Publications

Abstract The authors regret the existence of an error on one of the results reported in the original and published manuscript. The error has been identified and rectified as follows: • In Abstract, page 2469: the half-life period of “23.8 ± 0.6 s” should be read as “47.6 ± 1.1 s”. • In page 2472, section Results and discussion, second paragraph: the half life was “23.8 ± 0.6 s” should be read as “47.6 ± 1.1 s”. • In page 2478, section Conclusions, first paragraph: the half life period of “23.8 ± 0.6 s” should be read as “47.6 ± 1.1 s”. The authors would like to apologise for any inconvenience caused to the editorial staff and the editor of the Journal of Environmental Chemical Engineering, as well as all its valuable readers and followers.

Abstract Pharmaceuticals are invaluable tools for the prevention and treatment of human and animal diseases. Human evolution led to the increase of life expectancy, which promoted the increase of consumption of pharmaceuticals. These compounds are consistently detected in superficial waters, and whilst degradation processes are expected to mitigate their levels, they also induce the formation of potentially harmful by-products. The compounds studied in this work were acetaminophen, 17 alpha-ethynylestradiol and carbamazepine. High-performance liquid chromatography coupled with ultraviolet diode-array detection was used to follow the degradation reactions, whilst liquid chromatography associated with ultraviolet diode-array detection and mass spectrometry was applied in the determination of by-products. Ethynylestradiol proved to be the most reactive (t(1/2) = 38.6 +/- 1.9 seconds) and carbamazepine the least reactive (t(1/2) = 481.4 +/- 16.7 minutes) when exposed to active chlorine. In relation to disinfection by-products, two monochlorinated analogues were detected for acetaminophen, one monochlorinated for carbamazepine, and one mono- and one trichlorinated for ethynylestradiol. Chlorine levels and water pH proved to be the most influential variables on the degradation of the compounds, with and without dissolved organic matter in solution. All pharmaceuticals displayed significant photostability towards artificial solar radiation, with acetaminophen being slightly more stable.

Abstract This work reports the role of different dispersants, namely, polyethylene glycol (PEG 200 2%), ethylene glycol 5%, ethanol 2%, dimethyl sulfoxide (DMSO 5%), and polyvinyl alcohol (PVA 5%) in the toxicity profile of several commercial nanomaterials (NM), such as hydrophilic and hydrophobic TiO2, hydrophilic SiO2, SiO2 in aqueous suspension (aq), and ZnO towards the bioluminescent bacterium Aliivibrio fischeri. The majority of NM showed tendency to form agglomerates in the different dispersants. Although some particle agglomeration could be detected, DMSO at 5% was the best dispersant for hydrophobic TiO2 NM while PVA at 5% was the most effective dispersant for the other types of NM. Average size was not the most relevant aspect accounting for their toxicity. A remarkable reduction in average size was followed by a decrease in NM toxicity, as demonstrated for SiO2 aq. in PVA 5%. Contrarily, despite of high particle agglomeration, ZnO NM showed a higher toxicity to bacteria when compared with other tested NM. Independently of the average particle size or surface charge, the dispersant either enhanced the toxicity to bacteria or acted as physical barrier decreasing the NM harmful effect to A. fischeri.

Abstract The efficiency and associated environmental impacts of different N-doping strategies of carbon dots (CDs) were evaluated. More specifically, N-doped CDs were prepared from citric acid via two main synthesis routes: Microwave-assisted hydrothermal treatment with addition of N-containing small organic molecules (urea and ethylenediamine (EDA)); and microwave-assisted solvothermal treatment in N-containing organic solvents (n,n-dimethylformamide (DMF), acetonitrile and pyridine). These syntheses produced CDs with similar blue emission. However, XPS analysis revealed that CDs synthesized via both hydrothermal routes presented a better N-doping efficiency (15 at.%) than all three solvothermal-based strategies (0.6-7 at.%). However, from the former two hydrothermal strategies, only the one involving EDA as a nitrogen-source provided a non-negligible synthesis yield, which indicates that this should be the preferred strategy. This conclusion was supported by a subsequent life cycle assessment (LCA) study, which revealed that this strategy is clearly the most sustainable one from all five studied synthesis routes.

Abstract The study of sensing materials to the detection of carbon dioxide (CO2) was achieved using p-nitrophenol (pNPh) as a colorimetric indicator. The sensing material was polymerized (NPLn), functionalized with 3-triethoxysilyl propyl isocyanate (IPTES) which sensitivity was tested in the form of a membrane as is and encapsulated in hollow silica nanoparticles. The sensing membranes were tested in a closed gas system comprising very precise flow controllers to deliver different concentrations of CO2 (vs. N2). The combination of the sensing membranes with multimode optical fibers and a dual-wavelength diode (LED) allows the measurement of the CO2 through the analysis of the induced absorbance changes with a self-referenced ratiometric scheme. The analysis of the sensing materials have shown significant changes in their chemical and physical properties and the results attest these materials with a strong potential for assessing CO2 dynamics in environmental, medical, and industrial applications.

Abstract Metal and alloys electrodeposition from aqueous electrolytes is restricted due to the narrow electrochemical window and hydrogen evolution. To overcome these disadvantages, over the past years, ionic liquids (ILs) and deep eutectic solvents (DES) based on choline chloride have been successfully applied for the electrodeposition of different metals. Tin (Sn) layers applied to automotive or decorative plating are thought of as ecological alternatives to exchange lead and nickel/chromium coatings. Over the past few years, the attention drawn by metallic alloys and composites, namely Sn alloys (nickel, indium, copper, zinc…) and Sn-carbon materials composites, has increased due to the possibility of applying these materials as anodes for lithiumion batteries. This review will highlight the leading research regarding the electrodeposition of Sn and several alloys and carbon composites, emphasizing the morphological changes of the alloy combinations using DESs as electrolytes.

Abstract The impact of fullerene side chain functionalization with thiophene and carbazole groups on the device properties of bulk-heterojunction polymer:fullerene solar cells is discussed through a systematic investigation of material blends consisting of the conjugated polymer poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3'"-di(2-octyldodecyl)-2,2 ' ;5 ' ,2 '' ;5 '' ,2'"-quaterthiophen-5,5'"-diyl)] (PffBT4T-2OD) as donor and C-60 or C-70 fulleropyrrolidines as acceptors. The photovoltaic performance clearly depended on the molecular structure of the fulleropyrrolidine substituents although no direct correlation with the surface morphology of the photoactive layer, as determined by atomic force microscopy, could be established. Although some fulleropyrrolidines possess favorable lowest unoccupied molecular orbital levels, when compared to the standard PC71BM, they originated OPV cells with inferior efficiencies than PC71BM-based reference cells. Fulleropyrrolidines based on C-60 produced, in general, better devices than those based on C-70, and we attribute this observation to the detrimental effect of the structural and energetic disorder that is present in the regioisomer mixtures of C-70-based fullerenes, but absent in the C-60-based fullerenes. These results provide new additional knowledge on the effect of the fullerene functionalization on the efficiency of organic solar cells.

Abstract The synthesis of noble metal nanoparticles (i.e., silver and gold) for electrochemical applications has been widely studied using mainly wet synthesis chemical methods or electrochemical deposition methods. In this work, we propose a single-step flash photochemical method for synthesizing noble metal nanoparticles (i.e., silver, gold, and Au:Ag) in solution for electrochemical applications. The method is based on the intense pulsed radiation emitted from a xenon flashlamp, which induce the reduction of metal cations in solution to form metallic nanoparticles. The present method is based on the selective light absorption of the metal precursor salts combined with the decomposition of polyvinylpyrrolidone added to the solution. This approach can be termed as flash light synthesis.

Abstract Ion transfer electrochemistry is a powerful tool for the study of ionic species in solution. In this paper, square wave voltammetry and chronoamperometry are applied for the quantification and characterization of denatonium ion (N-benzyl-2-(2,6-dimethylphenylamino)-N,N-diethyl-2-oxoethanarninium) in water, an important additive present in commercial products. The method presented is based on the monitoring of the transfer of the cation across a microporous membrane separating an aqueous solution and an organic solution of 1,2-dichloroethane. Calibration curves are built with both techniques and the resulting detection limits and linear ranges of response are discussed. Furthermore, the different performance characteristics of the two techniques are exploited to extract the values of the aqueous diffusion coefficient of the ion denatonium and its standard transfer potential from water to 1,2-dichloroethane. The last parameter is of great importance for the evaluation of the ion lipophilicity, that plays a role in its distribution in living organisms and its impact on biological media. (C) 2020 Elsevier B.V. All sights reserved.

Abstract New molecular dynamics (MD) simulations and experimental data on a deep eutectic solvent, propeline, composed by choline chloride, ChCl, and propylene glycol, PG, in a molar ratio of 1:2 are reported in this work. The experimental physicochemical properties (density, viscosity and self-diffusion coefficients) were used as support in the development of a new OPLS based force field model (FFM) for propeline. Validation of the new force field was established both through measuring physicochemical properties over a range of temperatures (298.15-373.15 K) and by comparison with experimental and simulated data of ethaline (ChCl:ethylene glycol, at a molar ration of 1:2). Classical MD simulations using the new FFM led to good agreement between experimental and simulated data. Structural properties, namely radial and spatial distribution functions, coordination numbers, and hydrogen bonding were analyzed. Moreover, it was found that the interactions between the anion, Cl-, and the hydrogen bond donor (HBD) form a network that is immutable with increasing temperature. The higher prevalence of anion-HBD hydrogen bonds is likely the major reason for the relatively high viscosity of propeline.