Changes In Solution Composition Research Articles

Change of solution composition during it migration through the sedimentary cover in the center of the modern hydrothermal system (Juan de Fuca Ridge, Pacific Ocean, Hole ODP 858B)

Change of solution composition during it migration through the sedimentary cover in the center of the modern hydrothermal system (Juan de Fuca Ridge, Pacific Ocean, Hole ODP 858B)

Redox cycling of straw-amended soil simultaneously increases iron oxide crystallinity and the content of highly disordered organo-iron(III) solids

Iron speciation in soils is influenced largely by its redox state, but the extent of and controls on Fe speciation during recurrent reduction and oxidation events are not fully understood. To investigate the effects of organic matter (OM) inputs and the frequency and duration of redox oscillations on soil Fe speciation, we conducted redox-oscillation experiments with topsoil from a Fluvisol mixed with rice straw (0, 10, 50 g/kg organic carbon, OC). The soil was initially dominated by short-range ordered (SRO) Fe(III) solids and subjected to 14- and 28-day reduction–oxidation cycles for 112 days, with the time spent under anoxic and oxic conditions maintained at 6:1. Reduction was initiated by flooding reactors with artificial river water. To simulate leaching conditions, soil re-oxidation was achieved by air-drying soil after removal of reacted solutions. Fresh river water was then added for each new redox cycle. We monitored changes in solution composition (Eh, pH, Fe(II), total Fe, OC, and Si) and assessed changes of solid-phase Fe speciation by selective extractions, X-ray absorption spectroscopy, and 57Fe Mössbauer spectroscopy. Dissolved OC and Fe increased with increasing straw addition, but decreased in each treatment through consecutive reduction intervals. Release rates of dissolved Fe and OC were highly correlated, implying that microbial reduction of soil Fe(III) solids was fostered by straw amendments. Reduction-induced losses of OC and Fe from straw amended soil were amplified at high redox frequency. Ferrous Fe did not detectably accumulate in the solid phase upon repeated soil oxidation. Although Fe(III)-poor phyllosilicates gained in relative importance in redox-cycled soils, their fraction was hardly affected during redox cycling. Instead, straw additions led to an enhanced depletion of ferrihydrite during soil redox cycling and a relative enrichment of highly disordered Fe(III) species [‘very SRO (vSRO) Fe(III) solids’], which remained only partially ordered in 5-K Mössbauer spectra and likely consisted predominantly of polynuclear organic Fe complexes. The depletion of ferrihydrite in straw-amended soils after 112 days was greater in the 14-day cycle than in the 28-day cycle experiment and accompanied by a less pronounced enrichment of vSRO Fe(III) solids. The crystallinity of distinct Fe oxides (ferrihydrite, lepidocrocite, and hematite) increased during soil redox cycling especially in straw-amended soils, but without noticeable ferrihydrite conversion into crystalline Fe oxides. The increase in the crystallinity of distinct Fe oxides after 112 days was greater at low redox frequency in straw-free soil, however this frequency effect was suppressed by straw additions. Longer soil redox cycling (112 vs. 56 days) increased the crystallinity of distinct Fe oxides, which was most pronounced at high straw levels and low redox frequency. Our results imply that redox changes in SRO Fe oxide- and OM-rich soils can cause a relative enrichment of more crystalline Fe oxides, while still maintaining a pool of vSRO Fe(III) solids. We conclude that soil redox oscillations can lead to divergent transformation pathways of Fe oxides, which concomitantly increase bulk Fe-oxide crystallinity and generate increasing fractions of highly disordered Fe(III) solids on comparatively short time scales. In addition, our study suggests that faster redox cycling in soils with ample electron donor supply and water leaching leads to higher element exports (e.g., OC, metal(loid)s) from soil due to weekly redox pulsing than more slowly alternating redox conditions.

Estimating the corrosion rate of stainless steel R-SUS304ULC in nitric acid media under concentrating operation

The amount of corrosion of the austenitic stainless steel was evaluated considering the changes in solution composition and boiling during actual concentration operations. Austenitic stainless steel R-SUS304ULC is the structural material of the highly radioactive liquid waste concentrator in Japanese spent fuel reprocessing plant, which treats highly corrosive nitric acid solutions during enrichment operations. The study results show that it is necessary to focus on nitric acid concentrations, oxidizing metal ion concentrations, and decompression boiling as factors that accelerate the corrosion rate of stainless steel because of cathodic reaction activation.

A multi-species reactive transport model based on gas-ion-solid phase interaction for the carbonation of cement-based materials

This study presents a reactive transport modelling framework for understanding carbonation processes through pore solution composition, phase assemblage changes in cement-based materials, and pore solution composition changes on steel corrosion. The study emphasizes the significance of considering pore structure changes on mass transport and utilizing a surface complexation model for predicting changes in pore solution composition and comprehending its influence on steel corrosion. A clear enrichment in sodium and potassium content in carbonated regions is observed upon carbonation, which leads to a decrease in alkali concentration in the pore solution, and alkali ions are transported toward the carbonated zone. Simultaneously, the opposite behaviour is observed for both the sulphur and chloride content. The increase in the concentration of sulphur and chloride in the pore solution was observed upon the decomposition of the solid phase. Calcium ions are transported to the carbonated zone, further increasing calcite formation near the exposed surface.

Neogene drainage reorganization of Longzhong Basin driven by growth of the northeastern Tibetan Plateau: A Sr isotope hydrological perspective

AbstractThe Tibetan Plateau uplift has significantly influenced Asian geomorphic and climate patterns. Drainage evolution across the plateau and its surroundings as the consequence of such changes in landscape and climate provides an opportunity to understand the growth of the Tibetan Plateau. However, the evolution history of major drainage areas around the Tibetan Plateau is largely unknown. Here, we reconstructed the evolution of drainage patterns of the Cenozoic Longzhong Basin in the northeastern Tibetan Plateau since the India–Asia collision using palaeo‐water solute 87Sr/86Sr ratio records from its subbasins. Higher solute 87Sr/86Sr ratios of the Lanzhou and Xining Basins and their consistent temporal variations before ca. 22 Ma as well as lower solute 87Sr/86Sr ratios in the Linxia Basin collectively indicate a relatively steady drainage pattern of the integrated Longzhong Basin. A diverse evolution of the solute 87Sr/86Sr ratio in the Lanzhou and Xining Basins after ca. 22 Ma suggests that there was a drainage reorganization, characterized by the division of one into multiple catchment centres, in response to the growth of the northeastern Tibetan Plateau. Subsequently, the identical solute 87Sr/86Sr ratios in the Lanzhou and Xining Basins were further approached at ca. 16 Ma, and the rise in the solute 87Sr/86Sr ratios of the Linxia and Tianshui Basins occurred at ca. 9–8 Ma, indicating two subsequent changes in solute composition induced by the middle Miocene uplift and late Miocene dust expansion, respectively. Our reconstructions of Cenozoic hydrological evolution in the Longzhong Basin indicate accelerated basin segmentation and drainage adjustment with solute change in response to the growth of the northeastern Tibetan Plateau during the Neogene.

植物由来フォトクロミック溶液の溶媒組成変化とフォトクロミック性能の関係

A solution composed of 3-deoxyanthocyanidin extracted from sorghum shell, a weakly acidic buffer solution, and dipropylene glycol showed photochromism. For the industrial use of this natural photochromic dye, solidification or pigmentation is necessary. However, there is a concern that the photochromic performance may deteriorate due to the change in solution composition through the process. In this study, we investigated the effect of composition shifts of the dye solution, namely solvent volatilization, water loading, and acid, base or polyvalent cation contamination on the photochromic performance.

Intramolecular and intermolecular effects of aromatic sticker residue strength on intrinsically disordered protein regions.

The formation of biomolecular condensates plays critical roles in cellular life and is implicated in various diseases. Condensate formation is often driven by multivalent interactions between aromatic “sticker” residues embedded between non-interacting “spacers” in intrinsically disordered protein regions (IDRs). One underappreciated factor, however, is that homotypic stickers such as aromatic residues can interact not only intermolecularly but also intramolecularly. This is especially important when considering the high “effective concentration” of intrachain stickers. How and under what conditions can intermolecular sticker-sticker interactions outcompete intramolecular sticker-sticker interactions? To investigate these questions, we examine minimal IDR constructs containing Gly-Ser repeat spacers and aromatic stickers of varying strengths. We combine atomistic and coarse-grained simulations with ensemble FRET and small-angle X-ray scattering data to compare the monomeric ensembles of these constructs against their tendency to form intermolecular interactions. We further show how this competition is modulated by changes in solution composition. Our experiments reveal how sticker strength, spacer length, and the chemical environment work together to determine the winner of the competition between inter- and intramolecular interactions.

Interfacial and rheological properties of long-lived foams stabilized by rice proteins complexed to transition metal ions in the presence of alkyl polyglycoside

HypothesisTransition-metal coordination complexes are hopeful to make advanced structural materials, since the metal-coordination bonds, unlike typical covalent bonds, can regenerate after rupture, allowing for dynamic, tunable, and reversible mechanical characteristics. Integration of metal-coordinate crosslinking in foam material has rarely been reported. ExperimentsWe developed the hydrolyzed rice proteins (HRP) as the building block for amphiphilic transition-metal coordination complexes that could be used to make long-lived foams with high yield stress. Surface properties of the foaming solution were determined using equilibrium and dynamic tensiometers. Structural information of aggregates in the foaming solution was detected by small-angle X-ray scattering (SAXS) and Cryo-Tem. Visualization of liquid flow in the interfacial liquid film was studied by the reflective optical interference technique. Rheological response of liquid foam was characterized by a rheometer with amplitude-sweep and frequency-sweep modes. FindingsIn the presence of transition metal ions, HRP formed a mechanically strong rigid film. In the absence of transition metal ions or the addition of alkyl polyglycoside (APG), HRP was desorbed to produce a mobile film with a detergent state. The two interfacial states could be actively switched based on facile changes in bulk solution composition (metal ions or alkyl glycoside or chelating agent), and the switching between the two states led to the formation of extremely stable foam with high yield stress or the collapse of foam with a significant decrease in yield limit. The transition-metal coordination complexes adsorbed on the surface of the liquid film could increase the elastic modulus of liquid foam by more than an order of magnitude without increasing the viscosity of the foaming solution. We further revealed the origin of foam stability/instability and used other well-characterized proteins to prepare transition-metal coordination complexes to make long-lived foams. The cases described in this work illustrate the universal nature of the strategy, which in principle can be extended to many types of protein.

Quantifying antisite defect concentrations in yttrium aluminum garnet by high-precision density analysis

Quantifying the nature and density of lattice defects in high-quality crystals is often difficult or impossible with commonly employed material characterization techniques. In many cases, even the density of intentionally doped impurities present in a grown crystal must be inferred indirectly using methods such as mapping spatial variations in crystal properties or, when the defects are optically active, interpreting optical absorption with imprecisely known oscillator strengths. In this work we explore gravimetric techniques to obtain absolute defect densities in crystals, a powerful approach often overlooked in modern materials science. A hydrostatic weighing apparatus based on Archimedes’ principle was constructed, tested, and refined to enable high-precision density measurements of small crystal samples. Application of this system is illustrated by determining the density of Yttrium Aluminum Garnet (YAG) relative to a high-purity silicon crystal density reference, minimizing traditional difficulties in correcting for the variations in surface tension and the water and air density due to small changes in ambient temperature, pressure, and solution composition. This method, using a relatively simple apparatus and small samples, is effective in measuring the intrinsic concentration of Y–Al antisite lattice defects in YAG, agreeing with results from far more elaborate high-resolution optical laser spectroscopy at cryogenic temperatures. Furthermore, we quantitatively analyze the effects of several potential sources for error, including natural variations in isotope distributions, residual surface contamination, and ambient temperature or pressure variations. Subsequently, we find that the density analysis method is a promising technique for characterizing new and modified materials being developed for applications ranging from solid-state lasers and scintillators to quantum information.

Features of interaction in the water-rock-CO2 system during the implementation of CCUS projects (on the example of chalk reservoirs in the Arctic sector of Western Siberia)

The paper considers approaches to the analysis of physicochemical interactions in the water-rock-carbon dioxide system, solved by mathematical modeling and aimed at analyzing the behavior of this system during CO burial in the Cretaceous aquifers of the Arctic sector of Western Siberia. The problem was solved using the HydroGeo software package, which makes it possible to analyze the change in the chemical composition of solutions, the forms of migration of the main components of groundwater, as well as mineral equilibria both at the time of carbon dioxide invasion and when the solution reaches equilibrium.

Rainfall partitioning and associated chemical alteration in three subtropical urban tree species

Rainwater is altered hydrologically and chemically as it passes through tree canopies to reach the soil surface, but this aspect of urban forest ecosystems has received less attention than that of natural ecosystems. Hydrological partitioning and changes in solute composition of rainfall were examined in an urban forest within Guangzhou city, in southern China, with reference to three typical subtropical urban tree species (Roystonea regia, Ficus microcarpa, and Lagerstroemia speciosa) with large but morphologically distinct canopies. Three components of rainfall, namely throughfall, stemflow, and interception, were measured and sampled from September 2018 to September 2019. A canopy budget model was used for estimating the contribution of canopy exchange and dry deposition to net rainfall (throughfall + stemflow) solute flux. Being a palm, R. regia recorded the highest percentages of throughfall (72.60%) and stemflow (8.68%) whereas interception was higher in F. microcarpa (33.48%) and L. speciosa (30.54%). The concentrations of almost all the solutes (Ca2+, K+, Na+, Mg2+, Cl−, NO3−, and SO42−) in throughfall and stemflow were higher than those in rainfall, suggesting that water was enriched with these solutes as a result of passing through the canopy. The model of canopy budget also showed that whereas all the three species were similar in terms of the leaching of macronutrient cations, the species differed in term of anions: whereas R. regia and L. speciosa generally absorbed or retained anions on foliage, twigs, or trunks, F. microcarpa leached Cl− and NO3− (presumably because of its unique aerial root). These results can inform the design of urban forests. For example, the lack of NO3− uptake by F. microcarpa suggests that it would be less suitable for mitigating the problems of N deposition which are significant in southern China than the other two species; on other hand, the rainfall partitioning and canopy exchange characteristics of L. speciosa make it more suitable for intercepting rainwater as well as for alleviating the problem of N deposition. The findings of this study therefore have significant implications for the selection of urban tree species in similar subtropical regions worldwide.

Global View and Trends in Electrospun Nanofiber Membranes for Particulate Matter Filtration: A Review

AbstractNumerous experimental works for particulate matter (PM) filtration by electrospun nanofiber membranes (ESNFMs) are published in the last 10 years (2010–2021). Organizing and comparing the large amount of the available information to identify the best trends constitutes a big challenge. This review classifies all kinds of ESNFMs considering their physical, chemical, or electrical characteristics. All of them are obtained by modifying several parameters during a specific stage associated to the electrospinning process (ES). In this review, each of these stages is considered a "moment” as a particular instant in time. According to that, three modifications are made: Moment 1—before ES, which refers to changes in polymeric solution composition; moment 2—during ES, which refers to modifying parameters while ES is performed; and moment 3—after ES, which involves applying post‐treatments directly on the membrane. After classifying all kinds of filters by moments, a detailed comparison of ESNFMs with the highest quality factors for PM0.3 is presented, finding out the best trends and comparing their main filtration parameters as well, where the most promising ones correspond to charged and nanofiber/nets membranes, due to their high capture efficiencies (>95%) while maintaining low pressure drops (<100 Pa).

Appropriate NH4 +/NO3 - Ratio Triggers Plant Growth and Nutrient Uptake of Flowering Chinese Cabbage by Optimizing the pH Value of Nutrient Solution.

Compared with sole nitrogen (N), the nutrition mixture of ammonium (NH4+) and nitrate (NO3–) is known to better improve crop yield and quality. However, the mechanism underlying this improvement remains unclear. In the present study, we analyzed the changes in nutrient solution composition, content of different N forms in plant tissues and exudates, and expression of plasma membrane (PM) H+-ATPase genes (HAs) under different NH4+/NO3– ratios (0/100, 10/90, 25/75, 50/50 as control, T1, T2, and T3) in flowering Chinese cabbage. We observed that compared with the control, T1 and T2 increased the economical yield of flowering Chinese cabbage by 1.26- and 1.54-fold, respectively, whereas T3 significantly reduced plant yield. Compared with the control, T1–T3 significantly reduced the NO3– content and increased the NH4+, amino acid, and soluble protein contents of flowering Chinese cabbage to varying extents. T2 significantly increased the N use efficiency (NUE), whereas T3 significantly decreased it to only being 70.25% of that of the control. Owing to the difference in N absorption and utilization among seedlings, the pH value of the nutrient solution differed under different NH4+/NO3– ratios. At harvest, the pH value of T2 was 5.8; in the control and T1, it was approximately 8.0, and in T3 it was only 3.6. We speculated that appropriate NH4+/NO3– ratios may improve N absorption and assimilation and thus promote the growth of flowering Chinese cabbage, owing to the suitable pH value. On the contrary, addition of excessive NH4+ may induce rhizosphere acidification and ammonia toxicity, causing plant growth inhibition. We further analyzed the transcription of PM H+-ATPase genes (HAs). HA1 and HA7 transcription in roots was significantly down-regulated by the addition of the mixture of NH4+ and NO3–, whereas the transcription of HA2, HA9 in roots and HA7, HA8, and HA10 in leaves was sharply up-regulated by the addition of the mixture; the transcription of HA3 was mainly enhanced by the highest ratio of NH4+/NO3–. Our results provide valuable information about the effects of treatments with different NH4+/NO3– ratios on plant growth and N uptake and utilization.

Revealing the Hidden Sensitivity of Intrinsically Disordered Proteins to their Chemical Environment.

Intrinsically disordered protein-regions (IDRs) make up roughly 30% of the human proteome and are central to a wide range of biological processes. Given a lack of persistent tertiary structure, all residues in IDRs are, to some extent, solvent exposed. This extensive surface area, coupled with the absence of strong intramolecular contacts, makes IDRs inherently sensitive to their chemical environment. We report a combined experimental, computational, and analytical framework for high-throughput characterization of IDR sensitivity. Our framework reveals that IDRs can expand or compact in response to changes in their solution environment. Importantly, the direction and magnitude of conformational change depend on both protein sequence and cosolute identity. For example, some solutes such as short polyethylene glycol chains exert an expanding effect on some IDRs and a compacting effect on others. Despite this complex behavior, we can rationally interpret IDR responsiveness to solution composition changes using relatively simple polymer models. Our results imply that solution-responsive IDRs are ubiquitous and can provide an additional layer of regulation to biological systems.

Temperature dependence of gypsum dissolution rates

The reaction kinetics of gypsum dissolution are important for establishing an optimum gypsum content in portland cement. In this paper, the temperature dependence of dissolution rates was measured by tracking changes in solution composition and surface area with time. The rate coefficient increases with temperature and the specific surface area decreases with ongoing dissolution. The dissolution rate depends on the solution's saturation index to an exponent of approximately 1.5. The apparent activation enthalpy is approximately 34 kJ mol−1, independent of saturation index and surface area, suggesting that dissolution is controlled by surface reaction rather than mass transport. The activation enthalpy is interpreted as the energy required to cooperatively break all the ionic bonds at occupied kink sites of the gypsum-water interface. Activation enthalpies similar in magnitude have been reported for other calcium salts, which may indicate that all of these processes involve breaking ionic calcium-oxygen bonds of similar strengths.

Theoretical Analysis of Changes in the Solution Composition during Anodic Electrolysis of Bromide

The changes in indicator-electrode potential and (quasi)equilibrium solution composition in the anodic compartment of a model electrolyzer initially filled with aqueous electrolyte containing 0.5 M concentration of bromide anions are calculated under the condition that pH 2 is maintained constant in this compartment. The theoretical analysis is carried out for three different hypotheses concerning the possible depth of electrolysis and the nature of processes involved: (1) no bromine compounds with positive degree of oxidation are formed; (2) bromine compounds with the degree of oxidation not higher than +1 are formed; (3) the process can involve the formation of both bromate ions and bromine compounds with the lower degrees of oxidation ($${\text{Br}}_{{\text{3}}}^{ - },$$$${\text{Br}}_{{\text{5}}}^{ - },$$ Br2, BrO–, HBrO) in solution as well as the liquid phase of bromine $$\left( {{\text{Br}}_{{\text{2}}}^{{{\text{liq}}}}} \right).$$ All electrochemical and chemical reactions involving bromine-containing species taken into account within the framework of hypotheses of system evolution 1, 2, and 3 are assumed to be (quasi)equilibrium, and the electric current through the cell separator is assumed to be provided by supporting electrolyte ions. Methods are proposed for experimental determination of the version of evolution of Br-containing anolyte during electrolysis.

Polyelectrolyte Conformation Controlled by a Trivalent-Rich Ion Jacket.

The configuration of charged polymers is heavily dependent on interactions with surrounding salt ions, typically manifesting as a sensitivity to the bulk ionic strength. Here, we use single-molecule mechanical measurements to show that a charged polysaccharide, hyaluronic acid, shows a surprising regime of insensitivity to ionic strength in the presence of trivalent ions. Using simulations and theory, we propose that this is caused by the formation of a "jacket" of ions, tightly associated with the polymer, whose charge (and thus effect on configuration) is robust against changes in solution composition.

An empirical rate law for gypsum powder dissolution

The dissolution rates, normalized by surface area, of two different gypsum powders in aqueous solutions were measured by tracking changes in solution composition as a function of time in a continuously stirred batch reactor. The powders were classified into different size ranges to observe the influence of particle coarseness on dissolution kinetics. Changes in solid surface area during the experiment were modeled as a function of mass loss by measuring the specific surface areas of the powders before and after the experiments. Contrary to the implicit assumption in several previous studies, the total powder surface area increases, typically by a factor of two, prior to decreasing with ongoing dissolution. This phenomenon therefore has a significant influence, up to 50%, on the surface area-normalized rate. The initial solution composition was set to one of several prescribed saturation states so that an empirical rate law could be inferred over a wide range of saturations. The rate coefficient for both types of gypsum depended on size, being lower for coarser particles. Other than the difference in rate coefficients, the dissolution rate of both sources of gypsum can be described well by the same mathematical function of solution saturation, at least to within the uncertainty in the measurements. Data from previous studies of gypsum dissolution appear to follow approximately the same dependence on particle size as observed in this study.

Effect of Ammonium Chloride on the Efficiency with Which Copper Sulfate Activates Marmatite: Change in Solution Composition and Regulation of Surface Composition

Zinc sulfide minerals are the primary choice for zinc extraction and marmatite is one of the two most common zinc sulphide minerals (sphalerite and marmatite), therefore it is of great significance to study and optimize the flotation of marmatite. To improve the activation of copper sulfate on marmatite, a method involving the addition of ammonium chloride is devised. The method has been proven to be an effective way of improving the activation efficiency of copper sulfate towards marmatite under alkaline conditions. The strengthening mechanism was studied using micro-flotation, adsorption test, X-ray photoelectron spectroscopy, and by analyzing changes in solution composition. Flotation test results show that the activation effect of the copper sulfate towards marmatite is enhanced with the addition of ammonium chloride. According to the results of the adsorption measurements and X-ray photoelectron spectroscopy analysis, when the marmatite surface is activated using copper sulfate with added ammonia chloride, it adsorbs more copper sulfide and less copper hydroxide and zinc hydroxide. These changes in surface composition are believed to occur via the following process: NH3(aq) promotes the dissolution of zinc hydroxide and then facilitates the conversion of surface copper hydroxide to copper sulfide. In addition, the occurrence of Cu(NH3)n2+ can promote the adsorption of copper ions (Cu2+ can be stored as Cu(NH3)n2+ via complexation, and then, when the concentration of copper ions decreases, Cu2+ can be released through the decompositionof Cu(NH3)n2+. Hence, the copper ion concentration can be maintained and this can facilitate the adsorption of Cu2+ on marmatite). Based on a comprehensive analysis of all our results, we propose that adding ammonium chloride to the copper sulfate changes the solution components (i.e., the presence of NH3(aq) and Cu(NH3)n2+) and then regulates the surface composition of marmatite. The change in surface composition improves the hydrophobicity of mineral surface and this leads to an improvement in activation of marmatite.

Controlling Nucleation and Growth of Metal Halide Perovskite Thin Films for High-Efficiency Perovskite Solar Cells.

Metal halide perovskite thin films can be crystallized via a broad range of solution-based routes. However, the quality of the final films is strongly dependent upon small changes in solution composition and processing parameters. Here, this study demonstrates that a fractional substitution of PbCl2 with PbI2 in the 3CH3 NH3 I:PbCl2 mixed-halide starting solution has a profound influence upon the ensuing thin-film crystallization. The presence of PbI2 in the precursor induces a uniform distribution of regular quadrilateral-shaped CH3 NH3 PbI3 perovskite crystals in as-cast films, which subsequently grow to form pinhole-free perovskite films with highly crystalline domains. With this new formulation of 3CH3 NH3 I:0.98PbCl2 :0.02PbI2 , this study achieves a 19.1% current-voltage measured power conversion efficiency and a 17.2% stabilized power output in regular planar heterojunction solar cells.