Current Efficiency Research Articles

Primary-Side ZVS PWM Resonant Converter With Near-Zero-Ripple Input Current and High Efficiency for Fuel Cell Applications

Primary-Side ZVS PWM Resonant Converter With Near-Zero-Ripple Input Current and High Efficiency for Fuel Cell Applications

Highly Stable Silver Nanowire Plasmonic Electrodes for Flexible Polymer Light-Emitting Devices.

Silver nanowire (AgNW) transparent electrodes are considered as a promising candidate for applications in flexible optoelectronic devices. However, it remains a great challenge to obtain flexible AgNW electrodes with excellent optoelectrical properties and mechanical flexibility. Here, highly stable Ag nanoparticle (AgNP)-enhanced plasmonic AgNW electrodes are demonstrated via the controllable in situ growth of AgNPs at the AgNW junctions and introduction of an l-histidine (l-His) wrapping layer. The flexible transparent electrodes of AgNW-AgNP/l-His possess a low sheet resistance (Rsh) of ∼17.5 Ω sq-1, a high transmittance of ∼92.5% (550 nm), and a robust mechanical stability (100,000 bending cycles). Benefiting from plasmon-coupling effects, flexible polymer light-emitting devices (FPLEDs) with AgNW-AgNP/l-His electrodes present a current efficiency (CE) of ∼14.8 cd A-1 and an external quantum efficiency (EQE) of ∼5.6%, constituting ∼80% and ∼75% increases compared to those of the reference devices with AgNW electrodes, respectively. Additionally, the laminated flexible transparent PLEDs (FT-PLEDs) are demonstrated by integrating polydimethylsiloxane/AgNW-AgNP anodes by a soft lamination process. The FT-PLEDs present a CE of ∼7.1 cd A-1 (cathode side: ∼3.9 cd A-1; anode side: ∼3.2 cd A-1) and an EQE of ∼2.7% (cathode side: ∼1.5%; anode side: ∼1.2%). Furthermore, the FPLEDs and FT-PLEDs exhibit robust mechanical durability, maintaining ∼89% and ∼86% of their initial luminance after 1000 bending cycles at a bending radius of 2 mm, respectively. This work opens up a new avenue for the development of high performance and stable flexible optoelectronic devices.

Electrochemically regulating COD/TN ratio of aged landfill leachate via rapid chlorine-mediated ammonia oxidation with RuO2-IrO2/Ti anode

Electrochemical oxidation process was employed to regulate the ratio of chemical oxygen demand to total nitrogen (COD/TN ratio) of aged landfill leachate, aiming to meet the requirement of biological treatment. The results indicate that the ammonia nitrogen can be rapidly removed through electrogenerated chlorine radicals over a typical chlorine evolution RuO2-IrO2/Ti anode. The increased input current and decreased flow rate are beneficial to COD/TN ratio improvement, and COD/TN ratio can be increased to more than 16 at 1000 mA (input current) and 0.3 L/h (flow rate). According to the obtained experimental data, we present a strategy for COD/TN ratio increase: (i) determining the COD/TN ratio balance coefficient (B) of aged landfill leachate, and selecting the anode with COD/TN ratio adjustment coefficient (TN) >B, where TN represents the ability to regulate COD/TN ratio, and B represents the specific TN to keep the same COD/TN ratio; (ii) performing the wastewater treatment experiments at different control parameters during electrochemical process; (iii) calculating the k of control parameter sensitivity curves to achieve different tolerance abilities, and further preferentially regulating the reaction process to high average current efficiency (ACE) of ammonia nitrogen and low ACE of COD. This work validates that the electrochemical process can increase the COD/TN ratio together with enhancing the biodegradability of such refractory wastewater, and also provides an effective tool for regulation of the COD/TN ratio via complete ammonia oxidation.

Direct Electrooxidation of Ammonia-Enriched Wastewater Using a Bipolar Membrane-Integrated Electrolytic Cell

The treatment of reject water containing concentrated ammonia and non-biodegradable organics is a challenging task in wastewater treatment plants. To address this problem, we propose a novel process consisting of a selective ammonium-exchange resin and an ammonia electrooxidation reaction (AmER-AOR). Because an alkaline condition is essential for direct ammonia oxidation, the use of a bipolar membrane (BPM) was helpful. Nonetheless, an initial pH of 13 and KOH addition were required to maintain a high alkalinity for the complete elimination of ammonia. The linear sweep voltammogram elucidated the high pH requirement and ammonia oxidation promotion. When the current density varied from 30 to 80 mA cm−2, 60 mA cm−2 showed the highest current efficiency (30.39%) and the lowest specific energy demand (95.3 kWh/kg-N), indicating the most energy-effective condition. Increasing the initial concentration of ammonia from 0.1 M to 0.5 M improved the current efficiency (51.57%), demonstrating an additional energy-effective strategy for the AmER-AOR. The energy efficiency of pure H2 production in the cathodic chamber was 30%. To estimate the viability for practical applications, reject water collected from a local wastewater treatment plant was applied in the AmER-AOR. Notably, no significant difference in the ammonia removal rate was observed with synthetic wastewater. To the best of our knowledge, this is the first study that employs a BPM as a separator and OH− supplier for direct ammonia oxidation. Our findings reveal that the AmER-AOR with a BPM has promising practical applicability in the treatment of reject water and energy production.

Numerical simulation of deep ultraviolet LED, micro-LED, and nano-LED with different emission wavelengths based on FDTD

The current low external quantum efficiency (EQE) of deep ultraviolet (DUV) LEDs and micro-LEDs is largely attributed to their low light extraction efficiency (LEE). To address this issue and increase the LEE of DUV devices, various strategies such as reducing size, modifying surface with nanostructures and roughening substrates have been proposed. While some studies have investigated the effects of nanopillar and size on DUV LED, there remains a lack of systematic research on the LEE enhancement mechanism across different wavelengths and sizes of DUV LEDs, micro-LEDs, and nano-LEDs. Therefore, in this study, we employed the numerical simulation method to explore the LEE, near-field intensity distribution, and far-field light intensity distribution from various angles for DUV LEDs, micro-LEDs, and nano-LEDs with wavelengths of 255 nm, 260 nm, and 275 nm, respectively. Our findings reveal a significant improvement in the LEE of DUV nano-LEDs and micro-LEDs, accompanied by reduced divergence angles. Moreover, we observe that longer wavelengths correspond to higher LEE values for devices with similar size. This enhancement in LEE is attributed to factors such as increased sidewall emission and reduced p-GaN absorption. Our investigation indicates that as the size of the DUV device decreases, the sidewall LEE for both transverse electric (TE) and transverse magnetic (TM) modes increases, with TM mode exhibiting a larger enhancement. This enhancement is mainly attributed to the reduction of total reflection within the DUV LEDs and micro-LEDs resulting from size reduction. Despite this, TE mode remains the main contributor to overall LEE. Additionally, our study reveals a reduction in p-GaN absorption of DUV light with decreasing device size, further contributing to the enhancement of LEE in DUV micro-LEDs and nano-LEDs. The increased LEE and reduced divergence angles of small-size DUV micro-LEDs and nano-LEDs not only promote lower power consumption but also enable easier optical system coupling. Consequently, these advancements have significant potential in optical wireless communication, charge management and high-precision lithography.

Rare Earth Chlorides in Low-Hydration Magnesium Chloride Electrolysis: Mechanistic Insights

During the molten salt electrolysis of magnesium production, water in the magnesium chloride (MgCl2) feedstock poses significant interference, reducing the current efficiency. Employing rare earth chlorides (RECl3) to assist in dehydrating MgCl2 and producing Mg-RE master alloys emerges as an effective strategy. This study investigated the transformation process in the hydrolysis reaction of low-hydrate MgCl2 within the molten salt, examining the electrochemical activity of its hydrolysis products using Cyclic voltammetry (CV). Additionally, a thermodynamic analysis of the reaction between hydrolyzate MgO and RECl3 was performed at electrolysis temperatures. By integrating CV and Square wave voltammetry (SWV) with X-ray diffraction (XRD) analysis, the study explored the alterations in the electrochemically active components of the molten salt system following the addition of RECl3 to the KCl-NaCl molten salt containing MgO.

Enhancing CdSe/ZnS Quantum-Dot Light-Emitting Diode Performance: The Impact of Thermal Treatment Atmospheres on Fabrication Processes

We explored the thermal treatment impact on the performance of quantum-dot light-emitting diodes (QLEDs). The QLEDs comprised multiple layers: a 2.2-μm thick epoxy buffer layer; a bottom cathode composed of 12-nm MoOx/10-nm Ag/12-nm MoOx; a 20-nm ZnO electron transporting layer (ETL); a 10-nm CdSe/ZnS quantum dot light emission layer (EML); a 40-nm 4,4′,4″-Tris(carbazol-9-yl) triphenylamine hole transporting layer; a 10-nm WOx hole injection layer; and a 100-nm Ag top anode. We applied thermal treatments to the cathode, ETL, and EML separately to assess their effects on the QLEDs. Additionally, we evaluated the impact of the thermal treatment atmosphere. Vacuum thermal treatment on the cathode and EML resulted in minor improvements in QLED performance, whereas treatment of the ETL led to a decline in performance. In contrast, air thermal treatment on the cathode and EML decreased QLED performance but significantly improved it by 15% in current efficiency when applied to the ETL. The performance differences attributable to the thermal treatment atmosphere are likely due to ligand removal and oxidation processes, facilitated by thermal energy and oxygen. Our study highlights that air thermal treatment on the ETL substantially improves QLED performance, offering crucial insights into the significance of thermal treatment in QLED development.

Fabrication of Tin and Zinc Gas Diffusion Electrodes for Electrochemical Reduction of Carbon Dioxide

This study explores the electrochemical reduction of carbon dioxide (CO2) using tin (Sn) and zinc (Zn) catalyst-loaded gas diffusion electrodes (GDEs). The research explores the influence of electrolytic potential and catalyst loading on the efficiency of CO2 conversion to valuable chemicals, specifically formic acid and carbon monoxide. The best Sn loading for Sn-loaded GDEs, according to the morphological study, is 7 mg.cm-2, which results in higher current density (0.33 mA.cm-2) and current efficiency (36%). An electrolytic potential of -1.3 V Vs. Ag/AgCl is identified as optimal for Sn GDEs, offering a balance between high current efficiency (35%) and controlled current density. For Zn-loaded GDEs, an optimal loading of 5 mg.cm²- yields the highest current efficiency of 19.4% and a peak current density of 0.28 mA.cm²- at an electrolytic potential of -1.55 V Vs. Ag/AgCl, in addition to highlighting the crucial role that catalyst loading and electrolytic potential play in enhancing CO2 reduction efficiency, this research offers insightful information for environmentally friendly CO2 conversion technology.

Pilot-scale study of membrane-coated cathodes: Achieving high cathodic efficiency and outstanding stability in chlorate electrolysis

Sodium chlorate (NaClO3) is primarily used for producing chlorine dioxide, an environmentally friendly bleaching agent for pulp. Currently, dichromate is used as an electrolyte additive in the chlorate process where it has several functions, but due to health and environmental risks associated with chromate, there is a need for a less toxic alternative. In the present study, we prepared a membrane-coated cathode as a substitute for chromium(VI), to keep a high current efficiency in chlorate electrolysis. This electrode employed an industrially relevant electrode with active catalysts as the substrate and a thin layer of ion exchange polymer as the coating. The coating effectively blocked anions such as ClO− and ClO3− from reaching the cathode, thereby suppressing cathodic side reactions. We conducted a series of electrochemical characterizations on the membrane-coated cathodes with varying coating thickness and tested them in a pilot-scale setup for efficiency and stability under industrial testing conditions.

Monitoring Photo-Fenton and Photo-Electro-Fenton process of contaminants emerging concern by a gas diffusion electrode using Ca10-xFex-yWy(PO4)6(OH)2 nanoparticles as heterogeneous catalyst

The catalytic performance of modified hydroxyapatite nanoparticles, Ca10-xFex-yWy(PO4)6(OH)2, was applied for the degradation of methylene blue (MB), fast green FCF (FG) and norfloxacin (NOR). XPS analysis pointed to the successful partial replacement of Ca by Fe. Under photo-electro-Fenton process, the catalyst Ca4FeII1·92W0·08FeIII4(PO4)6(OH)2 was combined with UVC radiation and electrogenerated H2O2 in a Printex L6 carbon-based gas diffusion electrode. The application of only 10 mA cm−2 resulted in 100% discoloration of MB and FG dyes in 50 min of treatment at pH 2.5, 7.0 and 9.0. The proposed treatment mechanism yielded maximum TOC removal of ∼80% and high mineralization current efficiency of ∼64%. Complete degradation of NOR was obtained in 40 min, and high mineralization of ∼86% was recorded after 240 min of treatment. Responses obtained from LC-ESI-MS/MS are in line with the theoretical Fukui indices and the ECOSAR data. The study enabled us to predict the main degradation route and the acute and chronic toxicity of the by-products formed during the contaminants degradation.

Efficient and durable iridium-doped SnO2 anode for reactive chlorine species-mediated urine wastewater treatment

The prevalence of nitrogen pollutants in urine wastewater has become a pressing environmental issue. Among various methods for addressing this concern, electrochemical oxidation processes that generate reactive chlorine species (RCS) from chloride ions commonly found in urine wastewater stand out as a promising approach. Despite the exploration of diverse anode materials, existing options still suffer from low selectivity in RCS generation, poor stability, and considerable energy consumption. In this study, we synthesized iridium-doped tin oxide (Ir-SnO2) as an efficient, durable, and energy-conserving anode and systematically evaluated its electrochemical activity for RCS-mediated removal of nitrogen pollutants in urine wastewater. The Ir-SnO2 anode outperformed counterparts such as IrO2, SnO2, and Sb-SnO2, demonstrating its superior electrochemical performance characterized by high current density, low charge transfer resistance, and substantial active surface area. It also achieved exceptional current efficiency of 91.7 % and energy efficiency of 7.79 mmol/Wh for RCS generation at 30 mA cm−2 in diluted 0.1 M chloride solution. Computational analysis based on density functional theory additionally supported experimental results, revealing that Ir doping to SnO2 enhances chlorine adsorption through electronic structure modification, significantly lowering the overpotential and improving electrocatalytic activity for chlorine evolution reactions. In the electrolysis of synthetic urine wastewater at 30 mA cm−2 for 5 h, the Ir-SnO2 anode demonstrated remarkable efficacy in degrading ammonia nitrogen (NH3-N), total nitrogen (TN), and chemical oxygen demand (COD) with efficiencies of 100 %, 97.8 %, and 89.1 %, respectively. These results were comparable to those achieved by IrO2 (dimensional stable anode, DSA) and exceeded the performance of the boron-doped diamond (BDD) anode. Moreover, Ir-SnO2 exhibited the lowest energy consumption compared to benchmark DSA and BDD anodes in the treatment of urine wastewater. In stability assessments, furthermore, the Ir-SnO2 electrode maintained stable anodic cell potential for 100 h of continuous electrolysis in a 0.1 M NaCl electrolyte at 30 mA cm−2 and remained functional over five cycles without any signs of deactivation. This study provides valuable insights into the development of a suitable anode for energy-efficient urine wastewater treatment.

Palladium nanocubes-mediated Fenton catalysis combined with chloride ion-amplified electro-driven catalysis for dye degradation

Electrochemical technology is frequently used to treat industrial dye wastewater. However, its degradation efficiency is restricted by pH, and the low current efficiency and high energy consumption limit its broader application. Based on this, we constructed an innovative electro-driven catalytic system by integrating nanotechnology with electric current. This system operates without pH constraints, has low energy consumption, and allows for the recycle and reuse of both electrodes and catalysts. Firstly, we synthesized palladium (Pd) cubes via a solvothermal method, and characterized their morphology, structural composition, and crystalline properties using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and other methods. The prepared Pd cubes possessed dual catalytic properties of electro-driven catalysis and Fenton catalysis, achieving a synergistic degradation effect under an electric field. Subsequently, the study explored how catalysts dosage, H2O2 concentration, pH and Cl− concentration affect the catalytic rate. The optimized system was able to degrade 99.17 % of MB within 1 h and was effective against various organic pollutants. After five cycles of reuse, the recovered catalysts maintained over 90 % degradation efficiency in decomposing MB. This process realizes efficient degradation with a low concentration of catalysts, offering a novel approach for nanotechnology in wastewater treatment under electro-driven conditions.

Additive-Assisted Hydrothermal Growth Enabling Defect Passivation and Void Remedy in Antimony Selenosulfide Solar Cells.

Antimony selenosulfide (Sb2(S,Se)3) has recently emerged as a promising light-absorbing material, attributed to its tunable photovoltaic properties, low toxicity, and robust environmental stability. However, despite these advantages, the current record efficiency for Sb2(S,Se)3 solar cells significantly lags behind their Shockley-Queisser limit, especially when compared to other well-established chalcogenide-based thin-film solar cells, such as CdTe and Cu(In,Ga)Se2. This underperformance primarily arises from the formation of unfavorable defects, predominately located at deep energy levels, which act as recombination centers, thereby limiting the potential for performance enhancement in Sb2(S,Se)3 solar cells. Specifically, deep-level defects, such as sulfur vacancy (VS), have a lower formation energy, leading to severe non-radiative recombination and compromising device performance. To address this challenge, thioacetamide (TA), a sulfur-containing additive is introduced, into the precursor solution for the hydrothermal deposition of Sb2(S,Se)3. This results indicate that the incorporation of TA helps in passivating deep-level defects such as sulfur vacancies and in suppressing the formation of large voids within the Sb2(S,Se)3 absorber. Consequently, Sb2(S,Se)3 solar cells, with reduced carrier recombination and improved film quality, achieved a power conversion efficiency of 9.04%, with notable improvements in open-circuit voltage and fill factor. This work provides deeper insights into the passivation of deep-level donor-like VS defects through the incorporation of a sulfur-containing additive, highlighting pathways to enhance the photovoltaic performance of Sb2(S,Se)3 solar cells.

Current Efficiency Comparison of Two Types of Rare Earth Electrolytic Cells: Flow Field Numerical Simulation Analysis and Experimental Investigation

Current Efficiency Comparison of Two Types of Rare Earth Electrolytic Cells: Flow Field Numerical Simulation Analysis and Experimental Investigation

Mathematical modeling of rare earth element separation in electrodialysis with adjacent anion exchange membranes and ethylenediaminetetraacetic acid as chelating agent

This research delves into the effective use of electrodialysis for the separation of rare earth elements (REEs), specifically separating dysprosium (Dy) from praseodymium (Pr) and neodymium (Nd). A robust mathematical model based on the extended Nernst-Planck equation is introduced, simulating the process within a configuration that includes two adjacent anion exchange membranes. The model integrates aspects such as feed equilibrium, ion exchange within the membrane, and overall ion flux. Validation of the model's predictability was conducted through Chi-squared tests and root mean square error (RMSE) calculations, affirming its capability to accurately predict ion concentrations across different compartments. The study examines essential parameters such as applied voltage, rinse solution concentration, and feed concentration, assessing their impacts on separation performance and energy efficiency. Results indicate that higher voltages above 8 V, while speeding up separation, detrimentally impact energy use. It also highlights a critical balance in rinse solution concentration; lower concentrations below 0.05 mol/L enhance energy efficiency but may undercut separation efficacy due to early depletion. A linear correlation between the necessary rinse concentration and feed concentration was established, with higher feed concentrations demonstrating reduced specific energy consumption, thus enhancing overall efficiency. However, challenges remain in current efficiency due to the independent migration of SO42− ions in this specific setup. The findings advocate exploring alternative configurations, like alternating cation and anion exchange membranes, to optimize both environmental and economic aspects of REE separation. This study provides valuable insights and recommendations for refining electrodialysis systems in REE processing, contributing to sustainable and cost-effective electrodialysis systems.

Current state and economic efficiency of ameliorative farming in the Republic of Tatarstan under conditions of climate aridity growth

The review article is devoted to the analysis and assessment of the impact of climate change on the efficiency of agricultural commodity production in the Republic of Tatarstan and ameliorative measures to overcome its negative impact on the performance of the agrarian sphere. Studies of agrometeorological data for 1900–2021 testify to the impending growth of climate aridity in the region. The analysis of modern conditions of meliorative industry development and its economic efficiency has shown that 1.5% of arable land area under irrigation allows to produce up to 18% of crop production in the republic, which certainly indicates a high degree of its efficiency. It has been established that the natural-climatic potential of the republic allows to bring the scale of irrigation reclamation up to four hundred thousand hectares, and to guarantee the need of the Republic of Tatarstan in foodstuffs of own production it is necessary to bring the volume of irrigated lands up to 150 thousand hectares, which allows to speak about the high export potential of the republic. High efficiency of land reclamation measures and existing measures of state support unfortunately do not provide its implementation in production activity of agrarian business entities due to the need for preliminary overly bureaucratized survey works, approvals for obtaining design and estimate documentation (DED). The scientific and substantiated measures of land reclamation industry development are proposed, contributing to the preservation and restoration of soil fertility, water resources, reducing the loss of agricultural land area, a multiple increase in the economic efficiency of agricultural production.

Rational Design of Coumarin-Based Hybridized Local and Charge-Transfer Blue Emitters for Solution-Processed Organic Light-Emitting Diodes.

Hybridized local and charge-transfer (HLCT) with the utilization of both singlet and triplet excitons through the "hot excitons" channel have great application potential in highly efficient blue organic light-emitting diodes (OLEDs). The proportion of charge-transfer (CT) and locally excited (LE) components in the relevant singlet and triplet states makes a big difference for the high-lying reverse intersystem crossing process. Herein, three novel donor (D)-acceptor (A) type HLCT materials, 7-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)-3-phenyl-1H-isochromen-1-one (pPh-7P), 7-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)-3-methyl-1H-isochromen-1-one (pPh-7M), and 6-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)-3-methyl-1H-isochromen-1-one (pPh-6M), were rationally designed and synthesized with diphenylamine derivative as donor and oxygen heterocyclic coumarin moiety as acceptors. The proportions of CT and LE components were fine controlled by changing the connection site of diphenylamine derivative at C6/C7-position and the substituent at C3-position of coumarin moiety. The HLCT characteristics of pPh-7P, pPh-7M, and pPh-6M were systematically demonstrated through photophysical properties and density functional theory calculations. The solution-processed doped OLEDs based on pPh-6M exhibited deep-blue electroluminescence with the maximum emission wavelength of 446 nm, maximum luminance of 8755 cd m-2, maximum current efficiency of 5.83 cd A-1, and maximum external quantum efficiency of 6.54 %. The results reveal that pPh-6M with dominant 1LE and 3CT components has better OLED performance.

Trans-electrode pressure of gas-diffusion electrodes significantly influencing the electrochemical hydrogen peroxide production

Hydrogen peroxide (H2O2) synthesis by electrochemical two-electron oxygen reduction has garnered increasing interest as a wide range of potential applications. Gas diffusion electrodes (GDEs) can effectively promote the H2O2 production efficiency by overcoming the oxygen mass transfer limitations but strongly influenced by the electrowetting process along the long-term operation. In this study, the effect of trans-electrode pressure (TEP) of GDE cathode on the electrowetting process was further elucidated. We controlled the TEP values of four types of GDEs: two Ni-based GDEs and two carbon cloth GDEs prepared by hot-pressing or brushing carbon black. SBA-15 was further used to regulate the microstructure of one Ni-based GDE. It was found that an optimal range of TEP occurred for all tested GDEs in terms of the max. concentration, the yield efficiency, the energy consumption, and the stability because TEP may change the triple-phase interface and influence the anti-electrowetting effect. The porosity of hot-pressed Ni GDE can maintain the TEP window and thus enhance the production of H2O2, likely via creating oxygen-containing functional groups and a bimodal pore structure on the electrode, revealed with several characterization techniques including SEM, CA, XPS, Raman spectra, CV and EIS. The porous Ni GDE presented an efficient and stable production of H2O2 for 10 cycles: yielding H2O2 at 4393.2–4602.2 mmol m−2 h−1 with current efficiencies of 94.2–98.7%. The best accumulated H2O2 concentration can reach up to 3.58 ωt% H2O2 at 10 h. The results provide an important reference for the industrial scaleup of electro-production of H2O2 with GDEs.

Visualizing Carrier Diffusion in Cs‐Doping FAPbI3 Perovskite Thin Films Using Transient Absorption Microscopy

AbstractThe determination of the semiconducting materials performance heavily relies on the diffusion coefficient and length of the carrier. Recently, significant progress is made in enhancing solar cell efficiency through improved carrier diffusion in perovskite thin films. However, the spatial‐temporal mechanisms underlying carrier transport remain unclear. Recent advancements in utilizing transient absorption microscopy (TAM) offer promising opportunities to directly visualize the carrier transport dynamics within perovskite films. Here, the wide‐field imaging TAM combined with X‐ray diffraction and scanning electron microscopy is employed to investigate the spatial‐temporal carrier transport dynamics in FA1−xCsxPbI3 perovskites with varying Cs doping ratios. The experimental results indicate that the diffusion constant remains consistent regardless of the excitation power. Moreover, a decrease in the Cs doping ratio leads to an increase in the diffusion length within FA1−xCsxPbI3 perovskites. The measurements reveal a highest diffusion coefficient of up to 0.085 cm2 s−1 and a maximum diffusion length of ≈1.4 µm in FA0.97Cs0.03PbI3. Comparative analysis of short‐circuit current density, open‐circuit voltage, fill factor, and power conversion efficiency demonstrates that FA0.97Cs0.03PbI3 exhibits superior device efficiency. The TAM visualizes spatial/ temporal carrier diffusion dynamics, showing a significant correlation with device efficiency and thus providing valuable insights for further enhancing device performance.

Elimination of nickel and chromium(VI) ions from industerial wastewater by electrodialysis/characteristics/impact of parameters

<p>Healthy water is a concern for the world due to rapid population growth and technological advancement. The entry of heavy metals into water as a result of various activities causes water pollution that has persistent effects. In this study, a specially designed electrodialysis cell was used to remove chromium (VI) and nickel ions from wastewater. The chambers were partitioned by Ionac MC 3470 cation exchange and Ionac MA 3475 anion exchange membranes. The cathode and anode were made of carbon fiber and stainless steel, respectively. The effects of voltage, initial pH, time, Na2SO4 concentration, feed flow rate and metal ion concentration on metal removal efficiency, energy consumption, current efficiency, current density and flux were investigated. Optimum values for 98.5% removal of 80 mg/L Cr(VI) ion in 90 min voltage 30 V, pH=3, addition of Na2SO4 0.5 g and feed flow rate 52. 8 ml/min, as observed. At the end of this period, concentration 1 mg/L, energy consumption 40 W/L, flow efficiency 30% and flux 12 x 10.-5 mol/m2s were calculated. Optimum values of 25 V, pH=3, addition of Na2SO4 0.2 g and Qf = 42.6 mL/min were observed for 94.3% removal of 50 mg/L Ni2+ ions in 90 min. At the end of this period, the nickel ion concentration was 4 mg/L, the energy consumption was 34 Wh/L, the flow efficiency was 96.51%, and the flux was calculated as 40×10-5 mol/m2s. This study shows that the electrodialysis method can be effectively used to elimonation chromium (VI) and nickel (II) ions from dilute wastewaters.</p>