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Volatile A-cation halide (AX) additives such as formamidinium chloride and methylammonium chloride have been widely employed for high-efficiency perovskite solar cells (PSCs). However, it remains unstudied how they influence the perovskite film stoichiometry and the solar cell performance and operational stability. Hereby, our work shows that over annealing of formamidinium chloride-containing perovskite films leads to a Pb-rich surface, resulting in a high initial efficiency, which however decays during maximum power point tracking (MPPT). On the contrary, perovskite films obtained by a shorter annealing time at the same temperature provide good stability during MPPT but a lower initial efficiency. Thus, we deduce that an optimal annealing is vital for both high efficiency and operational stability, which is then confirmed in the case where methylammonium chloride additive is used. With optimized perovskite annealing conditions, we demonstrate efficient and stable p-i-n PSCs that show a best power conversion efficiency of 20.7% and remain 90% of the initial performance after a 200 h MPPT at 60 °C under simulated 1 sun illumination with high UV content. Our work presents a comprehensive understanding on how volatile AX impacts perovskite film stoichiometry and its correlation to the device performance and operational stability, providing a new guideline for fabricating high-efficiency and operationally stable PSCs.

Co-free Li-rich layered oxides are gaining interest as feasible positiveelectrode materials in lithium-ion batteries (LIBs) in terms of energy density, costreduction, and alleviating safety concerns. Unfortunately, their commercialization ishindered by severe structural degradation that occurs during electrochemical operation.The study at hand demonstrates advanced structural engineering of a Li-rich Co-freeoxide with composition Li1.1Ni0.35Mn0.55O2by spray pyrolysis and subsequentcalcination of an aqueous precursor, creating a segregated structure of two distinctlayered phases with space groupsR3??m(rhombohedral) andC2/m(monoclinic). Thisparticular structure was investigated with powder neutron diffraction, high-resolutionanalytical transmission electron microscopy imaging, and electron energy loss spectroscopic characterization. This complex structurecontributes to the high electrochemical stability and good rate capability observed for this compound (160 mAh/g at C/3 and 100mAh/g at 1C).These results provide new insights into the feasibility of developing and commercializing cobalt-free positiveelectrode materials for LIBs The authors acknowledge funding from Generalitat de Catalunya 2017 SGR 1246 and 2017 SGR 327 and the Spanish MINECO project ENE2017-85087-C3 and PID2020- 116093RB-C43 / AEI / 10.13039/501100011033. IREC is funded by the CERCA Programme/Generalitat de Catalunya. IREC also acknowledges additional support from the European Regional Development Funds (ERDF, FEDER). This research was funded by HORIZON 2020-supported EU project COBRA, grant number H2020-EU.3.4.-875568. The authors also acknowledge Stephen Hull and Ron Smith for collecting neutron data at the ISIS neutron and the muon source using rapid access. The experiment number was 2000189.

Biobased and biodegradable polyhydroxyalkanoates (PHAs) are currently gaining momentum. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) polymer has a useful processing window for extrusion and injection molding of packaging, agricultural and fishery applications with required flexibility. Processing PHBHHx into fibers using electrospinning or centrifugal fiber spinning (CFS) can further broaden the application area, although CFS remains rather unexplored. In this study, PHBHHx fibers are centrifugally spun from 4-12 wt.% polymer/chloroform solutions. Beads and beads-on-a-string (BOAS) fibrous structures with an average diameter (ϕav) between 0.5 and 1.6 µm form at 4-8 wt.% polymer concentrations, while more continuous fibers (ϕav = 3.6-4.6 µm) with few beads form at 10-12 wt.% polymer concentrations. This change is correlated with increased solution viscosity and enhanced mechanical properties of the fiber mats (strength, stiffness and elongation values range between 1.2-9.4 MPa, 11-93 MPa, and 102-188%, respectively), though the crystallinity degree of the fibers remains constant (33.0-34.3%). In addition, PHBHHx fibers are shown to anneal at 160 °C in a hot press into 10-20 µm compact top-layers on PHBHHx film substrates. We conclude that CFS is a promising novel processing technique for the production of PHBHHx fibers with tunable morphology and properties. Subsequent thermal post-processing as a barrier or active substrate top-layer offers new application potential. This research was funded by the Special Research Fund (BOF) of Hasselt University, grant number BOF20DOC06. The authors acknowledge Prof, Wouter Marchal (Analytical&Circular Chemistry, IMO-IMOMEC,UHasselt) for providing access to the DSC and rheometer equipment and Prof Louis Pitet (Advanced Polymer Functionalization, IMO-IMOMEC, UHasselt) for access to the hot-press. Jorgo Merchiers is acknowledged for the initial work on centrifugal fiber spinning, equipment development, polymer solution preparation, fiber fabrication and characterization. Lieze Schruers is acknowledged for the preliminary work on testing polymer concentrations for PHBHHx fibers using CFS.

The minimization of nonradiative recombination losses is essential to transcend the efficiency of state-of-the-art organic solar cells (OSCs) and near- infrared (NIR) organic light- emitting diodes (OLEDs). Indeed, reduced nonradiative processes will result in high electroluminescence (EL), external quantum efficiency (EQE(EL)), and low nonradiative voltage losses (Delta V-OC,V- nr) for OSCs. Here, we study the EL properties of a set of polymer-small molecule blends and find a relationship between the EL emission linewidth, EQEEL, and Delta V-OC,V-nr. Based on these findings, we reduce Delta V-OC,V-nr from the typical values around 250 mV down to an unprecedented value of 155 mV using a blend comprising a low- molecular-weight PM6 polymer donor and a highly emissive nonfullerene acceptor (Y16F). Importantly, the PM6:Y16F blend yields an EQE(EL) ( 0.52%) among the best reported fluorescent NIR-OLEDs in the 900-nm range. These findings clearly indicate the existence of organic material blends that combine both excellent photovoltaic and electroluminescent properties. European Union's Horizon 2020 research and innovation program under the Marie-Curie grant [88279]; FWOFWO [G0D0118N, G0B2718N, G0D1521N, I006320N, GOH3816-NAUHL]; European Research Council (ERC)European Commission [864625]; FWO Odysseus program [G0D0115N]

Nanometer-thick, ultrathin coatings applied over a large area are of paramount importance for various application fields such as biomedicine, space and automotive, organic electronics, memory devices, or energy storage devices. So far wet chemical deposition as a cost-effective, scalable, and versatile method can only be used for thicker deposits. Here the formation of uniform ultra-thin coatings with thicknesses below 15nm using a nature-inspired, roll-to-roll compatible Spray-on-Screen (SoS) technology is reported. For this, the finite micro-droplet generation of Ultrasonic Spray Coating (USSC) is combined with the coating formation from a screen printing mesh. Hydrophobic micro-threads of the mesh, resembling the micro-hair on the legs of water striders, produce millidroplets from microdroplets, and when applying external pressure to the mesh, dynamic wetting is enforced. The proposed technology is applicable for a wide variety of substrates and applications. It is shown by theory and experiment that ultra-thin coatings below 5nm homogeneous over a large area can be deposited without the use of extended ink formulation or high substrate temperatures during or after deposition. This simple yet effective technique enables the deposition of ultra-thin films on any substrates, and is very promising to fabricate the organic, inorganic electronics devices and batteries cost effectively.

At present, two-dimensional (2D) hybrid organic-inorganic perovskites (HOIPs) are drawing significant interest because of their potential use in different optoelectronic applications, that is, photovoltaics and photodetectors. Here, we report on a series of 2D layered HOIPs (Bit-C3)(2)PbX4 (with X = Cl, Br, and I) containing a 2,2'-bithiophene chromophore functionalized with a propylammonium tethering chain as a model molecule. The optical properties, crystal structure, and phase behavior of the 2D layered HOIPs are studied in depth. The crystal structures with the chemical formula (Bit-C3)(2)PbX4 (with X = Cl, and Br) are successfully obtained. Contrastingly, different crystal structures with an inorganic framework containing face- and corner-sharing octahedra were identified for the iodide-based HOIP. The phase diversity and thermal stability of the (Bit-C3)(2)PbX4 (with X = Cl, Br, and I) thin films were investigated via in situ measurements. Here, the presence of lower-dimensional hybrids with reduced electronic dimensionality within the iodide-based thin film is demonstrated. Additionally, we show that the 2D hybrid thermal stability is dependent on the type of lead(II)halide framework employed. We suggest that, via halide substitution from iodide to bromide and chloride, the molecular degrees of freedom of the Bit-C3 ammonium cations are reduced by spatial confinement of a smaller inorganic framework, therefore, limiting the formation of lower-dimensional hybrids besides the targeted 2D layered HOIP. This study illustrates the importance of efficiently utilizing the space supplied by the inorganic framework in which the organic ammonium cations can reside within a 2D layered HOIP. This, in turn, dictates how the organic ammonium cations arrange themselves within the organic layer and influences the adopted crystal structure of the hybrid.

Low-dimensional (2D or 1D) hybrid perovskites are receiving increased attention due to their structural flexibility and enhanced stability compared to their 3D counterparts. Understanding the phase formation and degradation behavior of these materials is crucial towards their use in optoelectronic devices, since different crystal phases possess different optical and electronic properties. In this communication, we study the phase formation and degradation of a series of hybrids containing bithiophene, terthiophene and quaterthiophene derivatives. We show that two crystal phases can be formed for each of these systems, depending on the processing conditions. One phase corresponds to a 2D layered perovskite and the other phase has optical properties corresponding to a dimensionality intermediate between a 2D and a 1D hybrid.

Volatile A-cation halide (AX) additives such as formamidinium chloride and methylammonium chloride have been widely employed for high-efficiency perovskite solar cells (PSCs). However, it remains unstudied how they influence the perovskite film stoichiometry and the solar cell performance and operational stability. Hereby, our work shows that over annealing of formamidinium chloride-containing perovskite films leads to a Pb-rich surface, resulting in a high initial efficiency, which however decays during maximum power point tracking (MPPT). On the contrary, perovskite films obtained by a shorter annealing time at the same temperature provide good stability during MPPT but a lower initial efficiency. Thus, we deduce that an optimal annealing is vital for both high efficiency and operational stability, which is then confirmed in the case where methylammonium chloride additive is used. With optimized perovskite annealing conditions, we demonstrate efficient and stable p–i–n PSCs that show a best power conversion efficiency of 20.7% and remain 90% of the initial performance after a 200 h MPPT at 60 °C under simulated 1 sun illumination with high UV content. Our work presents a comprehensive understanding on how volatile AX impacts perovskite film stoichiometry and its correlation to the device performance and operational stability, providing a new guideline for fabricating high-efficiency and operationally stable PSCs.

We introduce an efficient framework for investigating the heterogeneity in battery porous electrodes and its impacts on the performance and longevity of lithium-ion batteries. A phenomenological pi...

In this study, we sought to compose consortia of plant growth-promoting (PGP) and trace element tolerant bacteria, to improve plant growth and inhibit uptake and translocation of trace elements, ev...

A comprehensive study was undertaken to obtain a more fundamental understanding of the phase behavior of the p-DTS(FBTTh2)2:PC71BM system, used in small molecule organic solar cells, with a strong focus on the amorphous phase and its influence on crystallinity. Three dedicated thermal protocols were used in combination with advanced thermal analysis, solid-state NMR, and wide-angle X-ray diffraction. Rapid cooling, to avoid structure formation and gain insight in the amorphous phase, and slow cooling, to promote structure formation, were used as limiting cases to explain the intermediate behavior after device processing from solution. A complete state diagram was developed, and the glass transition (Tg)–composition relationship was determined. In the case of slow cooling and the procedure used for device processing, the rapid crystallization of p-DTS(FBTTh2)2 leads to an enrichment of the amorphous phase in PC71BM, increasing its Tg and causing vitrification of the mixed amorphous phase before crystallizationwhen the total amount of PC71BM exceeds 70 wt %. The common processing additive 1,8-diiodooctane (DIO) was found to lead to a lower p-DTS(FBTTh2)2 crystallinity and smaller average crystal size. More importantly, it acts as a strong plasticizer, lowering Tg significantly and thus reducing the morphological stability of the p-DTS(FBTTh2)2:PC71BM mixtures.

Because of their intriguing properties for optoelectronic applications, research on organicsemiconducting polymershas steadily progressed over the past decades, yielding increasingly fine-tuned (hetero)aromaticpolymer backbones. In this work, the push-pullcopolymerPDTPQx is synthesized, bothviaStillepolycondensationand direct arylation polymerization (DArP), permitting comparison of the two procedures. Near-infrared organicphotodetectors(OPDs) are constructed based on these different polymer batches in combination with PC61BM, and their performance was investigated. From the current-voltage characteristics, it is clear that the DArP polymer-based devices outperform those prepared from the Stille polymers, both in terms of dark current density andexternal quantum efficiency(EQE), and therefore in terms of specific detectivity as well. The relatively high highest occupied molecular orbital energy level of PDTPQx, in combination with the clear charge-transfer absorption band observed for the DArP-based device, is beneficial for application in organicresonant cavityphotodetectors. Such OPDs are prepared for the DArP PDTPQx:PC61BM (1:4) blends with 180 and 210nm thick bulkheterojunctionactive layers. EQEs of 2.5% at 1016nm and 1% at 1140nm are achieved, with full-width-at-half-maximum peak responses of 44 and 45nm, respectively, and detectivities of 2.24×1010and 1.06×1010Jones.

Because of their intriguing properties for optoelectronic applications, research on organic semiconducting polymers has steadily progressed over the past decades, yielding increasingly fine-tuned (hetero)aromatic polymer backbones. In this work, the push-pull copolymer PDTPQx is synthesized, both via Stille poly-condensation and direct arylation polymerization (DArP), permitting comparison of the two procedures. Near-infrared organic photodetectors (OPDs) are constructed based on these different polymer batches in combination with PC 61 BM, and their performance was investigated. From the current-voltage characteristics, it is clear that the DArP polymer-based devices outperform those prepared from the Stille polymers, both in terms of dark current density and external quantum efficiency (EQE), and therefore in terms of specific detectivity as well. The relatively high highest occupied molecular orbital energy level of PDTPQx, in combination with the clear charge-transfer absorption band observed for the DArP-based device, is beneficial for application in organic resonant cavity photodetectors. Such OPDs are prepared for the DArP PDTPQx:PC 61 BM (1:4) blends with 180 and 210 nm thick bulk heterojunction active layers. EQEs of 2.5% at 1016 nm and 1% at 1140 nm are achieved, with full-width-at-half-maximum peak responses of 44 and 45 nm, respectively, and detectivities of 2.24 × 10 10 and 1.06 × 10 10 Jones. The authors thank Huguette Penxten for CV analysis, Christel Willems for the TEM sample preparation, and Brent Fripont for the graphical abstract artwork. We also thank the Research Foundation – Flanders (FWO Vlaanderen) for continuing financial support (projects G0D0118 N, G0B2718 N, 1S50820 N, 11D2618 N), as well as the European Research Council (ERC, grant agreement 864625). Dr. Q. Liu acknowledges financial support from the European Union’s Horizon 2020 research and innovation program under the Marie-Curie grant agreement no. 88279.

Driven by expanding interest in battery storage solutions and the success story of lithium-ion batteries, the research for the discovery and optimization of new battery materials and concepts is at peak. The generation of experimental (dis)charge data using coin cells is fast and feasible and proves to be a favorite practice in the battery research labs. The quantitative interpretation of the data, however, is not trivial and decelerates the process of screening and optimization of electrode materials and recipes. Here, we introduce the concept of polarographic map and demonstrate how it can be leveraged to quantify the contribution of different non-equilibrium phenomena to the performance limitation and total polarization of a lithium-ion cell. We showcase the accuracy and diagnostic power of this approach by preparing and analyzing the electrochemical performance of 54 sets of LiNixMnyCo1-x-yO2 electrodes with different formulations and designs discharged in a range of 0.2C to 5C.

Seed endophyte inoculation can enhance the plant tolerance to pollutants, which allows plant cultivation on trace element (TE) polluted soils. Methylobacterium sp. CP3 and Kineococcus en-dophyticus CP19 were tested in vitro for their tolerance to Zn and Cd and their plant growth promotion traits. The in vivo effects of bioaugmentation with individual strains or both strains were tested using two poplar cultivars, Populus deltoides x (P. trichocarpa x P. maximowiczii) ‘Dender’ and ‘Marke’, grown in TE polluted soil for six weeks. Methylobacterium sp. was found to grow on media enriched with 0.4 and 0.8 mM Cd, and both endophytes tolerated 0.6 and 1 mM Zn, due to the presence of genes involved in Zn and Cd tolerance and transport. Methylobacterium sp. showed an extracellular ion sequestration mechanism. Production of indole-3-acetic acid by Methylobacterium sp. and K. en-dophyticus, as well as phosphorus solubilization by Methylobacterium sp. were observed. Bioaugmen-tation with both endophytes increased the shoot length of Populus ‘Marke’ and enhanced the Mg uptake in both cultivars. Inoculation with Methylobacterium sp. reduced the bioaccumulation of Zn in ‘Marke’, conferring it an excluder strategy. Methylobacterium sp. and K. endophyticus seemed to improve the plant nutritional status, which can alleviate abiotic stress. Fil: Vannucchi, Francesca. Scuola Superiore Sant’Anna; Italia Fil: Imperato, Valeria. Hasselt University; Bélgica Fil: Saran, Anabel. Hasselt University; Bélgica. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina Fil: Staykov, Svetoslav. Hasselt University; Bélgica Fil: D'Haen, Jan. Hasselt University; Bélgica Fil: Sebastiani, Luca. Scuola Superiore Sant’Anna; Italia Fil: Vangronsveld, Jaco. Hasselt University; Bélgica. Maria Curie-Skłodowska University; Polonia Fil: Thijs, Sofie. Hasselt University; Bélgica

Lighting today is expected to be light weighted, flexible, highly efficient, non-expensive and fabricated in an environment friendly way. Organic light emitting diodes (OLEDs) meet all of these requirements and can be applied using inexpensive and roll-to-roll compatible printing techniques. This work demonstrates the ultrasonic spray coating (USSC) of polyethylenimine (PEI) and polyethylenimine(ethoxylated) (PEIE) as electron injection/transport layer (EIL/ETL) for OLEDs. This high-end printing technique employs ultrasonic atomization to break down a liquid into a spray of homogeneous small (20 µm) droplets. The PEI(E) layer was optimised using USSC and subjected to a complete morphological and electro-optical characterisation. For all manufactured devices current and voltage characteristics and luminous performances were obtained. This study confirms the versatility of USSC and the suitability of PEI(E) as excellent EIL/ETL for OLEDs and paves the way towards fully printed devices.

In this contribution, a cost- and time- effective contacting approach is presented for dielectric-based rear surface passivation layers up to 30 nm. Nano-size and homogenously distributed openings are realized in AlOx passivation layer by selenization of LiF salt on top, and monitored via SEM. Further, this layer was implemented into sub-micron thick CIGS solar cells. Consequently, contact openings facilitate the current collection through the dielectric layer up to 30 nm thick. However, solar cell parameters remain the same, even worse than the reference. Thus, this approach is still open for optimizations.

Hybrid titania phosphonate materials can demonstrate a high added value as tailored sorption materials. They combine high chemical stability with great structural versatility, given the wide diversity of functional groups that can be incorporated. Hereto, a fundamental understanding of the synthesis strategies influencing the material performance is required. Therefore three porous TiO2 phosphonate hybrid structures with different functional groups (octyl, propyl, and phenyl) were evaluated in a solid-phase extraction application aimed towards solvent separation. The synthesis was performed by mixing bridged diphosphonic acids (DPAs) with Ti(OBu)4 in a water-ethanol mixture at 30 °C, followed by a hydrothermal post-treatment at 120 °C. The materials were characterized by ICP-AES, 31P solid-state CP/MAS NMR, Raman and FTIR spectroscopy, X-ray diffraction, N2-sorption, and transmission electron microscopy. It is shown that the diphosphonic acids are quantitatively incorporated in the hybrid structures, leading to nanosized particles with a complex but uniquely functionalized surface. A study of the pore structure as a function of the incorporated DPA amount showed materials with a maximum BET surface area of 379 m2/g. The alkyl functionalized hybrid titania phosphonates demonstrated excellent and tunable sorption behavior.

Ni-rich layered lithium transition metal oxides (LiNi x Mn y Co z O 2) have gained significant attention as high-capacity positive electrode materials for lithium-ion batteries. However, their poor cyclability, capacity retention, and rate capability at higher working potentials limit their applications in commercial batteries. Here, we demonstrate a cost-effective chemical solution deposition route of a thin TiO x shell on LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC-622) particles and the effect of surface modification on the electrochemical properties. The crystallinity and morphology of the NMC-622 particles are unaffected by the deposition step and verified by powder X-ray diffraction and electron microscopy. High-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) analysis showed that the TiO x surface layer is amorphous and prone to enhance the electronic conductivity of the cathode material. The TiO x-coated material has an improved rate performance and experiences a lower charge-transfer resistance compared to the pristine material. The effect of the surface modification on the electrochemical performance of NMC-622 was investigated further by the assembly of NMC-622/Li 4 Ti 5 O 12 (LTO) full cells. The beneficial impact of the TiO x coating on the electrochemical performance of NMC-622 positive electrodes in lithium-ion battery applications was showcased by the higher initial Coulombic efficiency and lower aging rates during 150 cycles at 1C in NMC-622/LTO cells.

Modern lighting is expected to be light weight, flexible, efficient, non-expensive and environmentally friendly fabricated. Organic light emitting diodes (OLEDs) meet all these requirements and can be manufactured using inexpensive and roll-to-roll compatible printing techniques. They, however, often use low work function, highly reactive metals, such as barium and calcium to facilitate electron injection, deposited using expensive and non-continuous vacuum techniques. Efficient and stable alternatives can be found in the aliphatic amines, polyethylenimine (PEI) and polyethylenimine(ethoxylated) (PEIE), that shift the work function of aluminum favorably for electron injection. This work demonstrates ultrasonic spray coating of PEI(E) as electron injection and transport layer for OLEDs, reducing the work function of the aluminum cathode by 0.355 eV allowing a luminous efficacy comparable to that of the OLEDs using calcium/aluminum electrodes. Slightly higher luminous results are noted for the OLEDs with spin coated PEI(E), indicating that the surface morphology and thickness of the PEI(E) layer are crucial factors: ultrasonic spray coated PEI(E) layers have an increased overall thickness and surface roughness. This study shows the potential of ultrasonic spray coating and the suitability of PEI(E) as excellent electron injection and transport layer for OLEDs and paves the way towards fully spray coated OLEDs. K E Y W O R D S electron injection and transport layer, organic light emitting diodes, printing techniques, ultrasonic spray coating This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

npj Materials degradation 5(1), 29 (2021). doi:10.1038/s41529-021-00169-2, Detrimental corrosion is an ever-concerning challenge for metals and alloys. One possible remedy is to apply organic corrosion inhibitors. Despite progress in molecular assembly and inhibitor research, better mechanistic insight on the molecular level is needed. Here we report on the behavior of well-defined artificial molecular interfaces created by micro-contact printing of thiol-inhibitor molecules and subsequent backfilling. The obtained heterogeneity and defects trigger localized dealloying-corrosion of well-defined Cu3Au surfaces. The stability of applied inhibitor molecules depends on alloy surface morphology and on intermolecular forces of the molecular layers. On extended terraces, dealloying preferentially starts at the boundary between areas composed of the two different chain-length inhibitor molecules. Inside of the areas hardly any nucleation of initial pits is visible. Step density strongly influences the morphology of the dealloying attack, while film heterogeneity avoids cracking and controls molecular-scale corrosion attack. The presented surface-science approach, moreover, will ultimately allow to verify the acting mechanisms of inhibitor-cocktails to develop recipes to stabilize metallic alloy surfaces., Published by Macmillan Publishers Limited, part of Springer Nature, [London]

The gradual loss of capacity and increase in the cell impedance are the mainstream of aging patterns for the lithium-ion batteries and mainly result from the depletion of cell’s cyclable-lithium reservoir. The irreversible drain from this reservoir is well understood and originates from the phenomena such as electrolyte oxidation and reduction at the electrode/electrolyte interfaces. There is, however, limited knowledge about the circumstances leading to the recuperation of misplaced lithium, gain in cell’s energy, and impedance drop. Here, we showcase that the intragranular fracture induces a peculiar aging behavior in the LiNi0.6Mn0.2Co0.2O2 electrodes. Fracture enables an alternative path for the (de)insertion of lithium from the hard-to-reach center of the secondary particles by lithium pore-wall flux instead of solid-state diffusion. The possible consequences are the energy recovery and decrease of the charge-transfer resistance in the electronically well wired electrodes.

The removal of Ibuprofen was investigated by activated carbon impregnated with TiO2. Emphasis was given on the effect of different parameters, such as composite type, initial Ibuprofen concentration (5–25 mg/L), temperature (22–28 °C) and pH (acidic and alkaline solution). The experiment was carried out in a self-made tubular flow reactor, with one 15 W monochromatic UV lamp (254 nm). The composite AC90T10 gives the highest removal degree of 92% of Ibuprofen solution under UV light within 4 h, due to synergy of adsorption and photodegradation. It was found that weight ratio of composite/Ibuprofen has limited effect on the removal degree within the concentration range (5–25 mg/L), but reaction time under UV light (4 h) and pH (acidic solution) are very important. The kinetic experimental data obtained at pH 4.3 at 25 °C on different composites were fitted to pseudo-first, pseudo-second and Elovich models, obtaining a high accuracy based on R2 values. From the results, composites of granular activated carbon and TiO2 can enhance removal of Ibuprofen effectively, making recycle process much easier and less costly, which can be a promising method in future water treatment.

Low-dimensional hybrid perovskites are receiving increased attention. One of the advantages of the low-dimensional hybrids over their 3D counterparts is their greater structural flexibility towards the incorporation of bigger, more complex, organic cations. In this communication, we introduce a pyrene derivative as an organic cation containing an extended pi-system for use in a variety of low-dimensional hybrids. We show that materials with different excitonic absorption features can be obtained by tuning the iodide/lead ratio in the precursor solutions, using the same pyrene cation. In this way, hybrids with optical characteristics corresponding to 2D, 1D and 0D hybrid perovskites are obtained. The formation and thermal stability of the different hybrids is analysed and compared.

Molecularly imprinted polymers (MIPs) can selectively bind target molecules and can therefore be advantageously used as a low-cost and robust alternative to replace fragile and expensive natural receptors. Yet, one major challenge in using MIPs for sensor development is the lack of simple and cost-effective techniques that allow firm fixation as well as controllable and consistent receptor material distribution on the sensor substrate. In this work, a convenient method is presented wherein microfluidic systems in conjunction with in situ photo-polymerization on functionalized diamond substrates are used. This novel strategy is simple, efficient, low-cost and less time consuming. Moreover, the approach ensures a tunable and consistent MIP material amount and distribution between different sensor substrates and thus a controllable active sensing surface. The obtained patterned MIP structures are successfully tested as a selective sensor platform to detect physiological concentrations of the hormone disruptor testosterone in buffer, urine and saliva using electrochemical impedance spectroscopy. The highest added testosterone concentration (500 nM) in buffer resulted in an impedance signal of 10.03 ± 0.19% and the lowest concentration (0.5 nM) led to a measurable signal of 1.8 ± 0.15% for the MIPs. With a detection limit of 0.5 nM, the MIP signals exhibited good linearity between a 0.5 nM and 20 nM concentration range. Apart from the excellent and selective recognition offered by these MIP structures, they are also stable during and after the dynamic sensor measurements. Additionally, the MIPs can be easily regenerated by a simple washing procedure and are successfully tested for their reusability.

Aslihan Babayigit obtained her bachelor's degree in Biomedical Sciences at Hasselt University in 2013. After having completed her degree with a Masters in Bioelectronics and Nanotechnology in 2015, she is currently pursuing a Doctorate in Sciences as a PhD fellow of Research Fund Flanders (FWO) in the Nanostructure Physics Group at the Institute for Materials Research (IMO-IMOMEC) of Hasselt University. Her current research involves various physical and chemical aspects of the film formation of photovoltaic perovskites, where additional focus is directed toward their environmental screening and eco-friendly processing. Jan D'Haen is full professor at Hasselt University. After obtaining his PhD in 1996 on plasma nitriding of pure iron, he became responsible for several physical and chemical analytical characterization techniques at the Materials Research Institute (IMO) of Hasselt University. His specialties are diffraction (XRD, EBSD) and scanning and transmission electron microscopy, investigating a wide range of material classes, including hybrid metal halide perovskites. Hans-Gerd Boyen studied mathematics and physics at the University of Karlsruhe where he also obtained a PhD in Physics. Subsequently, he worked as post-doc at the University of Basel (habilitation in physics) and as senior scientist at the University of Ulm focusing on topics in nanoscience and nanotechnology. In 2007, he became full professor of Experimental Physics at the Institute for Materials Research (IMO-IMOMEC) at Hasselt University, heading the Nanostructure Physics Group ever since. Research topics include nanomaterials, molecular layers, cubic boron nitride, perovskite-based thin film photovoltaics, surfaces and interfaces in general, all studied by exploiting a variety of electron spectroscopic tools. Bert Conings obtained his master's degree in Applied Physics (Nanoscience and Technology) at the Eindhoven University of Technology (NL) in 2008. He completed his PhD on hybrid solar cells at Hasselt University (BE) in 2012. He was then appointed as postdoctoral researcher at Hasselt University, where he became a postdoctoral fellow of the Research Foundation Flanders (FWO) in 2013. His core focus is perovskite photovoltaics at the device level and the material level. More generally, his interests include the electro-optical characterization of nanostructured materials for applications in energy and life sciences.