Efficient Charge Research Articles

Evaluating boron removal from aqueous solutions using membrane capacitive deionization (MCDI): Efficacy and limitations

In the present study, the feasibility of employing activated carbon-based membrane capacitive deionization (MCDI) for boron removal was systematically evaluated under various conditions, including different applied voltages, pH levels, initial boron concentrations, and boron-to-chloride molar ratios. When the pH of the solution exceeds 9, borate ions with a negative charge become the predominant species, facilitating easier removal during the charging period of both capacitive deionization (CDI) and MCDI. As demonstrated, MCDI can achieve a relatively higher mean deionization capacity of 2.84±0.19 mg/g at 1.2 V and pH 11, associated with a corresponding high charge efficiency of 99% and low energy consumption of 0.04 kWh/m3. More specifically, the results revealed a significant improvement in boron removal performance with the incorporation of ion exchange membranes into CDI. Additionally, MCDI exhibited considerably higher selectivity of boron over chloride ions compared to CDI, attributed to the charge promotion effect. However, the selectivity coefficient of boron over chloride was still need to be improved, identified as the primary constraint of MCDI. With the same ionic charge, chloride with smaller hydrated radius compared to boron was preferentially electrosorbed, thereby suppressing the electrosorption of borate ions. These findings suggest potential future directions for the treatment of boron in practical applications such as seawater desalination and wastewater reclamation in the semiconductor industry.

RETRACTED: Research on the kinetics characteristics and in-cylinder combustion of opposed rotary piston engine for different power output modes

As a new type of internal combustion engine, opposed rotary piston (ORP) engine has the advantages of simple structure and high working frequency, and can achieve high power density. Consequently, it stands as an ideal power source for hybrid power systems and unmanned aerial vehicles. The ORP engine has different power output modes, corresponding to different piston rotation and volume evolutions of combustion chamber. However, the effect of power output modes on kinetics characteristics and in-cylinder combustion of ORP engines are still uncovered. In this paper, the kinematic model of an ORP engine is established for scenarios involving power output by different shafts (Shaft 1 and Shaft 3). Meanwhile, the piston rotation patterns and cylinder volume variations are investigated correspondingly. Further, three-dimensional numerical model of the ORP engine is established, enabling analysis of in-cylinder combustion characteristics, engine performance, as well as nitrogen oxides (NOx) emissions. The results indicate that the volume variations of all cylinders follow a consistent pattern under the power output by Shaft 3. A pair of opposed cylinders features longer durations of intake and expansion strokes, and shorter durations of compression and exhaust strokes, the other pair of combustion chambers is the opposite under the power output by Shaft 1. The engine demonstrates a charging efficiency of 95.36 %, with corresponding indicated thermal efficiency and indicated power output of 38.08 % and 40.9 kW, respectively. The two adjacent cylinders present significantly different operation processes in the case of the power output by Shaft 1, achieving charging efficiencies of 94.29 % and 89.11 %, respectively, with the indicated thermal efficiency of 34.49 % and 31.60 %. The corresponding minimum indicated specific fuel consumption under the two power output modes are 211.7 g/kW∙h and 243.7 g/kW∙h, respectively, accompanied by NOx emission factors of 25.3 g/kW∙h and 17.6 g/kW∙h. With the given range of ignition timing, a trade-off relationship exists between the engine performance and NOx emissions. The power density of the case of power output by Shaft 3 is superior to that of Shaft 1.

Low-temperature microwave-assisted synthesis of Bi2WO6/Bi2S3 heterojunction for photocatalytic reduction of Cr(VI) in industrial wastewater

Cr(VI) pollution has become a worldwide environmental issue due to its toxicity and non-biodegradability in wastewater. Herein, a Bi2S3/Bi2WO6 (BWS) Z-scheme heterojunction was successfully fabricated via a low-temperature in situ sulfurization process assisted by microwave irradiation and applied to the photocatalytic reduction of Cr(VI) in industrial electroplating wastewater. The effects of Bi2S3 loading, catalyst dosage, light source, and synthesis method on the catalytic performance of the heterojunctions were investigated. Remarkably, the optimized BWS-6 heterojunction achieved 100% Cr(VI) removal within 50 min under LED light irradiation and 30 min under sunlight irradiation, which greatly exceeded the pure Bi2S3 and Bi2WO6. In addition, BWS-6 exhibited high photostability, and it still sustained preferable photocatalytic Cr(VI) reduction activity under sunlight irradiation when the experiment was scaled up 20 times. The high photocatalytic activity of BWS photocatalysts can be ascribed to enlarged surface area, active centers, and intimate interfacial contact of Z-scheme heterojunction, which greatly improve visible-light harvesting, surface adsorption, and the transport efficiency of interfacial charge. Experimental and theoretical calculation results further evidenced a built-in electric field forming at the interface of the Z-scheme heterojunction and unveiled a possible photocatalytic reduction pathway. This work provides valuable information for large-scale applications in the removal of Cr(VI) from industrial wastewater by Z-scheme heterojunctions.

How multi-level porous carbon structure affects electrocatalytic properties?

For zinc-air batteries, it is crucial to develop bifunctional electrocatalysts that exhibit exceptional activity, high stability, and low cost. Based on this, three-dimensional carbon-based catalysts with multiple pore sizes were successfully prepared by using three different combinations of soluble salts as hard templates for controlling morphology and structure. These catalysts are denoted as 3D Co/NCBMS. Because of the synergistic effect of heteroatomic doping and a multi-level porous structure, 3D Co/NCBMS exhibits better catalytic properties for OER and ORR, comparable to IrO2 and Pt/C. The half-wave potential of the 3D Co/NCBMS catalyst was 0.82 V (vs RHE) in the ORR reaction and 1.54 V in the OER reaction. 3D Co/NCBMS samples exhibit excellent stability, maintaining a charge and discharge efficiency of approximately 54 % after stable cycling for 225 h. It also demonstrates high resistance to methanol poisoning, with the current remaining at around 95 % in alkaline electrolyte solutions when assembled into zinc-air batteries.

Enhanced localized therapeutic precision: A face-to-face folate-targeted Cu2+-mediated nanotherapy with thermosensitive sustained-release system

Safe and effective Cu2+ supplementation in local lesion is crucial for minimizing toxicity of DSF-based chemotherapy. Targeted delivery of Cu2+ appears more promising. Intraperitoneal chemotherapy for peritoneal carcinoma (PC) establishes “face-to-face” contact between targeted nanocarriers and tumor tissue. Herein, this study developed a biodegradable, injectable thermosensitive hydrogel that coencapsulating DSF submicroemulsion (DSF-SE) and folate-modified liposome loading glycyrrhizic acid-Cu (FCDL). FCDL acted as ‘beneficial horse’ to target the tumor-localized folate receptor, thus liberating Cu2+ in tumor nidus. The prepared FCDL and DSF-SE were found with uniform sizes (160.2 nm, 175.4 nm), low surface charge (−25.77 mV, −16.40 mV) and high encapsulation efficiency (97.93 %, 90.08 %). In vitro drug release profile of FCDL, DSF-SE and FCDL＆DSF-SE@G followed a sustained release pattern. And the release behavior of Cu2+ from FCDL was pH-related, i.e., Cu2+ was released faster under acidic condition. When FCDL and DSF-SE were loaded into an PLGA-PEG-PLGA-based hydrogel system, FCDL＆DSF-SE@G was formed to ensure separated delivery of Cu2+ and DSF in space but synchronized release over time. The rheology experiment showed a satisfactory gelling temperature of 32.7 °C. In vitro cytotoxicity study demonstrated that FCDL＆DSF-SE@G significantly lowered the IC50 of free Cu2+/DSF, Cu2+/DSF hydrogel and non-targeted analogue by almost 70 %, 65 % and 32 %, respectively. Accordingly, in tumor-bearing mice, FCDL＆DSF-SE@G augmented the tumor inhibition rates for the same formulations by 352 %, 145 % and 44 %, respectively. The main mechanism was attributed to higher uptake of FCDL and DSF-SE, resulting in increased Cu(DDTC)2 formation, ROS production and cell apoptosis. In conclusion, this targeted nanotherapy approach with dual-nanocarriers loaded hydrogel system, with its focus on face-to-face contact between nanocarriers and tumor tissues in the peritoneal cavity, holds significant promise for intraperitoneal chemotherapy in PC.

Pitch-based porous carbon via the solid–liquid synergistic oxidation of K2FeO4 for excellent electrocapacitive desalination

To address limited desalination capacity and insufficient charge efficiency for carbon materials in capacitive deionization (CDI), a solid–liquid synergistic oxidation strategy of potassium pertechnetate (VI) for pitch was proposed to construct porous carbon with a reasonable pore structure and high reactive surface. On the one hand, K2FeO4 is first utilized for the solid-phase oxidation (SPO) of pitch by a high-energy ball mill, introducing rich oxygen-containing groups such as ether bonds. Meanwhile, dehydro-condensation reactions occurred during SPO, resulting in the formation of the oxidized pitch with a high degree of condensation. Importantly, the pyrolysis yield of the oxidized pitch is as high as 46.9 % at 800 °C, almost twice that of the pristine pitch, meaning that the oxidized pitch with high polymer degree and rich C-O bridge bonds facilitates the carbon fixation and emission reduction during carbonization. On the other hand, the self-oxidation of K2FeO4 in aqueous solution forms bifunctional activators (KOH and Fe(OH)3) for the preparation of pitch-based porous carbon. Benefiting from the crosslinking structure of oxidized pitch and the multi-effective activation, the prepared porous carbon (H-CBPF) exhibits a robust layered stacking topology with a high surface area and oxygen content. Thereby, it can deliver an excellent salt adsorption capacity (SAC) of 22.1 mg g−1 with an average desalination rate of 1.89 mg g−1 min−1 and a high charge efficiency of 85 % at 1.2 V in 500 mg L-1 NaCl solution. This work opens up a green and economical route for the preparation of pitch-derived porous carbon for high-performance CDI.

Cell selective BCL-2 inhibition enabled by lipid nanoparticles alleviates lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a high mortality rate due to limited treatment options. Current therapies cannot effectively reverse the damage caused by IPF. Research suggests that promoting programmed cell death (apoptosis) in myofibroblasts, the key cells driving fibrosis, could be a promising strategy. However, inducing apoptosis in healthy cells like epithelial and endothelial cells can cause unwanted side effects. This project addresses this challenge by developing a targeted approach to induce apoptosis specifically in myofibroblasts. We designed liposomes (LPS) decorated with peptides that recognize VCAM-1, a protein highly expressed on myofibroblasts in fibrotic lungs. These VCAM1-targeted LPS encapsulate Venetoclax (VNT), a small molecule drug that inhibits BCL-2, an anti-apoptotic protein. By delivering VNT directly to myofibroblasts, we hypothesize that VCAM1-VNT-LPS can selectively induce apoptosis in these cells, leading to reduced fibrosis and improved lung function. We successfully characterized VCAM1-VNT-LPS for size, surface charge, and drug loading efficiency. Additionally, we evaluated their stability over three months at different temperatures. In vitro and in vivo studies using a bleomycin-induced mouse model of lung fibrosis demonstrated the therapeutic potential of VCAM1-VNT-LPS. These studies showed a reduction in fibrosis-associated proteins (collagen, α-SMA, VCAM1) and BCL-2, while simultaneously increasing apoptosis in myofibroblasts. These findings suggest that VCAM1-targeted delivery of BCL-2 inhibitors using liposomes presents a promising and potentially selective therapeutic approach for IPF.

Fullerene derivatives barrier layer for efficient and stable perovskite solar cells through interfacial modification and removal of superoxide radicals

Superoxide radicals(O2•–)-induced decomposition of perovskite, which seriously impairs the photovoltaic performance and stability of perovskite solar cells (PSCs). Both TiO2 and perovskite produce O2•– that accelerates the rate of catalytic degradation at the interface and inherently poor interfacial contact, exacerbating charge recombination and efficiency loss. Adding fullerene phenol derivative (C60HTB) to the perovskite/TiO2 interface absorbs O2•– and improves poor interfacial communication. The PSCs' power conversion efficiency (PCE) is improved from 20.54 % to 21.63 %. The target devices retained 91.20 %, 94.86 %, and 89.36 % of their initial power conversion efficiencies after 48 h of aging under full-spectrum illumination, 240 h of aging under ultraviolet illumination, and dark storage in air for 500 h, respectively. In this work, efficient and stable TiO2-based-PSCs were realized by scavenging O2•–, which opens a new way to enhance the stability of PSCs in light and O2 environments (light/oxygen).

Bile acid/fatty acid integrated nanoemulsomes for nonalcoholic fatty liver targeted lovastatin delivery: stability, in-vitro, ex-vivo, and in-vivo analyses

ABSTRACT Background Controlled and targeted drug delivery to treat nonalcoholic fatty liver disease (NAFLD) can benefit from additive attributes of natural formulation ingredients incorporated into the drug delivery vehicles. Methods Lovastatin (LVN) loaded, bile acid (BA) and fatty acid (FA) integrated nanoemulsomes (NES) were formulated by thin layer hydration technique for synergistic and targeted delivery of LVN to treat NAFLD. Organic phase NES was comprised of stearic acid with garlic (GL) and ginger (GR) oils, separately. Ursodeoxycholic acid and linoleic acid were individually incorporated as targeting moieties. Results Stability studies over 90 days showed average NES particle size, surface charge, polydispersity index, and entrapment efficiency values of 270 ± 27.4 nm, −23.8 ± 3.5 mV, 0.2 ± 0.04 and 81.36 ± 3.4%, respectively. Spherical NES were observed under a transmission electron microscope. In-vitro LVN release depicted non-fickian release mechanisms from GL and GR oils-based NES. Ex-vivo permeation of BA/FA integrated NES through isolated rat intestines showed greater flux than non-integrated ones. Conclusion Liver histopathology of experimental rats together with in-vivo lipid profiles and liver function tests illustrated that these NES possess the clinical potential to be promising drug carriers for NAFLD.

Enhanced EV Battery Monitoring Using IoT with Improved SEPIC - ZETA Converter and Modified Lion Optimization for Photovoltaic Systems

The rising popularity of electric vehicles (EVs) and the increasing emphasis on sustainable transportation have highlighted the importance of advanced monitoring systems. These systems play a crucial role in providing real-time information about battery parameters to ensure optimal performance and longevity. Moreover, the integration of renewable energy sources, specifically photovoltaic (PV) systems, with EV charging infrastructure presents an exciting prospect to enhance energy efficiency and minimize environmental harm. As a consequence the proposed work develops an Internet of Things (IoT) based PV fed EV charging system. The system incorporates an improved SEPIC-Zeta converter together with Modified Lion Optimization algorithm (LOA) assisted Proportional Integral (PI) controller for optimizing PV system for charging EV battery. IoT connectivity monitors parameter such as PV voltage, PV current, and State of Charge (SOC) of battery. Real-time monitoring of these parameters is achieved by leveraging sensors. The collected data is transmitted through IoT networks to a central monitoring system, enabling operators to track the performance of PV system and EV battery. This facilitates optimized energy generation, efficient battery charging and discharging, and overall system reliability. IoT-enabled monitoring system provides remote accessibility, data analytics, and the generation of alerts and notifications for timely actions. Experimental validation demonstrates that, the proposed concept enhances the monitoring capabilities, improves energy efficiency, and ensures reliable operation of EV charging infrastructure.

Engineering pH-sensitive dissolution of lipid-polymer nanoparticles by Eudragit integration impacts plasmid DNA (pDNA) transfection

Lipid-polymer nanoparticles offer a promising strategy for improving gene nanomedicines by combining the benefits of biocompatibility and stability associated with the individual systems. However, research to date has focused on poly-lactic-co-glycolic acid (PLGA) and resulted in inefficient transfection. In this study, biocompatible Eudragit constructs E100 and RS100 were formulated as lipid-polymer nanoparticles loaded with pDNA expressing red fluorescent protein (RFP) as a model therapeutic. Using a facile nanoprecipitation technique, a core–shell structure stabilised by lipid-polyethylene glycol (PEG) surfactant was produced and displayed resistance to ultracentrifugation. Both cationic polymers E100 (pH-sensitive dissolution at 5) and RS100 (pH-insensitive dissolution) produced 150–200 nm sized particles with a small positive surface charge (+3–5 mV) and high pDNA encapsulation efficiencies (EE) of 75–90%. The dissolution properties of the Eudragit polymers significantly impacted the biological performance in human embryonic kidney cells (HEK293T). Nanoparticles composed of polymer RS100 resulted in consistently high cell viability (80–100%), whereas polymer E100 demonstrated dose-dependent behaviour (20–90% cell viability). The low dissolution of polymer RS100 over the full pH range and the resulting nanoparticles failed to induce RFP expression in HEK293T cells. In contrast, polymer E100-constructed nanoparticles resulted in reproducible and gradually increasing RFP expression of 26–42% at 48–72 h. Intraperitoneal (IP) injection of the polymer E100-based nanoparticles in C57BL/6 mice resulted in targeted RFP expression in mouse testes with favourable biocompatibility one-week post-administration. These findings predicate Eudragit based lipid-polymer nanoparticles as a novel and effective carrier for nucleic acids, which could facilitate pre-clinical evaluation and translation of gene nanomedicines.

Formulation of silymarin surface modified vesicles: In vitro characterization to cell viability assessment

Silymarin (SLR) is a poorly water-soluble bioactive compound with a wide range of therapeutic activities. Nanosized silymarin vesicles (F1–F6) were prepared by the solvent evaporation rehydration method. The silymarin vesicles were evaluated for vesicle size, surface charge, entrapment efficiency, and drug release studies. The optimized SLR lipid vesicle (F3) was further modified with the addition of the cationic polymer chitosan. After that, the modified vesicle (F3C1) was assessed for permeation flux, antimicrobial activity, cell viability, and molecular docking studies. The silymarin vesicles showed nanometric size (<250 nm), low polydispersibility index (<0.05), negative surface charge, and high SLR entrapment (85–95 %). The drug release study result demonstrated a maximum drug release of 91.2 ± 2.8 %. After adding chitosan to the surface, there was a significant change in the size, polydispersibility index, surface charge (positive), and encapsulation efficiency. The drug release was found to be prolonged, and the permeation flux was also increased in comparison to free SLR. A comparative antimicrobial result was observed in comparison to the free SLR and standard drug. The cell viability assay also demonstrated a low IC50 value for F3C1 against the cell line.

LazyFrog: Advancing Security and Efficiency in Commercial Wireless Charging with Adaptive Frequency Hopping.

With the proliferation of electronic devices and electricity-based mobility solutions, the significance of wireless power transfer technology has increased substantially. However, ensuring secure and reliable power transmission to authorized users remains a significant challenge. Addressing this complex issue requires an integrated approach that balances efficiency, stability, and security considerations. While current efforts primarily focus on improving charging efficiency and user convenience, integrating robust security measures into wireless charging infrastructure is challenging due to its inherently open nature and susceptibility to external interference. Technical advancements are required to strengthen the security of the wireless charging infrastructure; however, these should be balanced with power loss management. This study tackles two core issues: the increasing hardware requirements for billing system authentication protocols and the interception of wireless charging signals by unauthorized users, leading to power theft and subsequent losses. To address these challenges, we propose a mechanism termed "LazyFrog". This mechanism dynamically adjusts the frequency hopping schedule, activating frequency changes only in response to detected threats during remote charging or upon identifying unauthorized access attempts. The proposed mechanism compares the expected power reception at the device with the actual power supplied by the charging station, enabling the detection of abnormal power losses. By minimizing unnecessary frequency changes and optimizing energy consumption, LazyFrog reduces hardware requirements. Moreover, we have implemented a relative distance estimation mechanism to facilitate efficient power transfer as wireless devices move within the charging environment. With these features, LazyFrog demonstrates a secure, flexible, and energy-efficient wireless charging system ready for practical application.

Electrochemical-Thermal-Mechanical Coupling Analysis of Lithium-Ion Batteries under Fast Charging

Thermal runaway and volume expansion caused by temperature rise under fast charging of lithium-ion batteries (LIBs) are the major reasons of battery explosion and cycle performance degradation. In this work, considering the radiation heat transfer on the battery surface, an electrochemical-thermal-mechanical coupling model of cylindrical LIBs under fast charging (state of charge (SOC) ≤80%) is developed in order to investigate the distributions of the temperature and stress. Then, choosing 18650 LIBs as the object, the charge efficiency, temperature, and stress distributions are compared between fast charging and galvanostatic operation under SOC≤80%, respectively. Finally, the influences of the thickness, particle radius, the maximum lithium-ion concentration of the cathode, and initial electrolyte concentration on the temperature, radial stress, and hoop stress of LIB during charge are explored, respectively. Numerical results show that fast charging improves 20.8% of the charge efficiency. Increasing the cathodic thickness and decreasing the cathodic maximum lithium-ion concentration or initial electrolyte concentration can reduce the temperature of LIB during the charge. The results of this work will provide some reference value for the design of LIBs under fast charging.

UAV-based solution for extending the lifetime of IoT devices: efficiency, design and sustainability

Internet of Things technology is named as a key ingredient in the evolution towards digitization of many applications and services. A deployment based on battery-powered remote Internet of Things (IoT) devices enables easy installation and operation, yet the autonomy of these devices poses a crucial challenge. A too short lifespan is undesirable from a functional, economical, and ecological point of view. This paper presents a unmanned aerial vehicle (UAV)-based approach to recharge remote Internet of Things (IoT) nodes. An in-depth study of the charging efficiency and optimization of key parameters, and measurements-based verification, is reported on. An actual corresponding design and implementation of the full UAV-based charging system and its proof-of-concept validation are presented. Finally, the sustainability of the proposed solution is discussed. The results presented in this paper hence confirm that the proposed UAV-based approach and design are functionally successful and efficient charging can be achieved, provided the constraints and challenges coming with the approach are adequately dealt with. Moreover, it comes with an overall reduction in ecological footprint for IoT applications relying on battery-powered nodes in need of medium energy and/or considerable lifetime expectation (5 years or more).

Contribution of regenerative suspension module to charge efficiency and range in hydrogen fuel cell electric vehicles

Energy and transport are the two largest contributors to carbon emissions. In recent years, the transport sector has made strides in reducing its carbon footprint by producing electric vehicles that emit zero carbon. This paper investigates the use of Fuel Cell Electric Vehicles (FCEVs) with a newly developed regenerative suspension module (RSM). The RSM uses an electromechanical mechanism to obtain regenerative electrical energy from the engine and is mounted to the passive suspension system. To determine the potential energy savings of the RSM module, a hydrogen fuel cell electric vehicle simulated under specific road geometries, speeds, and acceleration conditions. The simulation results indicate that the Regenerative Suspension Modules (RSM) mounted on each wheel of the FCEV generate 2.5 times more energy than the regenerative braking system. This result is evaluated as an increase in efficiency and range in electric vehicles.

Topology optimization of gyroid structure-based metal hydride reactor for high-performance hydrogen storage

Numerous engineering applications stand to gain substantial advantages by mitigating structural weight. While methods for optimizing continuous solids and discrete frame structures have long been available, the advent of additive manufacturing techniques has ushered in the potential for intricate geometries. In contrast, the hydrogen fuel sector confronts a pivotal challenge: the need to develop efficient hydrogen storage systems. Solid-state compounds like metal hydrides (MH) present a compelling solution among various hydrogen storage technologies thanks to their inherent safety attributes and superior hydrogen volumetric density. Nonetheless, the limitation of MH lies in its gravimetric density, impeding its application in mobility contexts. A transformative strategy addresses this limitation by seamlessly integrating the reactor tank into the vehicle's frame and chassis. This study introduces a pioneering concept—an optimally designed MH container incorporating a gyroid structure. Subsequently, this innovative design underwent rigorous analysis, employing finite element analysis (FEA) and computational fluid dynamics, assessing mechanical properties, heat transfer capabilities, and the efficiency of hydrogen charging into the MH within the structure. Using topology optimization of solid isotropic material with penalization method, a 17 % increase in the chamber volume and a concurrent reduction of the material by nearly 50 %. This profound transformation positively impacted the reactor's volumetric and gravimetric density. Despite a measurable reduction in strength, the optimized structure demonstrated resilience, successfully withstanding prescribed mechanical shear loads. Furthermore, the structure exhibited impressive rigidity, with displacement below 0.2 mm, rendering it suitable and highly competent for integration into assembly components like vehicle frames or chassis. Notably, the optimized structure exhibited a promising enhancement in hydrogen charging rate.

Enhancing Carrier Transport in 2D/3D Perovskite Heterostructures through Organic Cation Fluorination.

The interfacial 2D/3D perovskite heterostructures have attracted extensive attention due to their unique ability to combine the high stability of 2D perovskites with the remarkable efficiency of 3D perovskites. However, the carrier transport mechanism within the 2D/3D perovskite heterostructures remains unclear. In this study, the carrier transport dynamics in 2D/3D perovskite heterostructures through a variety of time-resolved spectroscopic measurements is systematically investigated. Time-resolved photoluminescence results reveal nanosecond hole transfer from the 3D to 2D perovskites, with enhanced efficiency through the introduction of fluorine atoms on the phenethylammonium (PEA) cation. Transient absorption measurements unveil the ultrafast picosecond electron and energy transfer from 2D to 3D perovskites. Furthermore, it is demonstrated that the positioning of fluorination on the PEA cations effectively regulates the efficiency of charge and energy transfer within the heterostructures. These insightful findings shed light on the underlying carrier transport mechanism and underscore the critical role of cation fluorination in optimizing carrier transport within 2D/3D perovskite heterostructure-based devices.

Design and investigation of small-scale long-distance RF energy harvesting system for wireless charging using CNN, LSTM, and reinforcement learning

Introduction: The energy supply challenge in wireless charging applications is currently a significant research problem. To address this issue, this study introduces a novel small-scale long-distance radio frequency (RF) energy harvesting system that utilizes a hybrid model incorporating CNN, LSTM, and reinforcement learning. This research aims to improve RF energy harvesting and wireless charging efficiency.Method: The methodology of this study involves data collection, data processing, model training and evaluation, and integration of reinforcement learning algorithms. Firstly, RF signal data at different distances are collected and rigorously processed to create training and testing datasets. Next, the CNN-LSTM model is trained using the prepared data, and model performance is enhanced by adjusting hyperparameters. During the evaluation phase, specialized test data is used to assess the accuracy of the model in predicting RF energy harvesting and wireless charging efficiency. Finally, reinforcement learning algorithms are integrated, and a reward function is defined to incentivize efficient wireless charging and maximize energy harvesting, allowing the system to dynamically adjust its strategy in real time.Results: Experimental validation demonstrates that the optimized CNN-LSTM model exhibits high accuracy in predicting RF energy harvesting and wireless charging efficiency. Through the integration of reinforcement learning algorithms, the system can dynamically adjust its strategy in real time, maximizing energy harvesting efficiency and charging effectiveness. These results indicate significant progress in long-distance RF energy harvesting and wireless charging with this system.Discussion: The results of this study validate the outstanding performance of the small-scale long-distance RF energy harvesting system. This system is not only applicable to current wireless charging applications but also demonstrates potential in other wireless charging domains. Particularly, it holds significant prospects in providing energy support for wearable devices, Internet of Things (IoT), and mobile devices.

A simply prepared amine oxide molecule as a low work function cathode modifier in organic photovoltaics for harvesting ambient light

Organic photovoltaics (OPV) that possibly convert ambient lights to electric energy are under the spotlight as a power supplier for portable, wearable, and Internet of Things devices. In order to enable the commercialization of ambient light harvesters, it is imperative to design and synthesize device components that offer cost-effectiveness, uniform deposition, and efficient charge extraction/collection. Here, we introduce a simple cathode interlayer (CIL) named EtNO for OPV-based ambient light harvesters. EtNO is designed with a chemical structure that does not require complicated conjugated units and is synthesized through a one-step procedure. EtNO CIL shows efficient reductions in the work function of electrodes, attributed to an interfacial dipole induced from an interaction between amine oxide group of EtNO and electrodes. Furthermore, EtNO forms a uniform layer through solution-processing without deteriorative effects on the surface of photoactive layer in OPVs. Therefore, the OPV with EtNO CIL exhibits an improved performance with an output power density of 79.2 μW cm–2 under light emitting diode illumination (1000 lx, 254 μW cm–2) compared to the device with conventional PDINO CIL (73.1 μW cm–2). Studies conducted on OPVs under halogen light illumination and on large-area devices further demonstrate the significant potential of EtNO as a CIL.