Fabrication of mixed perovskite organic cation thin films via controllable cation exchange

Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails a facile drop-casting of formamidinium iodide（FAI） solutions on as-prepared MAPbI_3 perovskite thin films under the controlled conditions,which leads to controllable displacement of the MA~＋ cations by FA~＋ cations in the perovskite structure at room temperature. Uniform and controllable mixed organic cation perovskite thin films without a ＂bi-layered＂ or graded structure are achieved. By applying this approach to photovoltaic devices, we are able to improve the performances of devices through extending their optical-absorption onset further into the infrared region to enhance solar-light harvesting. Additionally,this work provides a simple and efficient technique to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials for high-performance perovskite solar cells.

Bile duct ligation differently regulates protein expressions of organic cation transporters in intestine,liver and kidney of rats through activation of farnesoid X receptor by cholate and bilirubin

Body is equipped with organic cation transporters(OCTs).These OCTs mediate drug transport and are also involved in some disease process.We aimed to investigate whether liver failure alters intestinal,hepatic and renal Oct expressions using bile duct ligation(BDL)rats.Pharmacokinetic analysis demonstrates that BDL decreases plasma metformin exposure,associated with decreased intestinal absorption and increased urinary excretion.Western blot shows that BDL significantly downregulates intestinal Oct2 and hepatic Oct1 but upregulates renal and hepatic Oct2.In vitro cell experiments show that chenodeoxycholic acid(CDCA),bilirubin and farnesoid X receptor(FXR)agonist GW4064 increase OCT2/Oct2 but decrease OCT1/Oct1,which are remarkably attenuated by glycine-β-muricholic acid and silencing FXR.Significantly lowered intestinal CDCA and increased plasma bilirubin levels contribute to different Octs regulation by BDL,which are confirmed using CDCA-treated and bilirubin-treated rats.A disease-based physiologically based pharmacokinetic model characterizing intestinal,hepatic and renal Octs was successfully developed to predict metformin pharmacokinetics in rats.In conclusion,BDL remarkably downregulates expressions of intestinal Oct2 and hepatic Oct1 protein while upregulates expressions of renal and hepatic Oct2 protein in rats,finally,decreasing plasma exposure and impairing hypoglycemic effects of metformin.BDL differently regulates Oct expressions via Fxr activation by CDCA and bilirubin.

Morphology mediation of MoS_(2) nanosheets with organic cations for fast sodium ion storage

Ion diffusion kinetics,depending on the size,tortuosity,connectivity of the channels,greatly affects the rate performance of the electrodes.Two-dimensional materials(2DMs) has emerged as promising electrode materials in the past decades.Howeve r,the applications of 2DMs electrodes are limited by the strong restacking problem,which leads to a poor rate capability.In this work,we for the first time mediated the mo rphology of molybdenum disulfide(MoS_(2)) nanosheets via a facile coagulation method;abundant sheet crumples were induced,which greatly enhance their surface accessibility and thus benefit the ion diffusion kinetics.Consequently,the crumpled-MoS_(2) electrodes follow a capacitive Na-ion charge-storage mechanism to a large extent.Importantly,we demonstrate the special role of organic cations in the inter-sheet assembly configuration,in sharp contrast with that of alkali/alkaline-earth ones.We propose that organic cations cause edge/face contact of the sheets,instead of the face/face contact,thus affording a house-of-cards structure.

Synthesis of Zeolitic Material on the Basis of Natural Raw Material Volcanic Ash in Presence of Tetraethylammonium Iodide

Zeolitic material as Na-mordenit (SiO2/Al2O3 = 10) was synthesized on the basis of natural raw material volcanic ash, in presence of organic components tetraetilamonium iodide (TEAI). The ash sample used in the laboratory experiments contains 67%, 56% SiO2 and 12.48% Al2O3, abundances. The reaction time as well as the influence of TEAI was studied in the zeolitic materials crystallization. The experiments were carried out under hydrothermal conditions, autogenic pressure and temperature of 220℃, as well as reaction time from 48 to 240 h. Products from this hydrothermal treatment were identified by the rentgenophase analysis methods on the apparatus of BRUKER D2 PHASER and weight-spectroscopic analysis method on the apparatus of ICP-MS Agilent 7700. Of the zeolitic material, the Na-mordenit zeolite was found to be the most effective for the retention of cations Pb2+, Zn2+ and Ba2+.

Effect of algal flocculation on dissolved organic matters using cationic starch modified soils

Modified soils（MSs） are being increasingly used as geo-engineering materials for the sedimentation removal of cyanobacterial blooms. Cationic starch（CS） has been tested as an effective soil modifier, but little is known about its potential impacts on the treated water.This study investigated dissolved organic matters in the bloom water after algal removal using cationic starch modified soils（CS-MSs）. Results showed that the dissolved organic carbon（DOC） could be decreased by CS-MS flocculation and the use of higher charge density CS yielded a greater DOC reduction. When CS with the charge density of 0.052, 0.102 and0.293 meq/g were used, DOC was decreased from 3.4 to 3.0, 2.3 and 1.7 mg/L, respectively.The excitation–emission matrix fluorescence spectroscopy and UV254 analysis indicated that CS-MS exhibits an ability to remove some soluble organics, which contributed to the DOC reduction. However, the use of low charge density CS posed a potential risk of DOC increase due to the high CS loading for effective algal removal. When CS with the charge density of 0.044 meq/g was used, DOC was increased from 3.4 to 3.9 mg/L. This study suggested, when CS-MS is used for cyanobacterial bloom removal, the content of dissolved organic matters in the treated water can be controlled by optimizing the charge density of CS. For the settled organic matters, other measures（e.g., capping treatments using oxygen loaded materials） should be jointly applied after algal flocculation.

Functional evidence that FGFR regulates MAPK signaling in organizer specification in the gastropod mollusk Lottia peitaihoensis

The D-quadrant organizer sets up the dorsal–ventral(DV)axis and regulates mesodermal development of spiralians.Studies have revealed an important role of mitogen-activated protein kinase(MAPK)signaling in organizer function,but the related molecules have not been fully revealed.The association between fibroblast growth factor receptor(FGFR)and MAPK signaling in regulating organizer specification has been established in the annelid Owenia fusiformis.Now,comparable studies in other spiralian phyla are required to decipher whether this organizer-inducing function of FGFR is prevalent in Spiralia.Here,we indicate that treatment with the FGFR inhibitor SU5402 resulted in deficiency of organizer specification in the mollusk Lottia peitaihoensis.Subsequently,the bone morphogenetic protein(BMP)signaling gradient and DV patterning were disrupted,suggesting the roles of FGFR in regulating organizer function.Changes in multiple aspects of organizer function(the morphology of vegetal blastomeres,BMP signaling gradient,expression of DV patterning markers,etc.)indicate that these developmental functions have different sensitivities to FGFR/MAPK signaling.Our results reveal a functional role of FGFR in organizer specification as well as DV patterning of Lottia embryos,which expands our knowledge of spiralian organizers.

Efficient and stable perovskite solar cells by build-inπ-columns and ionic interfaces in covalent organic frameworks

Perovskite solar cells(PSCs)have attracted much attention due to their rapidly increased power conversion efficiencies,however,their inherent poor long-term stability hinders their commercialization.The degradation of PSCs first comes from the degradation of hole transport materials(HTMs).Here,we report the construction of periodicπ-columnar arrays and ionic interfaces over the skeletons by introducing cationic covalent organic frameworks(C-COFs)to the HTM.Periodicπ-columnar arrays can optimize the charge transport ability and energy levels of the hole transport layer and suppress the degradation of HTM,and ionic interfaces over the skeletons can produce stronger electric dipole and electrostatic interactions,as well as higher charge densities.The C-COFs were designed and synthesized via Schiff base reaction by using 1,3,5-triformylphloroglucinol as a neutral knot and dimidium bromide as cationic linker.The neutral COFs(N-COFs)were also synthesized as a reference by using 3,8-diamino-6-phenylphenanthridine as neutral linker.PSCs with cationic COF exhibit the highest efficiency of 23.4%with excellent humidity and thermal stability.To the best of our knowledge,this is the highest efficiency among the meso-structured PSCs fabricated by a sequential process.

Hollow click-based porous organic polymers for heterogenization of [Ru（bpy）3]2＋ through electrostatic interactions

A facile approach for the heterogenization of transition metal catalysts using non-covalent interactions in hollow click-based porous organic polymers （H-CPPs） is presented. A catalytically active cationic species, [Ru（bpy）3]〉 （bpy = 2,2＇-bipyridyl）, was immobilized in H-CPPs via electrostatic interactions. The intrinsic properties of [Ru（bpy）3]〉 were well retained. The resulting Ru- containing hollow polymers exhibited excellent catalytic activity, enhanced stability, and good recyclability when used for the oxidative hydroxylation of 4-methoxyphenylboronic acid to 4-methoxyphenol under visible-light irradiation. The attractive catalytic performance mainly resulted from efficient mass transfer and the maintenance of the chemical properties of the cationic Ru complex in the H-CPPs.

Rational design of a cationic polymer network towards record high uptake of ^(99)TcO_(4)^(-)in nuclear waste

^(99)Tc is a long-lived radionuclide present in large amounts as TcO_(4)^(-)-anion in used nuclear fuel.Its removal from the waste stream is highly desirable because of its interference capability with actinide separation and its volatile nature during the nuclear waste vitrification process.Despite the progress achieved in the past few years,the design of anion-exchange materials with optimized Tc uptake property and improved stability under the extreme condition is still a research goal beneficial for reducing the volume of secondary radioactive solid waste generated during the waste partitioning process.However,their design philosophy remains elusive,with challenges coming from charge repulsion,steric hindrance,and insufficient reactive sites within the materials.Herein,we present a design philosophy of cationic polymer network materials for TcO_(4)^(-)separation by systematic precursor screening and structure prediction.This affords an optimized material,SCU-CPN-2(SCU=Soochow University),with extremely high positive charge density while maintaining high radiation resistance.SCU-CPN-2 exhibits a record high adsorption capacity1,467 mg/g towards the surrogate ReO_(4)^(-)compared to all anion-exchange materials reported up to date.In addition to ultrafast adsorption kinetics,SCU-CPN-2 has remarkable selectivity over nitrate and sulfate,and facile recyclability.