CeO 2-δ ), and proceeds with hydrogen and nitrogen interaction with oxide nanoparticles. Tailoring the oxygen vacancy population of oxide offers the possibility to control the type of PANI-cerium oxide interaction, and consequently structural, electrical, thermal, electronic and charge storage properties of composite. A high capacitance of synthesized materials, reaching ∼294 F g −1 (PANI-ES), ∼299 F g −1 (PANI-ES@CeO 2-δ -HT) and ∼314 F g −1 (PANI-ES@CeO 2-δ -SS), was measured in 1 M HCl, at a common scan rate of 20 mV s −1 . The high adhesion of PANI with cerium oxide prevents the oxide from its slow dissolution in 1MHCl thus providing the stability of this composite in an acidic solution. The rate of electrochemical oxidation of emeraldine salt into pernigraniline was also found to depend on CeO 2-δ characteristics. © 2019 Elsevier Ltd

Two gold nanorod-polyaniline (Au-PANI) composites with different contents of Au were prepared by two methods. An ex situ method, in the presence of preformed gold nanorods (AuNRs) and in situ one, when an AuNRs and PANI matrix is produced simultaneously, were used. Both methods were performed in immiscible water/toluene biphasic system as a simple interfacial polymerization process. Optical, structural and morphological characteristics of the formed nanocomposites were identified. It was found that AuNRs are embedded in the conducting emeraldine salt form of PANI. Nanocomposites containing 2.0 and 28.9 wt% of Au were subsequently systematically studied for borohydride oxidation reaction (BOR) for potential application in direct borohydride-peroxide fuel cell (DBPFC). Reaction parameters: number of electrons exchanged, order of reaction and activation energy, were evaluated. Both Au-PANI nanocomposites showed activity for BOR. A laboratory DBPFC was tested reaching specific peak power density of 184 Wg(-1) at 65 degrees C with Au-PANI 1 nanocomposite (containing only 2.0 wt% of Au) as anode.

Three zeolites (A, X and Y) with Ag incorporated in their cages are tested as bifunctional electrocatalysts for direct borohydride fuel cells (DBFCs). Ag zeolites are characterised by XRD, FTIR, nitrogen sorption and SEM, as well as by electrochemical methods. Ag zeolite shows good activity for the anodic reaction, i.e., borohydride oxidation reaction (BOR) in alkaline media, presenting low onset potential and high current densities. BOR kinetic and faradaic parameters at AgY are calculated, with the number of exchanged electrons being 4.3. The BOR at AgY was found to be of 0.6 order with respect to BH4 concentration with an activation energy of 13 kJ mol 1. Regarding ORR, AgX shows the best performance with the highest current densities and good stability over time. A two-electron pathway is observed for ORR at AgX and specific capacitance was calculated to be 5.61 F g 1. The DBFC performance is investigated based on half-cell measurements of the AgY anode and Pt/C cathode

The authors regret errors in the above mentioned article in the equation (2)as well as in the Fig. 10a. In the equation (2)the number 2 was accidently omitted, whereas the values for the x-axis of Fig. 10a were doubled by accident. The authors would like to apologise for any inconvenience caused. The corrected equation (2)and Fig. 10 are shown below. [Formula presented][Figure presented]Fig. 10. a)Galvanostatic charge-discharge curves for Carb-IL at different current densities in 6 M KOH and b)dependence of the discharge specific capacitance of Carb-IL on the number of cycles, at 5 A g −1 . © 2018 Elsevier Ltd

This work shows the potential application of carbon materials prepared by three different ionic liquid-based methods, using 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3], for electrochemical supercapacitors. The effects of [bmim][MeSO3] on morphology, texture and surface chemistry of prepared materials has been explored by SEM/TEM, N2/CO2 adsorption measurements and XPS. The results indicate the possibility of synthesis of carbon materials with tunable physicochemical properties using ionic liquid based methods. The charge storage behavior of all materials was studied in three different pH aqueous electrolytes. The pseudocapacitive and double layer contributions were estimated and discussed from the aspect of the textural changes and the changes of the chemical composition of surface functional groups containing heteroatoms. C[dbnd]O type functional groups, with the contribution of COOH groups, were found to be responsible for a different amount of charge, which could be stored in alkaline and acidic electrolytic solution. The material prepared by direct carbonization of [bmim][MeSO3], showed the best electrochemical performance in alkaline electrolyte with a capacitance of 187 F g−1 at 5 mV s−1 (or 148 F g−1 at 1 A g−1), due to the contribution of both electric-double layer capacitance and pseudocapacitance which arises from oxygen, nitrogen and sulfur functional groups. © 2018 Elsevier Ltd

This work shows the potential application of carbon materials prepared by three different ionic liquid-based methods, using 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3], for electrochemical supercapacitors. The effects of [bmim][MeSO3] on morphology, texture and surface chemistry of prepared materials has been explored by SEM/TEM, N2/CO2 adsorption measurements and XPS. The results indicate the possibility of synthesis of carbon materials with tunable physicochemical properties using ionic liquid based methods. The charge storage behavior of all materials was studied in three different pH aqueous electrolytes. The pseudocapacitive and double layer contributions were estimated and discussed from the aspect of the textural changes and the changes of the chemical composition of surface functional groups containing heteroatoms. C[dbnd]O type functional groups, with the contribution of COOH groups, were found to be responsible for a different amount of charge, which could be stored in alkaline and acidic electrolytic solution. The material prepared by direct carbonization of [bmim][MeSO3], showed the best electrochemical performance in alkaline electrolyte with a capacitance of 187 F g−1 at 5 mV s−1 (or 148 F g−1 at 1 A g−1), due to the contribution of both electric-double layer capacitance and pseudocapacitance which arises from oxygen, nitrogen and sulfur functional groups.

This work shows the potential application of carbon materials prepared by three different ionic liquid-based methods, using 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3], for electrochemical supercapacitors. The effects of [bmim][MeSO3] on morphology, texture and surface chemistry of prepared materials has been explored by SEM/TEM, N2/CO2 adsorption measurements and XPS. The results indicate the possibility of synthesis of carbon materials with tunable physicochemical properties using ionic liquid based methods. The charge storage behavior of all materials was studied in three different pH aqueous electrolytes. The pseudocapacitive and double layer contributions were estimated and discussed from the aspect of the textural changes and the changes of the chemical composition of surface functional groups containing heteroatoms. C[dbnd]O type functional groups, with the contribution of COOH groups, were found to be responsible for a different amount of charge, which could be stored in alkaline and acidic electrolytic solution. The material prepared by direct carbonization of [bmim][MeSO3], showed the best electrochemical performance in alkaline electrolyte with a capacitance of 187 F g−1 at 5 mV s−1 (or 148 F g−1 at 1 A g−1), due to the contribution of both electric-double layer capacitance and pseudocapacitance which arises from oxygen, nitrogen and sulfur functional groups. © 2018 Elsevier Ltd

Two gold nanorod-polyaniline (Au-PANI) composites with different contents of Au were prepared by two methods. An ex situ method, in the presence of preformed gold nanorods (AuNRs) and in situ one, when an AuNRs and PANI matrix is produced simultaneously, were used. Both methods were performed in immiscible water/toluene biphasic system as a simple interfacial polymerization process. Optical, structural and morphological characteristics of the formed nanocomposites were identified. It was found that AuNRs are embedded in the conducting emeraldine salt form of PANI. Nanocomposites containing 2.0 and 28.9 wt% of Au were subsequently systematically studied for borohydride oxidation reaction (BOR) for potential application in direct borohydride-peroxide fuel cell (DBPFC). Reaction parameters: number of electrons exchanged, order of reaction and activation energy, were evaluated. Both Au-PANI nanocomposites showed activity for BOR. A laboratory DBPFC was tested reaching specific peak power density of 184 Wg(-1) at 65 degrees C with Au-PANI 1 nanocomposite (containing only 2.0 wt% of Au) as anode.

The authors regret errors in the above mentioned article in the equation (2)as well as in the Fig. 10a. In the equation (2)the number 2 was accidently omitted, whereas the values for the x-axis of Fig. 10a were doubled by accident. The authors would like to apologise for any inconvenience caused. The corrected equation (2)and Fig. 10 are shown below. [Formula presented][Figure presented]Fig. 10. a)Galvanostatic charge-discharge curves for Carb-IL at different current densities in 6 M KOH and b)dependence of the discharge specific capacitance of Carb-IL on the number of cycles, at 5 A g −1 . © 2018 Elsevier Ltd

Three zeolites (A, X and Y) with Ag incorporated in their cages are tested as bifunctional electrocatalysts for direct borohydride fuel cells (DBFCs). Ag zeolites are characterised by XRD, FTIR, nitrogen sorption and SEM, as well as by electrochemical methods. Ag zeolite shows good activity for the anodic reaction, i.e., borohydride oxidation reaction (BOR) in alkaline media, presenting low onset potential and high current densities. BOR kinetic and faradaic parameters at AgY are calculated, with the number of exchanged electrons being 4.3. The BOR at AgY was found to be of 0.6 order with respect to BH4 concentration with an activation energy of 13 kJ mol 1. Regarding ORR, AgX shows the best performance with the highest current densities and good stability over time. A two-electron pathway is observed for ORR at AgX and specific capacitance was calculated to be 5.61 F g 1. The DBFC performance is investigated based on half-cell measurements of the AgY anode and Pt/C cathode

This work shows the potential application of carbon materials prepared by three different ionic liquid-based methods, using 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3], for electrochemical supercapacitors. The effects of [bmim][MeSO3] on morphology, texture and surface chemistry of prepared materials has been explored by SEM/TEM, N2/CO2 adsorption measurements and XPS. The results indicate the possibility of synthesis of carbon materials with tunable physicochemical properties using ionic liquid based methods. The charge storage behavior of all materials was studied in three different pH aqueous electrolytes. The pseudocapacitive and double layer contributions were estimated and discussed from the aspect of the textural changes and the changes of the chemical composition of surface functional groups containing heteroatoms. C[dbnd]O type functional groups, with the contribution of COOH groups, were found to be responsible for a different amount of charge, which could be stored in alkaline and acidic electrolytic solution. The material prepared by direct carbonization of [bmim][MeSO3], showed the best electrochemical performance in alkaline electrolyte with a capacitance of 187 F g−1 at 5 mV s−1 (or 148 F g−1 at 1 A g−1), due to the contribution of both electric-double layer capacitance and pseudocapacitance which arises from oxygen, nitrogen and sulfur functional groups.

У складу са чињеницом да се све више пажње посвећује коришћењу обновљивих извора енергије, па тако и могућностима употребе дрвне биомасе као еколошки прихватљивом гориву, али и ресурсу који може бити употребљен у другим индустријама (индустрија целулозе и папира, индустрија плоча и иверица), у овом раду је истражен производни потенцијал дрвне биомасе (дрвне сечке) и његов утицај на циљеве газдовања шумама у Јужнобачком шумском подручју. У раду су испитани механизми припреме и доношења одлука, који подразумевају „анализу предузећа“ и „анализу окружења“ уз укључивање интересних група и усклађивање потреба и визија са могућностима производње дрвне биомасе. Доношење одлука се односи на избор најбољег плана газдовања шумама у односу на постављени проблем одлучивања. Примењени су формирани модели одлучивања за потребе рангирања и избора најбољег плана газдовања шумама у односу на постављене захтеве (производња дрвне биомасе). Приликом избора најбољег алтернативног плана газдовања шумама неопходно је било одредити приоритете између појединих алтернатива или критеријума у ситуацијама одлучивања где учествује један, али и већи број доносилаца одлука и где је присутан већи број критеријума одлучивања у вишеструким временским периодима. Доношењу одлука су претходили конфликтни услови и за решавање оваквих задатака морале су бити примењенe научне методе које су флексибилније од строго математичких метода чисте оптимизације, као што су линеарно програмирање, динамичко програмирање или теорија игара. У овако конфликтној ситуацији неопходно је било направити избор оптималног односа елемената који сачињавају план газдовања шумама (оцена фактора који утичу на дефинисање и рангирање циљева газдовања шумама) са аспекта могућности производње дрвне биомасе. Метода АХП је изабрана због чињенице да циљ овог рада захтева неку врсту оптимизације шуме као сложеног природно еколошко-економског система према коме се константно увећавају захтеви друштва (у овом раду биомаса као нови производ)., As renewable energy sources are gaining ever more importance, the same happens with the possibilities of using woody biomass as an environmentally friendly fuel, but also a resource that can be used in other industries (pulp and paper industry, board and chipboard industry). This study investigates the production potential of woody biomass (wood chips) and its impact on forest management goals in the South Bačka forest area. The thesis examines the mechanisms of preparation and decision-making, which include "enterprise analysis" and "analysis of the environment" with the involvement of stakeholder groups and harmonization of needs and visions with the economic possibilities of woody biomass production. The decision-making refers to the selection of the best forest management plan in relation to the problem of decision-making. The formed models of decision-making were applied for the needs of ranking and selection of the best forest management plan in relation to the imposed requirements (production of woody biomass). When choosing the best alternative forest management plan, it was necessary to determine the priorities between certain alternatives or criteria in decision-making situations involving one, but also a larger number of decision-makers, and where a number of decision-making criteria are present in multiple time periods. Decision-making was preceded by conflicting conditions for solving such tasks. Instruments that were more flexible than strictly mathematical techniques of pure optimization, such as linear programming, dynamic programming, or game theory, had to be applied. In this case, it was necessary to select the optimal ratio of the elements that constitute the forest management plan (assessment of factors that influence the definition and ranking of forest management goals) from the aspect of the possibility of producing woody biomass. This method was chosen because of the fact that the aim of this thesis requires some kind of optimization of the

Carbon materials, prepared by using different methods with ionicliquids, are compared as electrocatalysts for the oxygen reductionreaction (ORR). Materials were synthesized through the hydrothermalcarbonization of glucose and by using the same method in the presence of1-butyl-3-methylimidazolium methanesulfonate {[}bmim]{[}MeSO3] as anadditive. Another two carbon-based materials were prepared by usingionic-liquid-based methods: ionothermal carbonization of glucose using{[}bmim]{[}MeSO3] as a recyclable medium for the carbonization reactionand by direct carbonization of the ionic liquid in a one-step methodusing {[}bmim]{[}MeSO3] as the precursor for N- and S-doped porouscarbon (Carb-IL). Characterization results showed the possibility ofmorphology and porosity control by using {[}bmim]{[}MeSO3]. Allmaterials were subsequently tested for the ORR in alkaline media.Carb-IL showed enhanced and stable electrocatalytic ORR activity, evenin the presence of methanol, ethanol, and borohydride, opening thepossibility for its application in fuel cells.

Carbon materials, prepared by using different methods with ionicliquids, are compared as electrocatalysts for the oxygen reductionreaction (ORR). Materials were synthesized through the hydrothermalcarbonization of glucose and by using the same method in the presence of1-butyl-3-methylimidazolium methanesulfonate {[}bmim]{[}MeSO3] as anadditive. Another two carbon-based materials were prepared by usingionic-liquid-based methods: ionothermal carbonization of glucose using{[}bmim]{[}MeSO3] as a recyclable medium for the carbonization reactionand by direct carbonization of the ionic liquid in a one-step methodusing {[}bmim]{[}MeSO3] as the precursor for N- and S-doped porouscarbon (Carb-IL). Characterization results showed the possibility ofmorphology and porosity control by using {[}bmim]{[}MeSO3]. Allmaterials were subsequently tested for the ORR in alkaline media.Carb-IL showed enhanced and stable electrocatalytic ORR activity, evenin the presence of methanol, ethanol, and borohydride, opening thepossibility for its application in fuel cells.

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.

NiA and NiX zeolites were prepared and characterised using XRD, FTIR and SEM, and subsequently tested as electrodes for hydrogen (HER) and oxygen (OER) evolution reactions in alkaline media. Linear sweep voltammetry and chronoamperometry techniques showed that NiA has higher catalytic activity for these two reactions, as evidenced by higher current densities, which can be correlated with a higher weight fraction of Ni in this electrocatalyst than in the NiX and with its higher conductivity. HER and OER kinetic parameters, including Tafel slope, exchange current density and apparent activation energy were evaluated. Electrochemical impedance spectroscopy analysis yielded values of the resistance of the solution, charge transfer and mass transfer, as well as double layer capacitance and pseudo-capacitance of the working electrode, at different potentials and temperatures. Unlike the HER, during which the mass transfer resistance of the adsorbed intermediate is dominant in the case of NiA, the OER impedance response is controlled by the charge transfer process itself at the potentials of interest for these process. The overall resistance related to the HER is lower for NiA than for NiX. © 2018 Hydrogen Energy Publications LLC

NiA and NiX zeolites were prepared and characterised using XRD, FTIR and SEM, and subsequently tested as electrodes for hydrogen (HER) and oxygen (OER) evolution reactions in alkaline media. Linear sweep voltammetry and chronoamperometry techniques showed that NiA has higher catalytic activity for these two reactions, as evidenced by higher current densities, which can be correlated with a higher weight fraction of Ni in this electrocatalyst than in the NiX and with its higher conductivity. HER and OER kinetic parameters, including Tafel slope, exchange current density and apparent activation energy were evaluated. Electrochemical impedance spectroscopy analysis yielded values of the resistance of the solution, charge transfer and mass transfer, as well as double layer capacitance and pseudo-capacitance of the working electrode, at different potentials and temperatures. Unlike the HER, during which the mass transfer resistance of the adsorbed intermediate is dominant in the case of NiA, the OER impedance response is controlled by the charge transfer process itself at the potentials of interest for these process. The overall resistance related to the HER is lower for NiA than for NiX. © 2018 Hydrogen Energy Publications LLC

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.

NiA and NiX zeolites were prepared and characterised using XRD, FTIR and SEM, and subsequently tested as electrodes for hydrogen (HER) and oxygen (OER) evolution reactions in alkaline media. Linear sweep voltammetry and chronoamperometry techniques showed that NiA has higher catalytic activity for these two reactions, as evidenced by higher current densities, which can be correlated with a higher weight fraction of Ni in this electrocatalyst than in the NiX and with its higher conductivity. HER and OER kinetic parameters, including Tafel slope, exchange current density and apparent activation energy were evaluated. Electrochemical impedance spectroscopy analysis yielded values of the resistance of the solution, charge transfer and mass transfer, as well as double layer capacitance and pseudo-capacitance of the working electrode, at different potentials and temperatures. Unlike the HER, during which the mass transfer resistance of the adsorbed intermediate is dominant in the case of NiA, the OER impedance response is controlled by the charge transfer process itself at the potentials of interest for these process. The overall resistance related to the HER is lower for NiA than for NiX. © 2018 Hydrogen Energy Publications LLC

NiA and NiX zeolites were prepared and characterised using XRD, FTIR and SEM, and subsequently tested as electrodes for hydrogen (HER) and oxygen (OER) evolution reactions in alkaline media. Linear sweep voltammetry and chronoamperometry techniques showed that NiA has higher catalytic activity for these two reactions, as evidenced by higher current densities, which can be correlated with a higher weight fraction of Ni in this electrocatalyst than in the NiX and with its higher conductivity. HER and OER kinetic parameters, including Tafel slope, exchange current density and apparent activation energy were evaluated. Electrochemical impedance spectroscopy analysis yielded values of the resistance of the solution, charge transfer and mass transfer, as well as double layer capacitance and pseudo-capacitance of the working electrode, at different potentials and temperatures. Unlike the HER, during which the mass transfer resistance of the adsorbed intermediate is dominant in the case of NiA, the OER impedance response is controlled by the charge transfer process itself at the potentials of interest for these process. The overall resistance related to the HER is lower for NiA than for NiX. © 2018 Hydrogen Energy Publications LLC

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.

Carbon materials, prepared by using different methods with ionicliquids, are compared as electrocatalysts for the oxygen reductionreaction (ORR). Materials were synthesized through the hydrothermalcarbonization of glucose and by using the same method in the presence of1-butyl-3-methylimidazolium methanesulfonate {[}bmim]{[}MeSO3] as anadditive. Another two carbon-based materials were prepared by usingionic-liquid-based methods: ionothermal carbonization of glucose using{[}bmim]{[}MeSO3] as a recyclable medium for the carbonization reactionand by direct carbonization of the ionic liquid in a one-step methodusing {[}bmim]{[}MeSO3] as the precursor for N- and S-doped porouscarbon (Carb-IL). Characterization results showed the possibility ofmorphology and porosity control by using {[}bmim]{[}MeSO3]. Allmaterials were subsequently tested for the ORR in alkaline media.Carb-IL showed enhanced and stable electrocatalytic ORR activity, evenin the presence of methanol, ethanol, and borohydride, opening thepossibility for its application in fuel cells.

Palladium ion-exchanged zeolite X (PdX) was prepared by zeolite impregnation with palladium acetylacetonate, followed by thermal degradation of the salt. PdX was characterised using SEM-EDS, ICP-OES and XRD. Analysis revealed presence of 7.78 wt.% of Pd in the form of PdO. Subsequently, PdX was tested for hydrogen evolution reaction (HER) in alkaline medium using linear scan voltammetry, chronoamperometry and electrochemical impedance spectroscopy measurements. The influence of addition of carbon black on the materials catalytic performance was also investigated. The HER kinetic parameters, including Tafel slope, exchange current density and activation energy, were determined. In order to provide atomic-level insights, experimental results were complemented by density functional theory calculations. It is suggested that favourable hydrogen adsorption energetics on PdO is responsible for efficient HER catalysis by this novel electrocatalyst. (c) 2017 Elsevier Ltd. All rights reserved.

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.

Carbon materials, prepared by using different methods with ionic liquids, are compared as electrocatalysts for the oxygen reduction reaction (ORR). Materials were synthesized through the hydrothermal carbonization of glucose and by using the same method in the presence of 1-butyl-3-methylimidazolium methanesulfonate [bmim][MeSO3] as an additive. Another two carbon-based materials were prepared by using ionic-liquid-based methods: ionothermal carbonization of glucose using [bmim][MeSO3] as a recyclable medium for the carbonization reaction and by direct carbonization of the ionic liquid in a one-step method using [bmim][MeSO3] as the precursor for N- and S-doped porous carbon (Carb-IL). Characterization results showed the possibility of morphology and porosity control by using [bmim][MeSO3]. All materials were subsequently tested for the ORR in alkaline media. Carb-IL showed enhanced and stable electrocatalytic ORR activity, even in the presence of methanol, ethanol, and borohydride, opening the possibility for its application in fuel cells.