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The growing energy crisis put an emphasis on the development of novel efficient energy conversion and storage systems. Here we show that surface modification of cobalt by a fast galvanic displacement with rhodium significantly affects the activity towards hydrogen (HER) and oxygen evolution reactions (OER) in alkaline media. After only 20 s of galvanic displacement, the HER overpotential is reduced by 0.16 V and OER overpotential by 0.06 V. This means that the predicted water splitting voltage is reduced from 2.03 V (clean Co anode and cathode) to 1.81 V at 10 mA cm−2 (Rh-exchanged Co electrode). During the galvanic displacement process, the surface roughness of the Co electrode does not suffer significant changes, which suggests an increase in the intrinsic catalytic activity. Density Functional Theory calculations show that the reactivity of the Rh-modified Co(0001) surface is modified compared to that of the clean Co(0001). In the case of HER, experimentally observed activity improvements are directly correlated to the weakening of the hydrogen-surface bond, confirming the beneficial role of Rh incorporation into the Co surface. Graphical abstract: [Figure not available: see fulltext.]., QC 20230721

Herein we unequivocally identify the mechanism of zeolite-catalysed thermal degradation of pesticide, employing Fourier-transform infrared spectroscopy (FTIR), Raman and mass spectrometry following temperature decomposition (TPDe/MS). We demonstrate that Y zeolite can effectively adsorb a significant amount of acetamiprid both in a single trial (168 mg/g) and in 10 cycles (1249 mg/g) with intermittent thermal regeneration at 300 °C. Sectional vibrational analysis of acetamiprid two-stage thermal degradation is performed for pristine and supported pesticide. The acetamiprid Raman spectral changes appear at 200 °C, while partial carbonization occurs at 250 °C. The gradual disappearance of the FTIR bands of acetamiprid is seen up to 270 °C when two Raman signature bands for carbonised material emerged. The TPDe/MS profiles reveal the evolution of mass fragments - in the first step, cleavage of the C[sbnd]C bond occurs between the aromatic core of the molecule and its tail-end, followed by cleavage of the C[sbnd]N bond. The mechanism of adsorbed acetamiprid degradation follows the same step, at significantly lower temperatures, as the process is catalysed by the interaction of acetamiprid nitrogens and zeolite support. Reduced temperature degradation allows for a quick recovery process that leaves 65% efficacy after 10 cycles. After numerous cycles of recovery, a subsequent one-time heat treatment at 700 °C completely restores initial efficacy. The efficient adsorption, novel details on degradation mechanism and ease of regeneration procedure place the Y zeolite at the forefront of future all-encompassing environmental solutions.

Composites of carbons with metal oxides and metal sulfides have attracted a lot of interestas materials for energy conversion and storage applications. Herein, we report on novel N,O-dopedcarbon/ZnO/ZnS and N,O-doped carbon/ZnO composites (generally named C-(MOF-5/PANI)),synthesized by the carbonization of metal–organic framework MOF-5/polyaniline (PANI) composites.The produced C-(MOF-5/PANI)s are comprehensively characterized in terms of composition,molecular and crystalline structure, morphology, electrical conductivity, surface area, and electrochemicalbehavior. The composition and properties of C-(MOF-5/PANI) composites are dictated bythe composition of MOF-5/PANI precursors and the form of PANI (conducting emeraldine salt (ES)or nonconducting emeraldine base). The ZnS phase is formed only with the PANI-ES form due toS-containing counter-ions. XRPD revealed that ZnO and ZnS existed as pure wurtzite crystallinephases. PANI and MOF-5 acted synergistically to produce C-(MOF-5/PANI)s with high SBET (up to609 m2 g−1), electrical conductivity (up to 0.24 S cm−1), and specific capacitance, Cspec, (up to 238.2 Fg−1 at 10 mV s−1). Values of Cspec commensurated with N content in C-(MOF-5/PANI) composites (1–10 wt.%) and overcame Cspec of carbonized individual components PANI and MOF-5. By acid etchingtreatment of C-(MOF-5/PANI), SBET and Cspec increased to 1148 m2 g−1 and 341 F g−1, respectively.The developed composites represent promising electrode materials for supercapacitors.

Composites of carbons with metal oxides and metal sulfides have attracted a lot of interest as materials for energy conversion and storage applications. Herein, we report on novel N,O-doped carbon/ZnO/ZnS and N,O-doped carbon/ZnO composites (generally named C-(MOF-5/PANI)), synthesized by the carbonization of metal–organic framework MOF-5/polyaniline (PANI) composites. The produced C-(MOF-5/PANI)s are comprehensively characterized in terms of composition, molecular and crystalline structure, morphology, electrical conductivity, surface area, and electrochemical behavior. The composition and properties of C-(MOF-5/PANI) composites are dictated by the composition of MOF-5/PANI precursors and the form of PANI (conducting emeraldine salt (ES) or nonconducting emeraldine base). The ZnS phase is formed only with the PANI-ES form due to S-containing counter-ions. XRPD revealed that ZnO and ZnS existed as pure wurtzite crystalline phases. PANI and MOF-5 acted synergistically to produce C-(MOF-5/PANI)s with high SBET (up to 609 m2 g−1), electrical conductivity (up to 0.24 S cm−1), and specific capacitance, Cspec, (up to 238.2 F g−1 at 10 mV s−1). Values of Cspec commensurated with N content in C-(MOF-5/PANI) composites (1– 10 wt.%) and overcame Cspec of carbonized individual components PANI and MOF-5. By acid etching treatment of C-(MOF-5/PANI), SBET and Cspec increased to 1148 m2 g−1 and 341 F g−1, respectively. The developed composites represent promising electrode materials for supercapacitors.

All remediation pathways in aqueous solutions come down to three dominant ones - physical, chemical, and combinations thereof. Materials proposed for adsorption and oxidative degradation can induce positive or negative effects on cells compared to the pollutants themselves. Present research deals with the effects different methods for pesticide remediation have and how they impact cytotoxicity. With this particular intention, Fe-modified zeolites (obtained via citrate/oxalate complexes) of three zeotypes (MFI, BEA and FAU) were prepared and tested as adsorbents and Fenton catalysts for the removal of the acetamiprid pesticide. The materials are characterized by AFM, FTIR spectroscopy and ICP-OES. A different effect of the zeolite framework and modification route was found among the samples, which leads to pronounced adsorption (FAU), efficient Fenton degradation (MFI) or synergistic effect of both mechanisms (BEA). The cytotoxic effects of acetamiprid in the presence of zeolites, in pristine and modified forms, were tested on the MRC-5 human fibroblast cell line. A complete survey of the toxicity effect behind different pesticide removal methods is presented. Since neither adsorption nor catalytic degradation is the best option for pesticide removal, the focus is shifted to a combination of these methods, which proved to be optimal for pesticide toxicity reduction.

Ecotoxicity caused by neonicotinoid pesticides is largely due to oxidative stress on non-target species. Due to the fact that reactive radical species reach the environment, materials intended for pesticide removal should be applicable for the simultaneous removal of reactive radicals, as well. This work uses the spectroscopic, adsorptive and antioxidant responses from MFI, FAU and BEA zeolites as descriptors of their potential environmental importance. Different network structures and Si/Al ratios were correlated with excellent zeolite adsorption properties, as over 200 mg g1 of investigated neonicotinoids, acetamiprid and imidacloprid, was achieved in one cycle. Additionally, after two regeneration steps, over 450 mg g1 adsorbed pesticides were retained, in three adsorption cycles. Overall the best results were detected for the FAU zeotype in both tested applications, insecticide adsorption and radical-scavenging performance, with and without insecticides present. The proposed mechanism for adsorption relies on kinetic investigation, isotherm modelling and spectroscopic post-adsorption analysis and targets zeolite hydroxyl/siloxane groups as active sites for insecticide adsorption via hydrogen bonding. Neat, welldefined zeolite structures enable their prospective application in ecotoxic species removal.

Environmentaly friendly photoelectrochemical (PEC) materals are in the center of the research interest for sustainable solar-to-chemical energy conversion. Lately, bismuth vanadate (BiVO4) has attracted attention due to its visible light harvesting properties, band edge positions and lowcost synthesis method. However, BiVO4 has poor charge transfer properties due to the high rate of electron-hole recombination. It has been shown that metal doping efficiently boosts charge separation and hence increases PEC water splitting activity. Herein, we report physicochemical properties of hydrothermaly sinthesized 1%-, 2.5%- and 5%- Cu-doped BiVO4 powders for 8 h and 20 h. X-ray diffraction (XRD) study indicates that, depending on the degree of doping and synthesis time, material exists in monoclinic or tetragonal scheelite phase, but mixed phase composition was also possible. Monoclinic phase was formed in a case of pristine samples (synthesized for 8 h and 20 h) and 1% and 2.5% doped samples synthesized for 8 h. Tetragonal phase was observed in case of 5% and 1% doped samples synthesized for 8 h and 20 h, respectively. In the samples synthesized for 20 h and doped with 2.5% and 5% mixed phase was noticed. Scanning electron microscopy (SEM) reveals that samples with monoclinic phase consists of combination of worm-like and prismatic structures while tetragonal samples showed spherical shape. In case of samples with mixed phase a combination of prismatic and spherical shape was observed. Local structure was examined with Raman and Fourier Transformed Infrared (FTIR) spectroscopy. Optical properties were characterized with UV-Vis Diffuse Reflectance Spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. Monoclinic phase has band gap in range 2.35 – 2.52 eV while samples with tetragonal phase has band gap in range 2.8 – 3 eV. Based on the results it can be concluded that band gap is dependent on the phase composition of samples. PL results indicate that monoclinic samples

Production of gasses such as hydrogen and oxygen on a large scale is of the great importance both in industry and in environmental protection. To achieve it, photoelectrochemical (PEC) water splitting has been regarded as promising method and the developement of new semiconductors holds a key role to the efficent application. Due to its great light harvesting ability, band edge positions and low-cost synthesis method, bismuth vanadate (BiVO4; BVO) has been intensively studied as a photoanode material for water splitting. To overcome limitations such as charge carriers recombination, material should be doped with different transition metal elements. In this work physicochemical properties of pristine and 1%-, 2.5%- and 5%- Cu-doped BVO powders, solvothermaly synthesized at 180°C for 20 h, were reported. X-ray diffraction (XRD) study indicates that, depending on the doping level, the material exists in monoclinic or tetragonal scheelite phase, but mixed phase composition was also observed. Pure monoclinic and tetragonal phase was formed in a case of pristine and 1% doped sample, respectively, while 2.5%- and 5%- Cu-doped BVO exhibit presence of both phases. Scanning electron microscopy (SEM) reveals that sample with monoclinic phase consists of irregular worm-like morphology, while morphology of tetragonal samples was mostly spherical. For 2.5%- and 5%- Cu-doped samples a combination of prismatic and spherical shape morphology was observed. Local structure of material was examined with Raman spectroscopy and the results were in accordance with XRD study where band positions well matched the phase composition. Optical properties were characterized with UV-Vis Diffuse Reflectance Spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. The band gap of monoclinic samples was in range 2.4-2.5 eV, while band gap of sample with tetragonal phase has band gap was between 2.8 and 3 eV. Dual phase samples had two different band gaps that originate from presence of both phase

All remediation pathways in aqueous solutions come down to three dominant ones - physical, chemical, and combinations thereof. Materials proposed for adsorption and oxidative degradation can induce positive or negative effects on cells compared to the pollutants themselves. Present research deals with the effects different methods for pesticide remediation have and how they impact cytotoxicity. With this particular intention, Fe-modified zeolites (obtained via citrate/oxalate complexes) of three zeotypes (MFI, BEA and FAU) were prepared and tested as adsorbents and Fenton catalysts for the removal of the acetamiprid pesticide. The materials are characterized by AFM, FTIR spectroscopy and ICP-OES. A different effect of the zeolite framework and modification route was found among the samples, which leads to pronounced adsorption (FAU), efficient Fenton degradation (MFI) or synergistic effect of both mechanisms (BEA). The cytotoxic effects of acetamiprid in the presence of zeolites, in pristine and modified forms, were tested on the MRC-5 human fibroblast cell line. A complete survey of the toxicity effect behind different pesticide removal methods is presented. Since neither adsorption nor catalytic degradation is the best option for pesticide removal, the focus is shifted to a combination of these methods, which proved to be optimal for pesticide toxicity reduction.

Heteropolyacids and their salts comprise catalytic centers for the production of ethylene, one of the most important constituents in the chemical industry. The paper emphasizes different synthesis routes of hybrid materials consisting of dodecatungstophosphoric acid silver salt (AgPW) and β zeolite—stepwise wet impregnation, silver-exchange in β zeolite, and dry mixing of precursors. Composite preparation procedures induced minor effects on the weak acid sites, while strong acid sites were increased significantly. β/AgPW composites prepared by two-steps wet impregnation and ion-exchange procedures have strong acid sites content and total acidity higher in comparison to the pure AgPW salt and β zeolite. This is a result of precursors synergetic effect—cumulative strong acidic sites are generated in the presence of well-dispersed Keggin ions on the zeolite network. Composite samples with a higher content of strong acid centers exhibit higher conversion in the ethanol dehydration reaction, i.e., the ion-exchanged βAgPW sample has attained a conversion over 81%, while the wet-impregnated sample has a significant 86%. The distribution and presence of AgPW active phase are found to be crucial for both stable conversion and high selectivity results in ethylene production from ethanol, which is regarded as one of the most significant processes in environmental and sustainable industrial chemistry. Graphic abstract: [Figure not available: see fulltext.]

Composite materials consisting of the silver salt of dodecatungstophosphoric acid and HBEA zeolite are developed in order to give materials of superior adsorption properties for aqueous pesticide removal. Two-step impregnation and an ion-exchange method with variable constituent mass ratios were employed as synthesis procedures. One of the study goals was to optimize the composite preparation for efficient elimination of glyphosate pesticide and to investigate the modulation of antioxidant activity in the presence of pesticide. Based on comprehensive results, we propose mechanisms for simultaneous glyphosate removal and antioxidant activity. Spectroscopic analysis shows that the applied two-step impregnation method results in advanced composite materials with evenly distributed active sites for glyphosate adsorption and radical-scavenging activity. The original Krishnamurti isotherm is successfully used to fit pesticide adsorption data, pointing to co-operative adsorption of glyphosate on partly saturated adsorbents sites. The amount of glyphosate adsorbed from water suspension was 378 mg per gram of composite material, the highest value reported for glyphosate removal to date.

Environmental implementation of novel composite materials comprising potassium tungstophosphate (KPW) and ZSM-5 zeolite was tested in ethene production and pesticide removal. The study revealed that the binding of KPW to ZSM-5 zeolites of different Si/Al ratios affects the formation of active centres for catalytic and adsorption processes. Brønsted active sites present in the zeolite framework are synergistically joined with Lewis centres and additional Brønsted centres through the impregnation of potassium tungstophosphate, which resulted in improvement of stability and activity of investigated materials. Adsorption and catalytic performance were found to be influenced by the order of addition of salt precursors and by post-synthesis thermal treatment. The best results found both in ethanol dehydration and nicosulfuron removal were for the same sample of KPW supported at zeolite ZSM-5 (SiO2/Al2O3 = 30). The prominent ethanol conversion of 98% and the highest and most stable selectivity toward ethene were evidenced, along with the capacity of 28.4 mg of targeted pesticide retained per gram of designed KPW/ZSM composite. This comprehensive investigation enabled insight into active site formations in the efficient KPW/ZSM composites. Different approaches to implementation revealed that a lower Si/Al ratio in zeolite promotes efficient K+ exchange, which combined with two-phased in situ preparation of KPW as active phase, evidently leads to the formation of isolated sites of superior activity for both catalytic and adsorptive procedures.

The oscillatory Briggs‐Rauscher (BR) reaction was applied on solid insoluble materials i. e. bentonite clays. Under the same BR experimental conditions, the addition of identical masses of bentonite of different origin resulted in different effects on oscillatory time duration (τ): no influence, quenching, or prolongation. It was found that the following bentonite properties: montmorillonite/beidellite ratio; cation exchange capacity; principal exchange cation; extent of iron leaching in acidic environment of BR reaction; and specific surface area of clay were not exclusively responsible for observed behavior. On the other hand, the influence of added mass, for all investigated clays, resulted in the same behavior pattern. The increase of the mass of added clay increased τ up to the certain maximal value (τmax, mmax) characteristic for each clay. Further increase of mass resulted in quenching. Therefore, (τmax, mmax) pair can be regarded as the “fingerprint” characteristic of bentonite useful for identification of its origin. Furthermore, the addition of naturally occurring and non‐toxic clay in an oscillatory reaction can offer a versatile approach to tune the oscillation dynamics of nonlinear chemical systems.

Novel composites of BEA zeolite and silver tungstophosphate were prepared by different procedures: two-step impregnation, ion-exchange, and as physical mixtures with varying component mass ratios. Composites were characterized using Atomic force microscopy, Infrared, Raman and Atomic absorption spectroscopy, and results were related to adsorption properties and antimicrobial efficiencies of the composites. Prepared samples were tested as antimicrobial agents for fungal and different bacterial strains, as well as for adsorbents for pesticide nicosulfuron in aqueous solutions by using High-performance liquid chromatography. Experimental conditions for batch adsorption testing were optimized in order to efficiently eliminate nicosulfuron from aqueous solutions, while enabling antimicrobial activity of these advanced materials. Antimicrobial efficiency of composites was verified, and indicated that silver ion persistence in the solid phase is of utmost significance for the antimicrobial activity. Spectroscopic investigation revealed interaction of the silver tungstophosphate active phase and the zeolite framework, giving evidence of uniform distribution of active sites in the synthesized materials that proved to be essential for adsorption application. The best obtained adsorption capacity, as well as highest antimicrobial efficiency, is found for composite samples prepared by two-step impregnation with (BEA: silver tungstophosphate) mass ratio 2:1. The amount of nicosulfuron removed from water suspension was 38.2 mg per gram of composite, and the minimum inhibitory concentration determined for all investigated gram-negative bacteria was 125 μg mL−1.

Series of alkylammonium modified smectites with different alkylammoinum/clay ratios was synthesized (H series). The obtained organoclays were used as precursors for carbon-clay composite materials (C series). Both set of materials were characterized by X-ray diffraction (XRD), point of zero charge (pH(PZC)), N-2 adsorption-desorption isotherms, Raman spectroscopy and electron paramagnetic resonance (EPR) analysis. XRD analysis of organomodified clays confirmed incorporation of HDTMA(+) into interlamellar space of smectite. Series of carbonized clays showed constant d(001) value of 1.4 nm. The pH(PZC) of two series differed indicating that carbonization changed the profile of pH dependent sites on the clay surface. Textural properties of the H series decreased throughout the series, while in the C series the most developed porous structure was obtained for sample where HDTMA(+) loading was equal to cation exchange capacity. Raman spectroscopy showed that amorphous carbon was formed during carbonization process. The obtained materials were used as modifiers of carbon paste electrode and investigated using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The comparison of electrochemical behavior of H series and C series showed the importance of interlamellar species for charge transfer process. The investigation of influence of composition of carbon paste and form of added carbon showed that performance of carbon-clay based electrodes depended on synergy of different factors.

Series of alkylammonium modified smectites with different alkylammoinum/clay ratios was synthesized (H series). The obtained organoclays were used as precursors for carbon-clay composite materials (C series). Both set of materials were characterized by X-ray diffraction (XRD), point of zero charge (pH(PZC)), N-2 adsorption-desorption isotherms, Raman spectroscopy and electron paramagnetic resonance (EPR) analysis. XRD analysis of organomodified clays confirmed incorporation of HDTMA(+) into interlamellar space of smectite. Series of carbonized clays showed constant d(001) value of 1.4 nm. The pH(PZC) of two series differed indicating that carbonization changed the profile of pH dependent sites on the clay surface. Textural properties of the H series decreased throughout the series, while in the C series the most developed porous structure was obtained for sample where HDTMA(+) loading was equal to cation exchange capacity. Raman spectroscopy showed that amorphous carbon was formed during carbonization process. The obtained materials were used as modifiers of carbon paste electrode and investigated using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The comparison of electrochemical behavior of H series and C series showed the importance of interlamellar species for charge transfer process. The investigation of influence of composition of carbon paste and form of added carbon showed that performance of carbon-clay based electrodes depended on synergy of different factors.

Potassium tungstophosphate is supported on BEA zeolite by in situ synthesis for glyphosate removal. Spectroscopic measurements identified hydrogen bonding as a primal interaction of potassium salt and BEA zeolite. Composites are evaluated for glyphosate herbicide removal and adsorption process is analyzed using two isotherm models. Obtained adsorption capacities for all prepared composites lay between 45.2 and 92.2 mg of glyphosate per gram of investigated composite. Suspension acidity revealed that glyphosate is adsorbed mainly in the zwitter-ion form at the composite surface while the amount of potassium salt in the composites is crucial for the adsorption application. Exceptional adsorption behavior is postulated to come from a high degree of homogeneity among surface active sites which is confirmed by different experimental methods. Temperature programmed desorption of glyphosate coupled with mass spectrometer detected one broad, high-temperature peak which represents overlapped desorption processes from active sights of similar strength. Introduction of potassium tungstophosphate affects active sites present in BEA zeolite for glyphosate desorption and significantly increases the amount of adsorbed pesticide in comparison to BEA zeolite. Supporting of potassium tungstophosphate on BEA zeolite via in situ synthesis procedure enables the formation of highly efficient adsorbents and revealed their perspective environmental application.

Series of alkylammonium modified smectites with different alkylammoinum/clay ratios was synthesized (H series). The obtained organoclays were used as precursors for carbon-clay composite materials (C series). Both set of materials were characterized by X-ray diffraction (XRD), point of zero charge (pH(PZC)), N-2 adsorption-desorption isotherms, Raman spectroscopy and electron paramagnetic resonance (EPR) analysis. XRD analysis of organomodified clays confirmed incorporation of HDTMA(+) into interlamellar space of smectite. Series of carbonized clays showed constant d(001) value of 1.4 nm. The pH(PZC) of two series differed indicating that carbonization changed the profile of pH dependent sites on the clay surface. Textural properties of the H series decreased throughout the series, while in the C series the most developed porous structure was obtained for sample where HDTMA(+) loading was equal to cation exchange capacity. Raman spectroscopy showed that amorphous carbon was formed during carbonization process. The obtained materials were used as modifiers of carbon paste electrode and investigated using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The comparison of electrochemical behavior of H series and C series showed the importance of interlamellar species for charge transfer process. The investigation of influence of composition of carbon paste and form of added carbon showed that performance of carbon-clay based electrodes depended on synergy of different factors.

Series of alkylammonium modified smectites with different alkylammoinum/clay ratios was synthesized (H series). The obtained organoclays were used as precursors for carbon-clay composite materials (C series). Both set of materials were characterized by X-ray diffraction (XRD), point of zero charge (pH(PZC)), N-2 adsorption-desorption isotherms, Raman spectroscopy and electron paramagnetic resonance (EPR) analysis. XRD analysis of organomodified clays confirmed incorporation of HDTMA(+) into interlamellar space of smectite. Series of carbonized clays showed constant d(001) value of 1.4 nm. The pH(PZC) of two series differed indicating that carbonization changed the profile of pH dependent sites on the clay surface. Textural properties of the H series decreased throughout the series, while in the C series the most developed porous structure was obtained for sample where HDTMA(+) loading was equal to cation exchange capacity. Raman spectroscopy showed that amorphous carbon was formed during carbonization process. The obtained materials were used as modifiers of carbon paste electrode and investigated using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The comparison of electrochemical behavior of H series and C series showed the importance of interlamellar species for charge transfer process. The investigation of influence of composition of carbon paste and form of added carbon showed that performance of carbon-clay based electrodes depended on synergy of different factors.

Refined diatomite from the Kolubara coal basin (Serbia) was inorganically functionalized through a simple, one-pot, non-time-consuming procedure. Model drug ibuprofen was adsorbed on the functionalized diatomite under optimized conditions providing high drug Loading (similar to 201 mg g(-1)). Physicochemical characterization was performed on the starting and modified diatomite before and after ibuprofen adsorption. Dissolution testing was conducted on comprimates containing the drug adsorbed on the modified diatomite (composite) and those containing a physical mixture of the drug with the modified diatomite. The antihyperalgesic and the antiedematous activity of ibuprofen from both composites and physical mixtures were evaluated in vivo employing an inflammatory pain model in rats. Functionalization and subsequent drug adsorption had no significant effect on the diatomite ordered porous structure. Two forms of ibuprofen most likely coexisted in the adsorbed state - the acidic form and a salt/complex with aluminium. Both comprimate types showed extended ibuprofen release in vitro, but no significant influence on the duration of the ibuprofen effect was observed upon in vivo application of the composite or physical mixture. However, both the composite and the physical mixture were more effective than equivalent doses of ibuprofen in pain suppression in rats. This potentiation of the ibuprofen antihyperalgesic effect may result from the formation of the drug complex with the carrier and can be of clinical relevance.

A thorough discussion on the Comments on the article "Adsorption of strontium on different sodium-enriched bentonites", by Sanja R. Marinovic, Marija J. Ajdukovic, Natasa P. Jovic-Jovicic, Tihana M. Mudrinic, Bojana N. Nedic-Vasiljevic, Predrag T. Bankovic and Aleksandra D. Milutinovic-Nikolic published in the Journal of the Serbian Chemical Society, Volume 82, Issue 4, Pages: 449-463 (2017), given as Letter to the Editor by S. K. Milonjic, is provided in this letter. The authors of the commented paper have considered all the comments, and responded to each of them, point by point.

Refined diatomite from the Kolubara coal basin (Serbia) was inorganically functionalized through a simple, one-pot, non-time-consuming procedure. Model drug ibuprofen was adsorbed on the functionalized diatomite under optimized conditions providing high drug Loading (similar to 201 mg g(-1)). Physicochemical characterization was performed on the starting and modified diatomite before and after ibuprofen adsorption. Dissolution testing was conducted on comprimates containing the drug adsorbed on the modified diatomite (composite) and those containing a physical mixture of the drug with the modified diatomite. The antihyperalgesic and the antiedematous activity of ibuprofen from both composites and physical mixtures were evaluated in vivo employing an inflammatory pain model in rats. Functionalization and subsequent drug adsorption had no significant effect on the diatomite ordered porous structure. Two forms of ibuprofen most likely coexisted in the adsorbed state - the acidic form and a salt/complex with aluminium. Both comprimate types showed extended ibuprofen release in vitro, but no significant influence on the duration of the ibuprofen effect was observed upon in vivo application of the composite or physical mixture. However, both the composite and the physical mixture were more effective than equivalent doses of ibuprofen in pain suppression in rats. This potentiation of the ibuprofen antihyperalgesic effect may result from the formation of the drug complex with the carrier and can be of clinical relevance.

A thorough discussion on the Comments on the article "Adsorption of strontium on different sodium-enriched bentonites", by Sanja R. Marinovic, Marija J. Ajdukovic, Natasa P. Jovic-Jovicic, Tihana M. Mudrinic, Bojana N. Nedic-Vasiljevic, Predrag T. Bankovic and Aleksandra D. Milutinovic-Nikolic published in the Journal of the Serbian Chemical Society, Volume 82, Issue 4, Pages: 449-463 (2017), given as Letter to the Editor by S. K. Milonjic, is provided in this letter. The authors of the commented paper have considered all the comments, and responded to each of them, point by point.

Heteropoly acid (HPA) was supported on BEA zeolite by optimized synthesis method yielding samples containing different amounts (20 to 50 wt%) of 12-phosphotungstic acid (HPW). The prepared supported HPW samples were subjected to different post-synthesis procedures including calcination and ultrasonication resulting in BEA-HPW (BPW) hybrid materials. These BPW samples were characterized using SEM, N-2-sorption and electrical conductivity measurements. They were subsequently used for the preparation of composites with carbonized polyaniline synthesized in the presence of 5-sulfosalicylic acid, and studied as electrode materials for phenols sensing in acidic, neutral and alkaline media. Linear dependence of current on p-nitrophenol concentration in acidic media was obtained enabling evaluation of limit of detection. Composite electrode gave response to p-nitrophenol presence in alkaline media as well, while no response was recorded in neutral media. The work demonstrates benefits of using novel composite based on BPW hybrid materials and carbonized polyaniline for sensing of phenols in aqueous environmental samples.

Ispitan je mehanizam visoko temperaturskih faznih transformacija cezijum (Cs) izmenjenih zeolita tipa LTA i klinoptilolita (CLI). Analizirane su osobine dobijenih faza u pogledu termalne stabilnosti i otpornosti na luţenje jona cezijuma. Rezultati pokazuju da su dobijene stabilne kristalne alumosilikatne strukture polucita (CsAlSi2O6) i faze CAS (CsAlSi5O12) koje mogu biti matrice za imobilizaciju Cs jona..., The mechanism of high-temperature phase transformation of cesium (Cs) exchanged zeolites such as LTA and clinoptilolite (CLI) was investigated. Thermal stability of obtained phases and their resistance to Cs ion leaching was also analysed. It was shown that the obtained stable, crystalline alumosilicate structures of pollucite (CsAlSi2O6) and CAS phase (CsAlSi5O12) can be used as matrices for Cs ion immobilisation...

Ispitan je mehanizam visoko temperaturskih faznih transformacija cezijum (Cs) izmenjenih zeolita tipa LTA i klinoptilolita (CLI). Analizirane su osobine dobijenih faza u pogledu termalne stabilnosti i otpornosti na luţenje jona cezijuma. Rezultati pokazuju da su dobijene stabilne kristalne alumosilikatne strukture polucita (CsAlSi2O6) i faze CAS (CsAlSi5O12) koje mogu biti matrice za imobilizaciju Cs jona..., The mechanism of high-temperature phase transformation of cesium (Cs) exchanged zeolites such as LTA and clinoptilolite (CLI) was investigated. Thermal stability of obtained phases and their resistance to Cs ion leaching was also analysed. It was shown that the obtained stable, crystalline alumosilicate structures of pollucite (CsAlSi2O6) and CAS phase (CsAlSi5O12) can be used as matrices for Cs ion immobilisation...

Tungstophosphoric acid and BEA zeolite composites were synthesized by wetness impregnation, followed by ultrasonication and calcination. Composites were characterized using Raman spectroscopy, thermal analysis and pH-dependent zeta potential. Spectroscopic measurements indicated the interaction of acid and the support by binding of polyanion terminal oxygens and BEA extra framework H+ via hydrogen bonds. Evaluation of prepared composites revealed their higher efficiency in nicosulfuron adsorption, in comparison to parent zeolite. All prepared composites showed excellent adsorption properties for pesticide removal in the range 12.1-25.8 mg of nicosulfuron per gram of investigated sample. Better adsorption capacity was found for sonicated samples in comparison to as-synthesized and calcined ones. It was found that the amount of polyanion in the composites and the extent of the particles surface charge are not crucial for the adsorption application, it is rather the uniformity of the zeolite surface coverage with the polyanion that is was more important.

An optimized synthetic route for obtaining heteropoly acid (HPA) species supported on BEA zeolite was applied, and different samples, comprising 20 to 50 wt% of 12-phosphotungstic acid (HPW) were prepared. The as-synthesized supported HPW were subjected to different post-synthesis routes, which involved calcination and ultrasound treatment. Characterization of these materials was performed by means of Scanning Electron Microscopy, zeta potential measurements, Infrared Spectroscopy and X-ray Powder Diffraction analysis. Results suggest strong interaction of HPW with the support and revealed that ultrasound treatment resulted in better dispersion of active phase and thus homogeneous morphology of the samples. The zeta potential was found to be dependent on the preparation procedure and HPW content in these materials, while higher HPW loadings induced its agglomeration. Catalytic activity of the synthesized materials was investigated in an ethanol dehydration reaction, where lower HPW loadings induced higher ethanol conversion. Acid sites distribution and accessibility for ethanol molecules were found to be more essential for catalytic activity than HPW loadings, i.e., amount of active sites present in these hybrid materials.

The bio-nanocomposite of montmorillonite and natural biopolymer chitosan (C-MM) was synthesized. Intercalation of chitosan in form of monolayer into the interlamellar space of montmorillonite was confirmed by XRD and IR analysis. The adsorption of textile dyes: Acid Yellow 99 (AY99), Acid Orange 10 (AO10) and Reactive Black 5 (RB5) onto C-MM was investigated. The adsorption was performed with the respect to adsorption time, pH and initial dye concentration. The kinetics of adsorption obeyed pseudo-second-order of kinetics and was the most efficient in acidic pH. Langmuir model best described the adsorption of AY99 and AO10, while RB5 adsorption isotherm was best fitted with Freundlich model.

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0-8.5, the amount of adsorbed Sr2+ was almost constant but 2-3 times smaller than at pH approximate to 11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin-Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

Heterogneous Fenton-like reaction is one of the most efficient solutions for the degradation of organic pollutants in water. A variant of this reaction involves the application of Oxone reagent, based on potassium peroxymonosulfate. Oxone, in conjunction with cobalt, is the source of sulfate radicals. These radicals are very efficient oxidants because of their high standard reduction potential at neutral pH. In this work Co-impregnated Al-pillared clay (CoAP2) was used as heterogeneous catalyst in the degradation of Tartrazine azo-dye in aqueous solutions. For this purpose, Namontmorillonite source clay from Wyoming, USA, with particle diameters of up to 2×10-6 m was submitted to pillaring with aluminium (Keggin ions) and subsequent impregnation with Co(NO3)2 followed by calcination. Morphological and textural characterization as well as phase and chemical characterization were performed on the obtained material. Catalytic degadation of Tartrazine using CoAP2 and Oxone was investigated with respect to reaction temperature in the range from 30–70 °C and monitored using UV-Vis spectroscopy. The obtained spectra indicated that solution decolorization was efficient. Increasing temperature increased decolorization efficiency, and led to the degradation of the dye, the formation and subsequent disappearance of different reaction products. The catalyst showed to be stable under investigated conditions.

The bio-nanocomposite of montmorillonite and natural biopolymer chitosan (C-MM) was synthesized. Intercalation of chitosan in form of monolayer into the interlamellar space of montmorillonite was confirmed by XRD and IR analysis. The adsorption of textile dyes: Acid Yellow 99 (AY99), Acid Orange 10 (AO10) and Reactive Black 5 (RB5) onto C-MM was investigated. The adsorption was performed with the respect to adsorption time, pH and initial dye concentration. The kinetics of adsorption obeyed pseudo-second-order of kinetics and was the most efficient in acidic pH. Langmuir model best described the adsorption of AY99 and AO10, while RB5 adsorption isotherm was best fitted with Freundlich model.

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0-8.5, the amount of adsorbed Sr2+ was almost constant but 2-3 times smaller than at pH approximate to 11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin-Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

Three different bentonites with similar cation exchange capacities were investigatedas adsorbents for Sr2+ionsin aqueous solutions.Textural properties of thebentonite samples were determined using low-temperature N2 physisorption method.Adsorption was carried out with respect to contact time. It was found that adsorption capacity of all adsorbents towards Sr2+ ions was similar.It was shown that ion exchange mechanism is the dominant mechanism of Sr2+ ions adsorption on the Na-enriched bentonites.Adsorption dynamics obeyed pseudo-second-order kinetics model for all bentonites.

Diatomite makes a promising candidate for a drug carrier because of its high porosity, large surface area, modifiable surface chemistry and biocompatibility. Herein, refined diatomite from Kolubara coal basin, which complied with the pharmacopoeial requirements for heavy metals content and microbiological quality, was used as a starting material. Inorganic modification of the starting material was performed through a simple, one-step procedure. Significant increase in adsorbent loading with diclofenac sodium (DS) was achieved after the modification process (~373 mg/g) which enabled the preparation of comprimates containing therapeutic dose of the adsorbed drug. Adsorption of DS onto modified diatomite resulted in the alteration of the drug's XRD pattern and FTIR spectrum. In vitro drug release studies in phosphate buffer pH 7.5 demonstrated prolonged DS release over 8 h from comprimates containing DS adsorbed on modified diatomite (up to 37% after 8 h) and those containing physical mixture of the same composition (up to 45% after 8 h). The results of in vivo toxicity testing on mice pointed on potential safety of both unmodified (starting) and modified diatomite. All these findings favour the application of diatomite as a potential functional drug carrier.

The objective of this study is the structural and morphological characterization of the Ag3PW12O40 salts (AgWPA) of 12-tungstophosphoric acid (WPA) obtained under different preparation conditions and testing of their acid catalytic activity in dehydration of ethanol. The structure, morphology and physicochemical characteristics were determined by Fourier transform infrared (FT-IR) and Raman spectroscopy, X-ray diffraction (XRD), nitrogen physisorption at +/- 196 degrees C, scanning electron microscopy (SEM) and differential thermal (DTA) and thermogravimetric analysis (TGA). It is shown that the preparation process has a significant influence on the morphological properties of the obtained materials which may be explained by the supposed mechanism of the formation of nanocrystallite's aggregates with more or less epitaxial connection. Neutral AgWPA obtained by filtration from supernatant forms porous aggregates of a symmetric dodecahedral shape, having average sizes about 2 mu m. This sample shows higher specific area in comparison with the salt obtained by evaporation due to the higher micropore volume, while mesopore volumes are the same for both salts. Thus conversion of ethanol and selectivities of the main products, ethylene and diethyl ether, are almost the same and constant for both prepared salts, while their values are changed over the reaction time for the parent WPA acid.

The current study reports the synthesis and characterization of tungstophosphoric acid and its acid silver salt supported on mesoporous molecular sieve SBA-15 and TiO2. Because silver salts are partially insoluble, the SBA-15 and TiO2 supported silver acid salts were prepared by two step sequential impregnations. The synthesized catalysts were characterized by various physicochemical methods such as Fourier transform infrared and Raman spectroscopy, differential thermal analysis, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and nitrogen physisorption at -196 degrees C. It is observed that both active phases keep their Keggin-type structure after being supported on the supports while their specific surface area is considerably increased by deposition on mesoporous substrates. The results also indicated that the synthesized catalysts retained the morphology specific for each of the supports, while their thermal stability is increased in comparison with their active phases. The catalytic activity of the prepared catalysts was probed for the vapor phase dehydration of ethanol at 300 degrees C. Results revealed that all the catalysts show considerably improved catalytic activity in comparison to the bulk active phases.

Diatomite makes a promising candidate for a drug carrier because of its high porosity, large surface area, modifiable surface chemistry and biocompatibility. Herein, refined diatomite from Kolubara coal basin, which complied with the pharmacopoeial requirements for heavy metals content and microbiological quality, was used as a starting material. Inorganic modification of the starting material was performed through a simple, one-step procedure. Significant increase in adsorbent loading with diclofenac sodium (DS) was achieved after the modification process (similar to 373 mg/g) which enabled the preparation of comprimates containing therapeutic dose of the adsorbed drug. Adsorption of DS onto modified diatomite resulted in the alteration of the drug's XRD pattern and FTIR spectrum. In vitro drug release studies in phosphate buffer pH 7.5 demonstrated prolonged DS release over 8 h from comprimates containing DS adsorbed on modified diatomite (up to 37% after 8 h) and those containing physical mixture of the same composition (up to 45% after 8 h). The results of in vivo toxicity testing on mice pointed on potential safety of both unmodified (starting) and modified diatomite. All these findings favor the application of diatomite as a potential functional drug carrier.

The objective of this study is the structural and morphological characterization of the Ag3PW12O40 salts (AgWPA) of 12-tungstophosphoric acid (WPA) obtained under different preparation conditions and testing of their acid catalytic activity in dehydration of ethanol. The structure, morphology and physicochemical characteristics were determined by Fourier transform infrared (FT-IR) and Raman spectroscopy, X-ray diffraction (XRD), nitrogen physisorption at +/- 196 degrees C, scanning electron microscopy (SEM) and differential thermal (DTA) and thermogravimetric analysis (TGA). It is shown that the preparation process has a significant influence on the morphological properties of the obtained materials which may be explained by the supposed mechanism of the formation of nanocrystallite's aggregates with more or less epitaxial connection. Neutral AgWPA obtained by filtration from supernatant forms porous aggregates of a symmetric dodecahedral shape, having average sizes about 2 mu m. This sample shows higher specific area in comparison with the salt obtained by evaporation due to the higher micropore volume, while mesopore volumes are the same for both salts. Thus conversion of ethanol and selectivities of the main products, ethylene and diethyl ether, are almost the same and constant for both prepared salts, while their values are changed over the reaction time for the parent WPA acid.

Bentonite from locality Mečji Do was acid treated, characterized and denoted as MDA. The obtained material was used to modify glassy carbon electrode (GCE). The GCE was covered either with a suspension of MDA and Nafion (perfluorinated resin solution), or with the same suspension mixed with Carbon Black Vulcan XC72, Cabot Corporation (CB). Thus the influence of the presence of CB on the electrochemical performance of the modified bentonite based electrodes was examined. The electrochemical properties of the electrodes were tested by cyclic voltammetry in 0.1 M H2SO4 aqueous solution containing 10 mM of phenol, at the scanning rate of 10 mV/s in the potential range from -0.3 V to 1.1 V. The anodic oxidation of phenol led to the formation of insulating polymeric film on modified bentonite based electrode. As a consequence, rapid decrease of the current of phenol oxidation was observed. The composite electrode prepared with CB powder exhibited better performance than its counterpart without CB. Better performance was reflected in the stability of the electrodes regarding electrode fouling during the phenol electrooxidation process and better mechanical durability of the modified bentonite based electrodes.

Diatomite makes a promising candidate for a drug carrier because of its high porosity, large surface area, modifiable surface chemistry and biocompatibility. Herein, refined diatomite from Kolubara coal basin, which complied with the pharmacopoeial requirements for heavy metals content and microbiological quality, was used as a starting material. Inorganic modification of the starting material was performed through a simple, one-step procedure. Significant increase in adsorbent loading with diclofenac sodium (DS) was achieved after the modification process (similar to 373 mg/g) which enabled the preparation of comprimates containing therapeutic dose of the adsorbed drug. Adsorption of DS onto modified diatomite resulted in the alteration of the drug's XRD pattern and FTIR spectrum. In vitro drug release studies in phosphate buffer pH 7.5 demonstrated prolonged DS release over 8 h from comprimates containing DS adsorbed on modified diatomite (up to 37% after 8 h) and those containing physical mixture of the same composition (up to 45% after 8 h). The results of in vivo toxicity testing on mice pointed on potential safety of both unmodified (starting) and modified diatomite. All these findings favor the application of diatomite as a potential functional drug carrier.

The objective of this study is the structural and morphological characterization of the Ag3PW12O40 salts (AgWPA) of 12-tungstophosphoric acid (WPA) obtained under different preparation conditions and testing of their acid catalytic activity in dehydration of ethanol. The structure, morphology and physicochemical characteristics were determined by Fourier transform infrared (FT-IR) and Raman spectroscopy, X-ray diffraction (XRD), nitrogen physisorption at +/- 196 degrees C, scanning electron microscopy (SEM) and differential thermal (DTA) and thermogravimetric analysis (TGA). It is shown that the preparation process has a significant influence on the morphological properties of the obtained materials which may be explained by the supposed mechanism of the formation of nanocrystallite's aggregates with more or less epitaxial connection. Neutral AgWPA obtained by filtration from supernatant forms porous aggregates of a symmetric dodecahedral shape, having average sizes about 2 mu m. This sample shows higher specific area in comparison with the salt obtained by evaporation due to the higher micropore volume, while mesopore volumes are the same for both salts. Thus conversion of ethanol and selectivities of the main products, ethylene and diethyl ether, are almost the same and constant for both prepared salts, while their values are changed over the reaction time for the parent WPA acid.

Nanostructured and granular polyanilines (PANIs) and their composites with zeolite ZSM-5, synthesized by the oxidative polymerization of aniline in water and aqueous solution of sulfuric acid, are evaluated as adsorbents of the organic herbicide glyphosate [N-(phosphonomethyl)glycine] in aqueous solution. The protonated and deprotonated forms of synthesized materials were characterized by elemental and thermogravimetric analysis, scanning electron microscopy, FTIR, Raman and UV-Vis spectroscopies, X-ray powder diffraction, and nitrogen physisorption measurements. The adsorption isotherms of glyphosate on studied materials were best fitted by Freundlich and Langmuir-Freundlich models. The adsorption characteristics of the investigated PANIs and PANI/ZSM-5 composites were found to be much more influenced by the oxidation state and protonation level of PANI in the adsorbents then by the textural and morphological properties of materials. The highest adsorption of glyphosate among all investigated PANI and PANI/ZSM-5 samples, as well as pure ZSM-5, exhibited the deprotonated granular PANI which was synthesized in sulfuric acid medium (98.5 mg/g). High adsorption capacity also showed the deprotonated PANI/ZSM-5 composite with similar to 50% of zeolite (61.9 mg/g) and the protonated nanostructured PANI (59.9 mg/g), both materials prepared in water without added acid.

The silver acid salts AgxH3-xPW12O40 (Ag(x)WPA), where Ag content is x = 1 up to x = 2.5, were synthesized and characterized by Fourier transform infrared and micro-Raman spectroscopy, powder X-ray diffraction and differential thermal and thermogravimetric analysis and nitrogen adsorption. The properties of the prepared salts are compared with those of the parent acid. Regarding the structural, textural and thermal and solubility characteristics, these salts are between salts of group A, with small metal ions, and B group salts with large metal ions. The acid salts are two phase mixtures of soluble acid and insoluble neutral salt, like other alkaline acid salts of H3PW12O40 for x lt 2. The catalytic properties of the acid salts have been studied for the vapor-phase dehydration of ethanol, carried out in a conventional flow-type reactor at 300 degrees C. The acid salts exhibited stable catalytic activity, a little bit lower than tungstophosphoric acid for ethylene production from ethanol.

Nanostructured and granular polyanilines (PANIs) and their composites with zeolite ZSM-5, synthesized by the oxidative polymerization of aniline in water and aqueous solution of sulfuric acid, are evaluated as adsorbents of the organic herbicide glyphosate [N-(phosphonomethyl)glycine] in aqueous solution. The protonated and deprotonated forms of synthesized materials were characterized by elemental and thermogravimetric analysis, scanning electron microscopy, FTIR, Raman and UV-Vis spectroscopies, X-ray powder diffraction, and nitrogen physisorption measurements. The adsorption isotherms of glyphosate on studied materials were best fitted by Freundlich and Langmuir-Freundlich models. The adsorption characteristics of the investigated PANIs and PANI/ZSM-5 composites were found to be much more influenced by the oxidation state and protonation level of PANI in the adsorbents then by the textural and morphological properties of materials. The highest adsorption of glyphosate among all investigated PANI and PANI/ZSM-5 samples, as well as pure ZSM-5, exhibited the deprotonated granular PANI which was synthesized in sulfuric acid medium (98.5 mg/g). High adsorption capacity also showed the deprotonated PANI/ZSM-5 composite with similar to 50% of zeolite (61.9 mg/g) and the protonated nanostructured PANI (59.9 mg/g), both materials prepared in water without added acid.

Nanostructured and granular polyanilines (PANIs) and their composites with zeolite ZSM-5, synthesized by the oxidative polymerization of aniline in water and aqueous solution of sulfuric acid, are evaluated as adsorbents of the organic herbicide glyphosate [N-(phosphonomethyl)glycine] in aqueous solution. The protonated and deprotonated forms of synthesized materials were characterized by elemental and thermogravimetric analysis, scanning electron microscopy, FTIR, Raman and UV-Vis spectroscopies, X-ray powder diffraction, and nitrogen physisorption measurements. The adsorption isotherms of glyphosate on studied materials were best fitted by Freundlich and Langmuir-Freundlich models. The adsorption characteristics of the investigated PANIs and PANI/ZSM-5 composites were found to be much more influenced by the oxidation state and protonation level of PANI in the adsorbents then by the textural and morphological properties of materials. The highest adsorption of glyphosate among all investigated PANI and PANI/ZSM-5 samples, as well as pure ZSM-5, exhibited the deprotonated granular PANI which was synthesized in sulfuric acid medium (98.5 mg/g). High adsorption capacity also showed the deprotonated PANI/ZSM-5 composite with similar to 50% of zeolite (61.9 mg/g) and the protonated nanostructured PANI (59.9 mg/g), both materials prepared in water without added acid.