Dopant-additive synergism enhances perovskite solar modules.

Perovskite solar cells (PSCs) are among the most promising photovoltaic technologies owing to their exceptional optoelectronic properties1,2. However, the lower efficiency, poor stability and reproducibility issues of large-area PSCs compared with laboratory-scale PSCs are notable drawbacks that hinder their commercialization3. Here we report a synergistic dopant-additive combination strategy using methylammonium chloride (MACl) as the dopant and a Lewis-basic ionic-liquid additive, 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl). This strategy effectively inhibits the degradation of the perovskite precursor solution (PPS), suppresses the aggregation of MACl and results in phase-homogeneous and stable perovskite films with high crystallinity and fewer defects. This approach enabled the fabrication of perovskite solar modules (PSMs) that achieved a certified efficiency of 23.30% and ultimately stabilized at 22.97% over a 27.22-cm2 aperture area, marking the highest certified PSM performance. Furthermore, the PSMs showed long-term operational stability, maintaining 94.66% of the initial efficiency after 1,000 h under continuous one-sun illumination at room temperature. The interaction between [Bcmim]Cl and MACl was extensively studied to unravel the mechanism leading to an enhancement of device properties. Our approach holds substantial promise for bridging the benchtop-to-rooftop gap and advancing the production and commercialization of large-area perovskite photovoltaics.

MOF-Based Solid-State Proton Conductors Obtained by Intertwining Protic Ionic Liquid Polymers with MIL-101.

Solid-state proton conductors based on the use of metal-organic framework (MOF) materials as proton exchange membranes are being investigated as alternatives to the current state of the art. This study reports a new family of proton conductors based on MIL-101 and protic ionic liquid polymers (PILPs) containing different anions. By first installing protic ionic liquid (PIL) monomers inside the hierarchical pores of a highly stable MOF, MIL-101, then carrying out polymerization in situ, a series of PILP@MIL-101 composites was synthesized. The resulting PILP@MIL-101 composites not only maintain the nanoporous cavities and water stability of MIL-101, but the intertwined PILPs provide a number of opportunities for much-improved proton transport compared to MIL-101. The PILP@MIL-101 composite with HSO4 - anions shows superprotonic conductivity (6.3 × 10-2  S cm-1 ) at 85 °C and 98% relative humidity. The mechanism of proton conduction is proposed. In addition, the structures of the PIL monomers were determined by single crystal X-ray analysis, which reveals many strong hydrogen bonding interactions with O/NH···O distances below 2.6 Å.

The Chemistry of the Passivation Mechanism of Perovskite Films with Ionic Liquids.

Passivation of perovskite films by ionic liquids (ILs) improves the performance (efficiency and stability) of perovskite solar cells (PSCs). However, the role of ILs in the passivation of perovskite films is not fully understood. Here, we report the reactions of commonly used ILs with the components of perovskites. The reaction of ILs with perovskite precursors (PbI2 and methylammonium iodide or formamidinium iodide) in a 1:1:1 molar ratio affords one-dimensional (1D) salts composed of the IL cation interspersed along infinite 1D polymeric [PbI3]-n chains. If the IL is applied in excess, the resulting crystal is composed of six cations surrounding a discrete [Pb3I12]6- cluster. All the isolated salts were unambiguously characterized by single-crystal X-ray diffraction analysis, which also reveals extensive hydrogen-bonding interactions.

Creative Construction of a Series of Chiral 3D Indium-Organic Frameworks with a umy Topology.

Using 2,2'-R2-biphenyl-4,4'-dicarboxylic acid to bind with a cis-[InO4(µ2-OH)2] octahedron, three novel chiral 3D indium-organic frameworks, [In(µ2-OH)L] [1, L1, R = N(CH3)2; 2, L2, R = OCH3; 3, L3, R = CH3], have been hydrothermally synthesized without chiral reagents. Crystal structure analyses reveal that 1-3 show an unprecedented 4-connected umy topology with the Schläfli symbol (42·64). 1 exhibits high water stability and good sorption selectivity of CO2 over N2, while 3 displays high C2H2, C2H4, and C2H6 uptake capacity at 273 K.

Retarding solid-state reactions enable efficient and stable all-inorganic perovskite solar cells and modules.

All-inorganic CsPbI3 perovskite solar cells (PSCs) with efficiencies exceeding 20% are ideal candidates for application in large-scale tandem solar cells. However, there are still two major obstacles hindering their scale-up: (i) the inhomogeneous solid-state synthesis process and (ii) the inferior stability of the photoactive CsPbI3 black phase. Here, we have used a thermally stable ionic liquid, bis(triphenylphosphine)iminium bis(trifluoromethylsulfonyl)imide ([PPN][TFSI]), to retard the high-temperature solid-state reaction between Cs4PbI6 and DMAPbI3 [dimethylammonium (DMA)], which enables the preparation of high-quality and large-area CsPbI3 films in the air. Because of the strong Pb-O contacts, [PPN][TFSI] increases the formation energy of superficial vacancies and prevents the undesired phase degradation of CsPbI3. The resulting PSCs attained a power conversion efficiency (PCE) of 20.64% (certified 19.69%) with long-term operational stability over 1000 hours. A record efficiency of 16.89% for an all-inorganic perovskite solar module was achieved, with an active area of 28.17 cm2.

Rational Design of a Gd(III)-Cu(II) Nanobooster for Chemodynamic Therapy Against Cancer Cells.

Copper (II) containing coordination complexes have attracted much attention for chemodynamic therapy (CDT) against cancer cells. In this study, the bimetallic nanobooster [Gd2Cu(L)2(H2O)10]·6H2O was prepared by a solvothermal method based on tetrazole carboxylic acid ligand H4L [H4L = 3,3-di (1H-tetrazol-5-yl) pentanedioic acid]. It showed considerable cytotoxicity toward three kinds of human cancer cells (HeLa, HepG2, and HT29). The MTT assay showed that the IC50 (half-maximal inhibitory concentration) of the complex NPs on HeLa cells (4.9 µg/ml) is superior to that of HepG2 (11.1 µg/ml) and HT29 (5.5 µg/ml). This result showed that [Gd2Cu(L)2(H2O)10]·6H2O NPs can inhibit cell proliferation in vitro and may be potential candidates for chemodynamic therapy. In addition, the cytotoxicity was also confirmed by the trypan blue staining experiment. The results promise the great potential of Gd(III)-Cu(II) for CDT against cancer cells.

Corrigendum: Rational design of a Gd(III)-Cu(II) nanobooster for chemodynamic therapy against cancer cells.

[This corrects the article DOI: 10.3389/fchem.2022.856495.].

Ba-MOFs with tetrazole-based acetic acids: unusual configuration, novel topology and high proton conductivity.

Metal-organic frameworks (MOFs) as proton-conductive materials have attracted increasing attention due to their applications in proton-exchange membrane fuel cells. While the majority of the MOFs are based on transition metals, group II metals with unusual configurations have received relatively less attention. In this work, we selected three tetrazole-based acetic acids, N,N-di(2-carboxymethyltetrazol-5-yl)amine (H2L1), 1,3,5-tri(2-carboxymethyltetrazol-5-yl)benzene (H3L2), and 4,5-di(tetrazol-5-yl)imidazolylacetic acid (H3L3), as ligands and prepared three MOFs with barium(ii) ions: [Ba2(L1)2(H2O)5]·2H2O (1), (Me2NH2)[Ba(L2)(H2O)]·3H2O (2), and [Ba3(µ2-H2O)(L3)2(H2O)3]·2H2O (3). Ba-MOFs have been unambiguously characterized by elemental, FT-IR spectroscopy and single-crystal X-ray diffraction analyses. In the solid state, 2D MOF 1 with two nine-coordinated Ba(ii) centers shows a rare hula hoop-like geometry at the Ba1 atom and a distorted tricapped trigonal prismatic geometry around the Ba2 one. Unusual sphenocorona geometry is also found in MOF 2 with a ten-coordinated Ba(ii) ion. In MOF 3, three different Ba(ii) ions coexist with two nine-coordinated Ba1 and Ba2 displaying a muffin-like configuration and a distorted tricapped trigonal prism geometry, respectively, and an eight-coordinated Ba3 having a distorted biaugmented trigonal prism geometry. In addition, MOF 2 exhibits an unprecedented trinodal 3,7,7-connected 3D network with the Schläfli symbol (37·46·52·62·74)(37·46·52·63·73)2(63) and MOF 3 displays a novel trinodal 4,5,9-connected 3D framework with the Schläfli symbol (421·615)(45·6)(48·62). Due to the presence of extensive hydrogen bonded networks consisting of dimethyl ammonium and water molecules in the 1D channels, MOF 2 shows a high proton conductivity of 4.47 × 10-3 S cm-1 at 85 °C and 98% relative humidity (RH).

Two topologically different 3D CuII metal-organic frameworks assembled from the same ligands: control of reaction conditions.

Bifunctional ligands containing both carboxylic and sulfonate groups can adopt versatile coordination modes to produce novel metal-organic frameworks (MOFs) with high-dimensional networks and interesting topologies. Using 2,2'-disulfonylbiphenyl-4,4'-dicarboxylic acid (H4L) as a linker and 4,4'-bipyridine (4,4'-bpy) as a co-ligand, two novel 3D CuII MOFs, {[Cu2(L)(4,4'-bpy)2.5(H2O)]·1.7H2O}n, (1), and {[Cu2(L)(4,4'-bpy)2]·DMA·3H2O}n, (2), have been synthesized and structurally characterized by X-ray crystallography (DMA is N,N-dimethylacetamide). MOF (1) shows an unprecedented trinodal 4,4,5-connected topology network with the Schläfli symbol (4.62.73)(43.65.7.8)(6.73.8.10), while MOF (2) indicates a binodal 4,6-connected fsc network with the Schläfli symbol (44.610.8)(44.62). MOFs (1) and (2) were further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. MOF (1) shows a high water and chemical stability. The proton conductivity of (1) and CO2 adsorption of (2) were also investigated.

Three novel topologically different metal-organic frameworks built from 3-nitro-4-(pyridin-4-yl)benzoic acid.

The design and synthesis of metal-organic frameworks (MOFs) have attracted much interest due to the intriguing diversity of their architectures and topologies. However, building MOFs with different topological structures from the same ligand is still a challenge. Using 3-nitro-4-(pyridin-4-yl)benzoic acid (HL) as a new ligand, three novel MOFs, namely poly[[(N,N-dimethylformamide-κO)bis[µ2-3-nitro-4-(pyridin-4-yl)benzoato-κ3O,O':N]cadmium(II)] N,N-dimethylformamide monosolvate methanol monosolvate], {[Cd(C12H7N2O4)2(C3H7NO)]·C3H7NO·CH3OH}n, (1), poly[[(µ2-acetato-κ2O:O')[µ3-3-nitro-4-(pyridin-4-yl)benzoato-κ3O:O':N]bis[µ3-3-nitro-4-(pyridin-4-yl)benzoato-κ4O,O':O':N]dicadmium(II)] N,N-dimethylacetamide disolvate monohydrate], {[Cd2(C12H7N2O4)3(CH3CO2)]·2C4H9NO·H2O}n, (2), and catena-poly[[[diaquanickel(II)]-bis[µ2-3-nitro-4-(pyridin-4-yl)benzoato-κ2O:N]] N,N-dimethylacetamide disolvate], {[Ni(C12H7N2O4)2(H2O)2]·2C4H9NO}n, (3), have been prepared. Single-crystal structure analysis shows that the CdII atom in MOF (1) has a distorted pentagonal bipyramidal [CdN2O5] coordination geometry. The [CdN2O5] units as 4-connected nodes are interconnected by L- ligands to form a fourfold interpenetrating three-dimensional (3D) framework with a dia topology. In MOF (2), there are two crystallographically different CdII ions showing a distorted pentagonal bipyramidal [CdNO6] and a distorted octahedral [CdN2O4] coordination geometry, respectively. Two CdII ions are connected by three carboxylate groups to form a binuclear [Cd2(COO)3] cluster. Each binuclear cluster as a 6-connected node is further linked by acetate groups and L- ligands to produce a non-interpenetrating 3D framework with a pcu topology. MOF (3) contains two crystallographically distinct NiII ions on special positions. Each NiII ion adopts an elongated octahedral [NiN2O4] geometry. Each NiII ion as a 4-connected node is linked by L- ligands to generate a two-dimensional network with an sql topology, which is further stabilized by two types of intermolecular OW-HW...O hydrogen bonds to form a 3D supramolecular framework. MOFs (1)-(3) were also characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetic analysis. Furthermore, the solid-state photoluminescence of HL and MOFs (1) and (2) have been investigated. The photoluminescence of MOFs (1) and (2) are enhanced and red-shifted with respect to free HL. The gas adsorption investigation of MOF (2) indicates a good separation selectivity (71) of CO2/N2 at 273 K (i.e. the amount of CO2 adsorption is 71 times higher than N2 at the same pressure).

The synergistic effects of TaAGP.L-B1 and TaSSIVb-D mutations in wheat lead to alterations of gene expression patterns and starch content in grain development.

Starch is synthesized from a series of reactions catalyzed by enzymes. ADP-glucose pyrophosphorylase (AGPase) initiates the synthesis pathway and synthesizes ADP-glucose, the substrate of starch synthase (SS), of which SSIV is an isoform. Mutations of the AGPase subunit and SSIV-coding genes affect starch content and cause variation in the number of granules. Here, we pyramided the functional mutation alleles of the AGPase subunit gene TaAGP.L-B1 and the SSIV-coding gene TaSSIVb-D to elucidate their synergistic effects on other key starch biosynthesis genes and their impact on starch content. Both the TaAGP.L-B1 and TaSSIVb-D genes were expressed in wheat grain development, and the expression level of TaAGP.L-B1 was higher than that of TaSSIVb-D. The TaAGP.L-B1 gene was downregulated in the agp.L-B1 single and agp.L-B1/ssIV-D double mutants at 12 to 18 days after flowering (DAF). TaSSIVb-D expression was significantly reduced at 6 DAF in both ssIV-D single and double mutants. In the agp.L-B1/ssIV-D double mutant, TaGBSSII was upregulated, while TaAGPSS, TaSSI, and TaSBEII were downregulated. Under the interaction of these genes, the total starch and amylopectin contents were significantly decreased in agp.L-B1 and agp.L-B1/ssIV-D mutants. The results suggested that the mutations of TaAGP.L-B1 and TaSSIVb-D genes resulted in variation in the expression patterns of the other four starch synthetic genes and led to a reduction in starch and amylopectin contents. These mutants could be used further as germplasm for resistant starch analysis.

EcoTILLING Reveals Natural Allelic Variations in Starch Synthesis Key Gene TaSSIV and Its Haplotypes Associated with Higher Thousand Grain Weight.

Wheat is a staple food commodity grown worldwide, and wheat starch is a valuable source of energy and carbon that constitutes 80% of the grain weight. Manipulation of genes involved in starch synthesis significantly affects wheat grain weight and yield. TaSSIV plays an important role in starch synthesis and its main function is granule formation. To mine and stack more favorable alleles, single nucleotide polymorphisms (SNPs) of TaSSIV-A, B, and D were investigated across 362 wheat accessions by Ecotype-Targeting Induced Local Lesions IN Genome (EcoTILLING). As a result, a total of 38 SNPs in the amplified regions of three TaSSIV genes were identified, of which 10, 15, and 13 were in TaSSIV-A, B, and D, respectively. These 38 SNPs were evaluated by using KASP and six SNPs showed an allele frequency >5% whereas the rest were <5%, i.e., considered to be minor alleles. In the Chinese mini core collection, three haplotypes were detected for TaSSIV-A and three for TaSSIV-B. The results of an association study in the Chinese mini core collection with thousand grain weight (TGW) and spike length (SPL) showed that Hap-2-1A was significantly associated with TGW and Hap-3-1B with SPL. Allelic frequency and geographic distribution indicated that the favored haplotype (Hap-2-1A) has been positively selected in Chinese wheat breeding. These results suggested that the Kompetitive Allele Specific PCR (KASP) markers can be applied in starch improvement to ultimately improve wheat yield by marker assisted selection in wheat breeding.