Ca-based materials derived from calcined cigarette butts for CO_(2)capture and thermochemical energy storage

Cigarette butts(CBs)are one of the most common types of litter in the world.Due to the toxic substances they contain,the waste generated poses a harmful risk to the environment,and therefore there is an urgent need for alternative solutions to landfill storage.Thus,this work presents a possible revalorization of this waste material,which implies interesting environmental benefits.CBs were used as sacrificial templates for the preparation of CaO-based materials by impregnation with calcium and magnesium nitrates followed by flaming combustion.These materials presented enhanced porosity for their use in the Calcium Looping process applied either to thermochemical energy storage or CO_(2)capture applications.The influence of the concentration of Ca and Mg in the impregnating solutions on the multicycle reactivity of the samples was studied.An improved multicycle performance was obtained in terms of conversion for both applications.

Neuroprotective effects of metalosalen complexes against oxidative stress

Neurodegenerative diseases and oxidative stress:During the metabolic processes,O2 can accept unpaired electrons to form superoxide radical species(O2^·–),which are able to generate hydrogen peroxide(H2O2)with a fast dismutation,therefore increasing the hydroxyl radical(HO^·)levels.These species and other radicals(·OOH,ROO^·,RO^·,CO3^·–),which can be produced through a sequence of reactions,constitute the designated reactive species of oxygen(ROS).Oxidative stress is caused by a disequilibrium between the ROS produced and the antioxidant defence against them(catalase enzymes,superoxide dismutase(SOD)and glutathione peroxidases,in addition to other non-enzymatic antioxidants,such asα-tocopherol,ascorbic acid and carotenes).

Vapor Phase Decarbonylation of Furfural to Furan over Nickel Supported on SBA-15 Silica Catalysts

Vapor-phase transformations of furfural over SBA-15 silica supported Ni catalysts under H2 in a continuous-flow reactor at atmospheric pressure and 170°C and 230°C were investigated. Two different samples having Ni loadings of 5 and 20 wt% (denoted here by SBA-5Ni and SBA-20Ni, respectively) were prepared by impregnation and characterized by atomic absorption spectroscopy, N2 sorption analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Furan and furfuryl alcohol were two primary products resulting, respectively, from decarbonylation and hydrogenation of furfural. Under the conditions of the study, both reactions exhibited structure sensitivity evidenced by changes in product selectivities with variable Ni loadings. Compared with SBA-20Ni, the 5 wt% Ni catalyst showed better catalytic activity, reaching a furfural conversion of 100 mol% and a selectivity to furan of 98 mol%, after 5 h of time-on-stream at 230°C.

Fabrication Parameter Optimization for a Multilayer Photovoltaic Cell Based on the Heterojunction: Zinc(II)-Meso-Tetrakis(4-Bromophenyl) Porphyrins/Fullerenes

The photoelectric properties of multilayer organic photovoltaic cells (OPV cells) were studied. The active organic layers consisted of a planar heterojunction between a layer of Meso-Tetrakis(4-BromoPhenyl) Zinc(II) Porphyrin (BrPhPZn) as electron donor (ED) and a layer fullerene molecules. The devices were fabricated in a high vacuum by thermal sublimation, a technique that allows multilayer devices realization easily by successive depositions, and it does not require solvents, achieving purer films with reproducible characteristics. Taking into account that the anodic contact, a key factor for cell efficiency, is favored by the inclusion of a thin anodic buffer layer (ABL), the effect on the yield after including one or two (ABL): MoO3 or MoO3-CuI layers was studied. The cell which has the best photovoltaic characteristics has a BrPhPZn (ED) thickness of only 12.5 nm. This small thickness is related with the low conductivity of this organic molecule. On the other hand, including a thin MoO3-CuI bilayer increased, such device’s efficiency in a 200%, with regard to a cell without ABL, getting for one cell ITO/MoO3-CuI/BrPhPZn/C60/Alq3/Al, with a 1.03% yield.

Experimental and Computational Study of the Effect of Temperature on the Electro-Polymerization Process of Thiophene

Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.

Robust hybrid bismuth perovskites as potential photocatalysts for overall water splitting

Organic-inorganic hybrid perovskites have gained great attention as promising photocatalysts for hydrogen generation.However,due to their poor stability in water,the use of aqueous hydrohalic acid solutions is specifically required for an efficient hydrogen evolution.Herein,three novel photoactive lead-free hybrid perovskites based on bismuth and triazolium cations(denoted as IEF-15,IEF-16,and IEF-17(IEF stands for IMDEA energy frameworks))were synthesized and fully characterized(structural,compositional,optical,etc.).Further,these solids were proposed as photocatalysts for the challenging gas phase overall water splitting(OWS)reaction.Accordingly,IEF-16 thin films exhibited a remarkable photocatalytic activity in both H_(2) and O_(2) evolution,as a consequence of its appropriate bandgap and energy-band alignment,achieving hydrogen evolution rates ofμmol·g_(H_(2))^(-)1846 and 360 after 24 h under ultraviolet-visible(UV-vis)irradiation or simulated solar irradiation,respectively.This study additionally highlights the remarkable structural and photochemical stability of IEF-16 under different operational conditions(i.e.water volume,irradiation and temperature),paving the way for green hydrogen production from OWS using perovskite-based photocatalysts.

Attaching CF_(3) groups to organic molecules using trifluoroacetates via ion-shielding photoelectrocatalysis

Fluorinated molecules play a protagonist role in pharmaceuticals, agrochemicals, and materials. The incorporation of fluoroalkyl groups into organic compounds provides them with unique chemical properties that are key to the design and development of bioactive compounds with improved pharmacokinetics [1].

Biomass gasification,catalytic technologies and energy integration for production of circular methanol:New horizons for industry decarbonisation

The Intergovernmental Panel on Climate Change(IPCC)recognises the pivotal role of renewable energies in the future energy system and the achievement of the zero-emission target.The implementation of renewables should provide major opportunities and enable a more secure and decentralised energy supply system.Renewable fuels provide long-term solutions for the transport sector,particularly for applications where fuels with high energy density are required.In addition,it helps reducing the carbon footprint of these sectors in the long-term.Information on biomass characteristics feedstock is essential for scaling-up gasification from the laboratory to industrial-scale.This review deals with the transformation biogenic residues into a valuable bioenergy carrier like biomethanol as the liquid sunshine based on the combination of modified mature technologies such as gasification with other innovative solutions such as membranes and microchannel reactors.Tar abatement is a critical process in product gas upgrading since tars compromise downstream processes and equipment,for this,membrane technology for upgrading syngas quality is discussed in this paper.Microchannel reactor technology with the design of state-of-the-art multifunctional catalysts provides a path to develop decentralised biomethanol synthesis from biogenic residues.Finally,the development of a process chain for the production of(i)methanol as an intermediate energy carrier,(ii)electricity and(iii)heat for decentralised applications based on biomass feedstock flexible gasification,gas upgrading and methanol synthesis is analysed.

A new series of environment-friendly reddish inorganic pigments based on AFeO_(3)(A=Ln,Y) with high NIR solar reflectance

Environment-friendly pigments based on AFeO_(3)(A=La,Pr,Nd,Sm,Gd,Tb,Y or Yb)with high nearinfrared(NIR)reflectance were synthesised by a coprecipitation method at 1200℃.The Rietveld refinement analysis showed single-phase orthorhombic perovskite for all compositions.All pigments,which showed reddish hues,offered good colour stability after mixing these pigments in powder form with siloxane transparent paint and two different glazes.The powderepaint mixtures produced with GdFeO_(3),TbFeO_(3) and YFeO_(3) pigments have the highest NIR solar reflectance,reaching values of R=50%.The temperature shielding studies conducted using TbFeO_(3) pigmentepaint mixture for a roof coating yielded a reduction of 3.2℃ in comparison to a commercial pigment.Moreover,the glazes that were pigmented using GdFeO_(3),TbFeO_(3) and YFeO_(3) compositions also presented the most intense reddish colours.A study of the thermal and chemical stability of the pigment with the highest NIR solar reflectance showed good stability in both cases.The reddish pigments that were prepared can therefore be good candidates for use in different applications such as cool pigments or pigments for ceramic glazes at high temperatures.