Merging solution processing and printing for sustainable fabrication of Cu(In,Ga)Se2 photovoltaics

The targeted global decarbonization demands the urgent replacement of conventional fossil fuel with low carbon technologies. For instance, solar energy is abundant, inexhaustible, non-polluting, and low-priced; however, to produce energy on a large scale with reliable, cost-efficient, and environmentally friendly methods remains a challenge. The outstanding optical properties of Cu(In,Ga)Se2 thin film photovoltaics and their intrinsic compatibility with industrial-scale production are paving the way towards this technology. However, most of the activity in the field relies on the use of non-environmentally friendly methodologies to achieve solution-processed flexible and lightweight photovoltaics with significant efficiencies. Importantly, there is a search for more sustainable alternatives that are compatible with roll-to-roll industry to improve the cost-effectiveness and sustainability of photovoltaics without compromising the photovoltaic performance. Herein, we review cost-efficient and sustainable fabrication methodologies that complement the current high- energy-demanding vacuum-based fabrication of Cu(In,Ga)Se2 photovoltaics. The existent non-vacuum deposition methods of Cu(In,Ga)Se2 photoabsorbers are presented and precursors and solvents used in ink formulations are discussed in terms of sustainability. The approaches resulting in most efficient photovoltaic cells are highlighted. Finally, all-solution-processed Cu(In,Ga)Se2 photovoltaics are reviewed, along with the non-vacuum deposition methods of the individual layers, contributing to an even higher throughput and low-cost production. This review highlights the relevance and potential of sustainable non-vacuum methodologies, as well as the need of further investigation in this field to ultimately give access to high-end CIGS PVs with low-cost fabrication.We thank the members of the Nanochemistry Research Group (http://nanochemgroup.org) at INL for insightful discussions and support. This study was conducted with financial support from the Portuguese funding institution FCT – Fundaç ̃ao para Ciˆencia e Tecnologia (PTDC/CTM-ENE/5387/2014, PTDC/NAN-MAT/28745/2017, UID/FIS/04650/2020, UID/QUI/0686/2020, PTDC/FIS-MAC/28157/2017 and SFRH/BD/121780/2016) and Basque Government Industry Department (ELKARTEK and HAZITEK)

A carboxyl-functionalized covalent organic polymer for the efficient adsorption of saxitoxin

Saxitoxin (STX), the most widely distributed neurotoxin in marine waters and emerging cyanotoxin of concern in freshwaters, causes paralytic shellfish poisoning in humans upon consumption of contaminated shellfish. To allow for the efficient monitoring of this biotoxin, it is of high importance to find high-affinity materials for its adsorption. Herein, we report the design and synthesis of a covalent organic polymer for the efficient adsorption of STX. Two β-keto-enamine-based materials were prepared by self-assembly of 2,4,6-triformylphloroglucinol (Tp) with 2,5-diaminobenzoic acid (Pa-COOH) to give TpPa-COOH and with 2,5-diaminotoluene (Pa-CH3) to give TpPa-CH3. The carboxylic acid functionalized TpPa-COOH outperformed the methyl-bearing counterpart TpPa-CH3 by an order of magnitude despite the higher long-range order and surface area of the latter. The adsorption of STX by TpPa-COOH was fast with equilibrium reached within 1 h, and the Langmuir adsorption model gave a calculated maximum adsorption capacity, Qm, of 5.69 mg g-1, making this material the best reported adsorbent for this toxin. More importantly, the prepared TpPa-COOH also showed good reusability and high recovery rates for STX in natural freshwater, thereby highlighting the material as a good candidate for the extraction and pre-concentration of STX from aquatic environments.publishe

Adsorption of marine phycotoxin okadaic acid on a covalent organic framework

Phycotoxins, compounds produced by some marine microalgal species, can reach high concentrations in the sea when a massive proliferation occurs, the so-called harmful algal bloom. These compounds are especially dangerous to human health when concentrated in the digestive glands of seafood. In order to generate an early warning system to alert for approaching toxic outbreaks, it is very important to improve monitoring methods of phycotoxins in aquatic ecosystems. Solid-phase adsorption toxin tracking devices reported thus far based on polymeric resins have not been able to provide an efficient harmful algal bloom prediction system due to their low adsorption capabilities. In this work, a water-stable covalent organic framework (COF) was evaluated as adsorbent for the hydrophobic toxin okadaic acid, one of the most relevant marine toxins and the parental compound of the most common group of toxins responsible for the diarrhetic shellfish poisoning. Adsorption kinetics of okadaic acid onto the COF in seawater showed that equilibrium concentration was reached in only 60 min, with a maximum experimental adsorption of 61 mg g1. Desorption of okadaic acid from the COF was successful with both 70% ethanol and acetonitrile as solvent, and the COF material could be reused with minor losses in adsorption capacity for three cycles. The results demonstrate that COF materials are promising candidates for solid-phase adsorption in water monitoring devices.This article is a result of the project Nanotechnology Based Functional Solutions (NORTE-01-0145-FEDER-000019), supported by Norte Portugal Regional Operational Programme (NORTE2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF). This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 600375.info:eu-repo/semantics/publishedVersio

Covalent organic frameworks as catalyst support: A case study of thermal, hydrothermal, and mechanical pressure stability of β-ketoenamine-linked TpBD-Me2

Covalent organic frameworks (COFs) are crystalline, ordered networks, that, due to their high surface areas and the opportunity for periodic placement of catalytically active sites, are interesting materials for catalysis. Despite the great interest in the use of COFs for this application, there is currently a lack of fundamental understanding on how catalytically relevant conditions affect the integrity of the materials. To gain insight into the stability of COFs as catalyst supports, we herein subjected a β-ketoenamine-linked COF to thermal treatment at high temperatures, to autogenous pressure in water at different temperatures, and to mechanical pressure during pelletizing, after which the materials were thoroughly characterized to gain insight into the structural changes occurring during these catalytically relevant treatments. The COF was largely stable under all hydrothermal conditions studied, highlighting the applicability of β-ketoenamine-linked COFs under aqueous and vapor conditions. On the other hand, thermal and pressure treatments led to a rapid decline in the surface area already at the lowest temperatures and pressures studied. Theoretical calculations indicated this loss to stem from interlayer rearrangement or buckling of the COF layers induced by the applied conditions. This study demonstrates the suitability of β-ketoenamine-linked COFs for use under hydrothermal conditions, and sheds light on the degradation pathways under thermal and pressure treatments, opening the path to the design of COFs with increased stability under such conditions.Fundação para a Ciência e a Tecnologia | Ref. UTA-EXPL/NPN/0055/2019Fundação para a Ciência e a Tecnologia | Ref. PTDC/QUI-OUT/2095/2021Fundação para a Ciência e a Tecnologia | Ref. PTDC/EQU-EQU/1707/2020Agencia Estatal de Investigación | Ref. RYC2020-030414-IUniversidade de Vigo/CISU

Towards all-non-vacuum-processed photovoltaic systems: a water-based screen-printed Cu(In,Ga)Se2 Photoabsorber with a 6.6% efficiency

During the last few decades, major advances have been made in photovoltaic systems based on Cu(In,Ga)Se2 chalcopyrite. However, the most efficient photovoltaic cells are processed under high-energy-demanding vacuum conditions. To lower the costs and facilitate high-throughput production, printing/coating processes are proving to be effective solutions. This work combined printing, coating, and chemical bath deposition processes of photoabsorber, buffer, and transparent conductive layers for the development of solution-processed photovoltaic systems. Using a sustainable approach, all inks were formulated using water and ethanol as solvents. Screen printing of the photoabsorber on fluorine-doped tin-oxide-coated glass followed by selenization, chemical bath deposition of the cadmium sulfide buffer, and final sputtering of the intrinsic zinc oxide and aluminum-doped zinc oxide top conductive layers delivered a 6.6% maximum efficiency solar cell, a record for screen-printed Cu(In,Ga)Se2 solar cells. On the other hand, the all-non-vacuum-processed device with spray-coated intrinsic zinc-oxide- and tin-doped indium oxide top conductive layers delivered a 2.2% efficiency. The given approaches represent relevant steps towards the fabrication of sustainable and efficient Cu(In,Ga)Se2 solar cells.This study was conducted with financial support from the Portuguese Foundation for Science and Technology (PTDC/CTM-ENE/5387/2014, PTDC/NAN-MAT/28745/2017, UID/FIS/04650/2020, UID/QUI/0686/2020, PTDC/FIS-MAC/28157/2017, SFRH/BD/121780/2016 and SFRH/BD/143750/2019) and the Basque Government Industry Department (ELKARTEK and HAZITEK)

Building blocks and COFs formed in concert —Three‐component synthesis of pyrene‐fused Azaacene covalent organic framework in the bulk and as films

A three‐component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation‐inducing COF precursor and the diamines o‐phenylenediamine (Ph), 2,3‐diaminonaphthalene (Naph), or (1R,2R)‐(+)‐1,2‐diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11‐hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene‐fused azaacene, i.e., Aza‐COF series with full conversion of the dione moiety, long‐range order, and high surface area. In addition, the novel three‐component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza‐COFs with nanostructured surfaces on various substrates. The Aza‐COFs exhibit light absorption maxima in the blue spectral region, and each Aza‐COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza‐Ph‐ and Aza‐Naph‐COFs suggest ultrafast relaxation dynamics of excited‐states within these COFs.Deutsche Forschungsgemeinschaft | Ref. ME 4515/1-2Fundação para a Ciência e a Tecnologia | Ref. SFRH/BD/141865/2018Fundação para a Ciência e a Tecnologia | Ref. PTDC/QUI-OUT/2095/2021Fundação para a Ciência e a Tecnologia | Ref. UIDB/50011/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50011/2020Fundação para a Ciência e a Tecnologia | Ref. LA/P/0006/2020National Science Foundation (EE.UU.) | Ref. DMR-1848067Engineering and Physical Sciences Research Council (Reino Unido) | Ref. EP/V055127/1Agencia Estatal de Investigación | Ref. RYC2020-030414-IUniversidade de Vigo/CISU

Gut microbiota develop towards an adult profile in a sex-specific manner during puberty

Accumulating evidence indicates that gut microbiota may regulate sex-hormone levels in the host, with effects on reproductive health. Very little is known about the development of intestinal microbiota during puberty in humans. To assess the connection between pubertal timing and fecal microbiota, and to assess how fecal microbiota develop during puberty in comparison with adult microbiota, we utilized a Finnish allergy-prevention-trial cohort (Flora). Data collected at 13-year follow-up were compared with adult data from a different Finnish cohort. Among the 13-year-old participants we collected questionnaire information, growth data from school-health-system records and fecal samples from 148 participants. Reference adult fecal samples were received from the Health and Early Life Microbiota (HELMi) cohort (n=840). Fecal microbiota were analyzed using 16S rRNA gene amplicon sequencing; the data were correlated with pubertal timing and compared with data on adult microbiota. Probiotic intervention in the allergy-prevention-trial cohort was considered as a confounding factor only. The main outcome was composition of the microbiota in relation to pubertal timing (time to/from peak growth velocity) in both sexes separately, and similarity to adult microbiota. In girls, fecal microbiota became more adult-like with pubertal progression (p= 0.009). No such development was observed in boys (p = 0.9). Both sexes showed a trend towards increasing relative abundance of estrogen-metabolizing Clostridia and decreasing Bacteroidia with pubertal development, but this was statistically significant in girls only (p = 0.03). In girls, pubertal timing was associated positively with exposure to cephalosporins prior to the age of 10. Our data support the hypothesis that gut microbiota, particularly members of Ruminococcaceae, may affect pubertal timing, possibly via regulating host sex-hormone levels.Peer reviewe

Inhaled Sargramostim Induces Resolution of Pulmonary Alveolar Proteinosis in Lysinuric Protein Intolerance

Pulmonary alveolar proteinosis (PAP) is a potentially fatal complication of lysinuric protein intolerance (LPI), an inherited disorder of cationic amino acid transport. The patients often present with mild respiratory symptoms, which may rapidly progress to acute respiratory failure responding poorly to conventional treatment with steroids and bronchoalveolar lavations (BALs). The pathogenesis of PAP in LPI is still largely unclear. In previous studies, we have shown disturbances in the function and activity of alveolar macrophages of these patients, suggesting that increasing the activity and the number of macrophages by recombinant human GM-CSF (rhuGM-CSF) might be beneficial in this patient group.Two LPI patients with complicated PAP were treated with experimental inhaled rhuGM-CSF (sargramostim) after poor response to maximal conventional therapy. BAL fluid and cell samples from one patient were studied with light microscopy and transmission electron microscopy.Excellent response to therapy was observed in patient 1 with no compliance problems or side effects. Macrophages with myelin figure-like structures were seen in her BAL sample. Slight improvement of the pulmonary function was evident also in patient 2, but the role of sargramostim could not be properly evaluated due to the complicated clinical situation.In conclusion, inhaled rhuGM-CSF might be of benefit in patients with LPI-associated PAP.</p

Fecal microbiota in congenital chloride diarrhea and inflammatory bowel disease

Background and aimsSubjects with congenital chloride diarrhea (CLD; a defect in solute carrier family 26 member 3 (SLC26A3)) are prone to inflammatory bowel disease (IBD). We investigated fecal microbiota in CLD and CLD-associated IBD. We also tested whether microbiota is modulated by supplementation with the short-chain fatty acid butyrate.Subjects and methodsWe recruited 30 patients with CLD for an observational 3-week follow-up study. Thereafter, 16 consented to oral butyrate substitution for a 3-week observational period. Fecal samples, collected once a week, were assayed for calprotectin and potential markers of inflammation, and studied by 16S ribosomal ribonucleic acid (rRNA) gene amplicon sequencing and compared to that of 19 healthy controls and 43 controls with Crohn's disease. Data on intestinal symptoms, diet and quality of life were collected.ResultsPatients with CLD had increased abundances of Proteobacteria, Veillonella, and Prevotella, and lower abundances of normally dominant taxa Ruminococcaceae and Lachnospiraceae when compared with healthy controls and Crohn's disease. No major differences in fecal microbiota were found between CLD and CLD-associated IBD (including two with yet untreated IBD). Butyrate was poorly tolerated and showed no major effects on fecal microbiota or biomarkers in CLD.ConclusionsFecal microbiota in CLD is different from that of healthy subjects or Crohn's disease. Unexpectedly, no changes in the microbiota or fecal markers characterized CLD-associated IBD, an entity with high frequency among patients with CLD.Peer reviewe

A post-synthetic modification strategy for the synthesis of pyrene-fused azaacene covalent organic frameworks

Post-synthetic modification strategy is presented to extend the π-system of covalent organic framework (COF) backbone giving access to boronic ester based pyrene-fused azaacene COFs. Optimized catalyst-free reaction conditions yield COFs post-synthetically modified with up to 33% conversion and corresponding intriguing optical properties. The presented chemistry is expected to find application in post-synthetic tailoring of the optical properties of COFs.S.P.S.F. acknowledges the FCT − Fundação para a Ciência e Tecnologia for the Ph.D. scholarship SFRH/BD/131791/2017. This work received funding from the COFforH2 project (UTA-EXPL/NPN/0055/2019) through the Portuguese Foundation for Science and Technology funds under UT Austin Portugal, Charm project (PTDC/QUI-OUT/2095/2021) through the Portuguese Foundation for Science and Technology funds, The Excellence Clusters ‘Nanosystems Initiative Munich (NIM)’, and from the Free State of Bavaria through the Research Network ‘Solar Technologies go Hybrid’.Peer reviewe