Improved Conversion Efficiency Research Articles

Nickel-doped CNTs composite as cathode by sulfur vapor deposition for high-performance all-solid-state lithium‑sulfur batteries

Shuttle effect of polysulfide in the cathode and the safety issues arising from dendrite formation at Li metal anode are the main challenges of traditional liquid lithium‑sulfur batteries. In order to solve the shuttle effect and prevent short circuit, the all-solid-state lithium‑sulfur battery (ASSLSB) is proposed. However, the huge volume expansion of sulfur and the improvement of sulfur conversion efficiency during charge and discharge, which could lead to the limitation of electrochemical performance. Herein, a homogeneous Ni-doped carbon-nanotubes (H-Ni-SVD@CNT) composite cathode of ASSLSB is prepared by sulfur vapor deposition to confine sulfur and promote the conversion of sulfur and Li2S. In this work, SVD-5-S@CNT composite cathode demonstrates high reversible discharge capacity of 1001.1 mAh g−1 after 127 cycles and capacity retention rate of 78.6 % at the rate of 0.1C and 60 °C. Moreover, H-Ni-SVD@CNT composite cathode exhibits superior electrochemical performance, displaying the discharge specific capacity of 1519.3 mAh g−1 at 0.1C and 60 °C. Meanwhile, the discharge specific capacity of H-Ni-SVD@CNT composite cathode is 1060.9 mAh g−1 at room temperature. The synergistic effect of physical confinement and chemical catalysis improves the electrochemical performance of the all-solid-state lithium‑sulfur battery. This work proposes a new strategy for the cathode structure design of the all-solid-state lithium‑sulfur battery.

Molecular Design and High‐Throughput Virtual Screening of Electron Donor and Non‐fullerene Acceptors for Organic Solar Cells

The complicated trilateral relationships among molecular structures, properties, and photovoltaic performances of electron donor and acceptor materials hinder the rapid improvement of power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, the database of 310 donor and non‐fullerene acceptor pairs is constructed and 39 molecular structure descriptors are selected. Four kinds of machine learning (ML) algorithms random forest (RF), extra trees regression, gradient boosting regression trees, and adaptive boosting are applied to predict photovoltaic parameters. The coefficient of determination, Pearson correlation coefficient, mean absolute error, and root mean square error are adopted to evaluate ML performance. The results show that the RF model exhibits the best prediction accuracy. The Gini important analysis suggests the fused ring and aromatic heterocycles are critical fragments in determining PCE. The molecular unit sets are constructed by cutting each donor and acceptor molecules in database. The 31 752 D‐π‐A‐π type donor molecules and 5 455 164 A‐π‐D‐π‐A type acceptor molecules are designed by recombination of molecular units, and 173 212 367 328 donor–acceptor pairs are generated by combining the newly designed donor and acceptor molecules. Based on the predicted PCE using the trained RF model, 42 donor–acceptor pairs exhibit the predicted PCE > 16%, in which the highest PCE is 16.24%.

A poly(L-lactic Acid)-based flexible piezoelectric energy harvester with micro-zigzag structures

Piezoelectric energy harvester (PEH) holds great potential for flexible electronics and wearable devices. However, the power conversion efficiency of flexible PEH (fPEH) has often been a limiting factor, especially under variable excitation. Herein, we propose a practical solution: a poly(L-lactic acid)-based fPEH with 3D-printed micro-zigzag structures. This design not only broadens the operational bandwidth and enhances low-frequency response but also offers a tangible improvement in the power conversion efficiency of fPEH. The micro-zigzag structure was designed and fabricated using a digital light processing 3D printing technique with acrylates, a method that is readily accessible to researchers and engineers in the field. Mechanical properties of the 3D-printed acrylic elastomers with different compositions were investigated to obtain the material parameters, and then fPEH with the sandwich structure was fabricated via sputtering and packaging. Subsequently, numerical simulation was conducted on the micro-zigzag structures to determine the structure sizes and oscillation frequencies of fPEH. Finally, four micro-zigzag structures with 3-, 4-, 5- and 6 mm lengths were tested to obtain oscillation frequencies of 51, 37, 22, and 21 Hz consistent with the simulation. The output voltages of fPEH are 11–30 mV with the load ranges of 60–100 MΩ. Stability evaluation showed that the fPEH can work under low frequency (<100 Hz) and broadband conditions. The micro-zigzag structure provided new insights for the design of fPEH, paving the way for more efficient and practical energy harvesting solutions in the future.

Biomaterial Improves the Stability of Perovskite Solar Cells by Passivating Defects and Inhibiting Ion Migration.

With the rapid improvement of power conversion efficiency (PCE), perovskite solar cells (PSCs) have broad application prospects and their industrialization will be the next step. Nevertheless, the performance and long-term stability of the devices are limited by the defect-induced nonradiative recombination centers and ions' migration inside the perovskite films. Here, usnic acid (UA), an easy-to-obtain and efficient natural biomaterial with a hydroxyl functional group (-OH) and four carbonyl groups (-C═O) was added to MAPbI3 perovskite precursor to regulate the crystallization process by slowing the crystallization rate, thereby expanding the crystal size and preparing perovskite films with low defect density. In addition, UA anchors the uncoordinated Pb2+ and suppresses the migration of I-ions, which enhances the stability of the perovskite film. Consequently, an impressive PCE exceeding 20% was achieved for inverted structure MAPbI3-based PSCs. More impressively, the optimized PSCs maintained 78% of the initial PCE under air with high humidity (RH ≈ 65%, 25-30 °C) for 1000 h. UA can be extracted from the plant, usnea, making it inexpensive and easy to obtain. Our work demonstrates the application of the plant material in PSCs and their industrialization, which is significant nowadays.

Porous Prussian blue nanolayers formed in situ on Fe-MOFs-modified electrode surfaces by electrochemically triggered dual-templating effect for ultrasensitive detection of lead ions and Staphylococcus aureus

In this study, introducing Fe-MOFs as reactants to the electrode surface creates a novel mode for modulating interface performance that can lead to rapid enrichment of reactants in the proximity of electrodes by electrochemical-induced confinement effect. A facile, controllable, and room temperature electrochemical approach utilizes Fe-MOFs as nanotemplates to produce porous Prussian blue (PB) nanolayers on the electrode surfaces. Unlike conventional chemical conversion that needs a supply of exogenous acid regents, the electrochemical method creates a solid acidic condition in the oxygen evolution reaction cycle to release Fe3+ from the Fe-MOFs, improving conversion efficiency and electrochemical activity of PB. Furthermore, small oxygen bubbles generated by splitting H2O near the electrodes are also good templates, promoting the formation of porous structures that can increase effective surface area and mass-transfer efficiency. As a conceptional application, using Fe-MOFs as self-sacrificial tags, an ultrasensitive electrochemical platform with triple amplification is developed to detect Pb2+ and S. aureus based on DNAzyme-CHA cascade reaction. The designed platform shows low detection limits of 8.5 fM and 1 CFU/mL for Pb2+ and S. aureus, respectively. Moreover, the platform has high selectivity, stability and reproducibility, and also shows satisfactory recovery rates when validated using actual samples.

Scrutinizing transport phenomena and recombination mechanisms in thin film Sb2S3 solar cells

The Schockley–Quisser (SQ) limit of 28.64% is distant from the Sb2S3 solar cells’ record power conversion efficiency (PCE), which is 8.00%. Such poor efficiency is mostly owing to substantial interface-induced recombination losses caused by defects at the interfaces and misaligned energy levels. The endeavor of this study is to investigate an efficient Sb2S3 solar cell structure via accurate analytical modeling. The proposed model considers different recombination mechanisms such as non-radiative recombination, Sb2S3/CdS interface recombination, Auger, SRH, tunneling-enhanced recombination, and their combined impact on solar cell performance. This model is verified against experimental work (Glass/ITO/CdS/Sb2S3/Au) where a good coincidence is achieved. Several parameters effects such as thickness, doping, electronic affinity, and bandgap are scrutinized. The effect of both bulk traps located in CdS and Sb2S3 on the electrical outputs of the solar cell is analyzed thoroughly. Besides, a deep insight into the effect of interfacial traps on solar cell figures of merits is gained through shedding light into their relation with carriers’ minority lifetime, diffusion length, and surface recombination velocity. Our research findings illuminate that the primary contributors to Sb2S3 degradation are interfacial traps and series resistance. Furthermore, achieving optimal band alignment by fine-tuning the electron affinity of CdS to create a Spike-like conformation is crucial for enhancing the immunity of the device versus the interfacial traps. In our study, the optimized solar cell configuration (Glass/ITO/CdS/Sb2S3/Au) demonstrates remarkable performance, including a high short-circuit current (JSC) of 47.9 mA/cm2, an open-circuit voltage (VOC) of 1.16 V, a fill factor (FF) of 54%, and a notable improvement in conversion efficiency by approximately 30% compared to conventional solar cells. Beyond its superior performance, the optimized Sb2S3 solar cell also exhibits enhanced reliability in mitigating interfacial traps at the CdS/Sb2S3 junction. This improved reliability can be attributed to our precise control of band alignment and the fine-tuning of influencing parameters.

The differences between the hydrogenation by means of photon-injection and electron-injection for N-type tunnel oxide passivated contacts solar cells

Tunnel Oxide Passivated Contact (TOPCon) solar cells have received widespread attention in recent years, especially in improving conversion efficiency. This paper investigated the impact of hydrogenation technology using photon-injection (HPI) and electron-injection (HEI) processes on TOPCon solar cells, highlighting the higher improvement effect and broader application scope of HPI compared to HEI. In TOPCon cells, several methods are available to prepare the tunneling oxide layer, such as plasma oxidation (PO) and indirect thermal oxidation (TO). The research results indicated that significant improvement differences could be observed when utilizing the HEI treatment for TOPCon solar cells prepared by PO and TO methods, with values of 0.133%abs. and −0.039%abs., respectively. Meanwhile, HPI treatment induced a more significant efficiency improvement for these two types of cells, and the increase in efficiency is 0.247%abs. and 0.244%abs., respectively. The experimental results demonstrated that the passivation effect for TOPCon solar cells prepared by PO and TO methods remained almost the same under the HPI treatment, and the improvement effect is less dependent on the tunnel oxidation technique used. Thus, the different passivation effects between HPI and HEI were further investigated, and the reason for the difference was attributed to the charge states and concentrations of hydrogen and non-equilibrium carriers during the hydrogenation. The results provided an improved scheme for enhancing the efficiency of TOPCon solar cells, shedding light on the role of HPI and HEI in the passivation process. This work brings further insights to TOPCon solar cells.

Improving the Efficiency and Stability of Perovskite Solar Cells by Refining the Perovskite-Electron Transport Layer Interface and Shielding the Absorber from UV Effects.

This study aims to enhance the performance of perovskite solar cells (PSCs) by optimizing the interface between the perovskite and electron transport layers (ETLs). Additionally, we plan to protect the absorber layer from ultraviolet (UV) degradation using a ternary oxide system comprising SnO2, strontium stannate (SrSnO3), and strontium oxide (SrO). In this structure, the SnO2 layer functions as an electron transport layer, SrSnO3 acts as a layer for UV filtration, and SrO is employed to passivate the interface. SrSnO3 is characterized by its chemical stability, electrical conductivity, extensive wide band gap energy, and efficient absorption of UV radiation, all of which significantly enhance the photostability of PSCs against UV radiation. Furthermore, incorporating SrSnO3 into the ETL improves its electronic properties, potentially raising the energy level and improving alignment, thereby enhancing the electron transfer from the perovskite layer to the external circuit. Integrating SrO at the interface between the ETL and perovskite layer reduces interface defects, thereby reducing charge recombination and improving electron transfer. This improvement results in higher solar cell efficiency, reduced hysteresis, and extended device longevity. The benefits of this method are evident in the observed improvements: a noticeable increase in open-circuit voltage (Voc) from 1.12 to 1.16 V, an enhancement in the fill factor from 79.4 to 82.66%, a rise in the short-circuit current density (Jsc) from 24.5 to 24.9 mA/cm2 and notably, a marked improvement in the power conversion efficiency (PCE) of PSCs, from 21.79 to 24.06%. Notably, the treated PSCs showed only a slight decline in PCE, reducing from 24.15 to 22.50% over nearly 2000 h. In contrast, untreated SnO2 perovskite devices experienced a greater decline, with efficiency decreasing from 21.79 to 17.83% in just 580 h.

High‐Performance Inverted Perovskite Solar Cells by Dual Interfaces Modification with Identical Organic Salt

AbstractThe improvement of power conversion efficiency (PCE) and stability of perovskite solar cells (PSC) relies on the enhanced quality of perovskite layer and the modification of its adjacent interfaces. For this purpose, a multifunctional organic passivation molecule 1‐(4‐Fluorophenyl) biguanide hydrochloride (F‐BHCl) is introduced to the top and bottom interfaces of the perovskite layer. The PCE of PSC after the modification of double interfaces with F‐BHCl is significantly increased from 22.41% (unmodified) to 25.14%, and the storage, thermal, and operation stability is also improved. The comprehensive theoretical and experimental studies verify that due to its versatile functional groups and adaptation, F‐BHCl can significantly improve the quality of perovskite film, fully passivate several kinds of common defects, smoothen the top surfaces of perovskite film, and construct “molecular bridges” with carrier transporters on both the top and bottom surfaces, leading to significantly reduced non‐recombination and carrier transport losses. As a result, a significant increase is achieved in the open circuit voltage and fill factor as well as the whole performance of the device.

Study on Rock Interface Stability in the Heat Exchange Channel of the Horizontal Section of U-Shaped Wells in Hot Dry Rock

Enhanced Geothermal Systems (EGS) represent a promising direction for sustainable energy development, yet their efficiency and feasibility often suffer due to suboptimal heat extraction methods and interface instability in U-shaped wells. This study introduces an innovative volume encapsulation technology that aims to address these challenges. The proposed technology employs a combination of hydraulic fracturing and acidification to prepare the rock interface, followed by encapsulation using high-temperature liquid metal. Low-melting-point alloys are utilized as a heat exchange medium between the horizontal sections of the wells. This study meticulously analyzes the impact of formation stress, thermal shock stress, and liquid metal properties on rock interface stability. Advanced simulation tools and experimental setups were used to test the encapsulation process under various conditions. The application of liquid metal encapsulation demonstrated significant improvements in energy conversion efficiency and rock interface stability. In conditions simulating a dry and hot rock reservoir at depths up to 3000 m and temperature gradients reaching 2200 °C/m, the adjusted depth of horizontal sections and increased pumping pressure contributed to maintaining interface stability. The established failure criteria provide a robust theoretical foundation for the encapsulation process. Volume encapsulation technology using liquid metal not only enhances the operational efficiency of EGS but also stabilizes the rock interface, thereby increasing the feasibility of continuous geothermal energy extraction. This study offers valuable theoretical insights and practical guidance for future research and applications in geothermal energy technologies, creating new pathways for the efficient exploitation of geothermal resources.

Multifunctional Hydroxylamine‐O‐Sulfonic Acid as Additives for Highly Efficient and Stable Perovskite Solar Cells

Despite the rapid development of perovskite solar cells (PSCs), defects in the devices continue to impede further improvements in power conversion efficiency and operational stability. In this work, the use of hydroxylamine‐O‐sulfonic acid as a bifunctional molecule to enhance the performance of PSCs is described. Strong coordination exists between the sulfonic acid group and uncoordinated Pb2+ of perovskite, while the NH bond on amino group interacts with uncoordinated I−. Thus, due to the synergistic contribution of sulfonic acid group and amino groups, the high‐quality perovskite film with good crystallinity and low defect density is achieved. As a result, the optimal devices exhibit an enhanced efficiency of 23.33%, which is much higher than that of the control device (21.53%). Notably, the optimized target device exhibits excellent long‐term operational stability, retaining over 90% of its initial efficiency after 480 h at 65 °C, over 93% after a continuous illumination test for 650 h, and over 96% after nearly 1400 h of air storage. In contrast, the control device demonstrates poorer stability. In these results, it is suggested that selecting a dual‐functional additive is a promising approach to enhance efficiency and maintain stability in PSCs.

Tailoring the alkalinity of SnO2 colloidal suspension for high‐performance and stable perovskite solar cells

The commercial tin oxide (SnO2) colloidal suspension is widely utilized as an electron transport layer (ETL) in high‐performance perovskite solar cells (PSCs) due to its favorable material properties and potential for large‐scale production. However, despite significant efforts have been proposed to address bulk transport and interface recombination issues through the introduction of additives or modifiers, the efficiency of PSCs based on commercial SnO2 nanoparticles remains limited to around 25%. In this study, we highlight the crucial role of the physicochemical characteristics of the SnO2 colloidal suspension in shaping the morphology, electrical properties and optical properties of the SnO2 ETL. By controlling the pH value of the SnO2 solution with weak acids such as carbonic acid, we successfully induced the reassembly of metal oxide nanoparticles into smaller sizes with more homogeneous dispersion and dense interconnections. Consequently, the resulting SnO2 ETL exhibited enhanced crystallinity, high conductivity, low surface defects, and high optical transmittance. As a result, we achieved a significant improvement in the power conversion efficiency of the target PSCs, increasing it from 23.10% to 24.70%. This improvement was attributed to higher voltage, photocurrent, and fill factor compared to the relevant control samples. We observed a similar device improvement using phosphoric acid, indicating that our approach represents a universal technique to further enhance the quality of SnO2 ETL for large‐area, high‐efficiency, and stable PSCs.This article is protected by copyright. All rights reserved.

Performance analysis of modified residential PV system configuration under mismatch conditions

Partial shading is a prevalent phenomenon with a substantial impact on PV system performance. Various techniques, such as maximum power tracking (MPPT), PV module interconnection, and power electronics-based schemes, have been employed to address these challenges at both the module level and the submodule level. Existing methods face limitations related to the cost of hardware and the complexity of control systems. These limitations hinder the widespread application of current solutions. Also, Module-level techniques though simple and economical provide limited granularity. The choice between these techniques involves a trade-off between complexity, cost, adaptability, and the specific characteristics of the PV system and its operating environment.This paper presents a new hybrid submodule-level partial shading mitigation scheme based on TCT interconnection and differential power processing. The proposed system, emphasizing its role in enhancing overall PV system performance offers a cost-effective, and easy-to-control solution. To compare and validate the performance of proposed hybrid architecture, a practically installed single-phase grid tied central inverter 3 kW residential PV system is considered. This practical PV system is modified to hybrid architecture and the performance parameters such as power generation, mismatch power loss, fill factor, power conversion efficiency and power improvement calculated for different operating conditions. The results show that the modified conventional PV system mitigate the mismatch issue effectively and improves the output performance for any operating condition

Enhanced Electron Transport and Mitigated Voltage Loss in Perovskite Photovoltaics Using Sb2O5@SnO2 Composite Electron Transport Layer.

The efficacy of electron transport layers (ETLs) is pivotal for optimizing the device performance of perovskite photovoltaic applications. However, colloidal dispersions of SnO2 are prone to aggregation and possess structural defects, such as terminal-hydroxyls (OHT) and oxygen vacancies (VOs), which can degrade the quality of ETLs, impede charge extraction and transport, and affect the nucleation and growth processes of the perovskite layer. In this study, the Sb(OH)4 - ions hydrolyzed from SbCl3 in colloidal dispersion can bind to defect sites and effectively stabilize the SnO2 nanocrystals are demonstrated. Upon oxidative annealing, a Sb2O5@SnO2 composite film is formed, in which the Sb2O5 not only mitigates the aforementioned defects but also broadens the energy range of unoccupied states through its dispersed conduction band. The increased electron affinity (EA) facilitates more efficient capture of photoexcited electrons from the perovskite layer, thus augmenting electron extraction and minimizing electron-hole recombination. As a result, a significant improvement in power conversion efficiency (PCE) from 22.60% to 24.54% is achieved, with an open circuit voltage (VOC) of up to 1.195V, along with excellent stability of unsealed devices under various conditions. This study provides valuable insights for the understanding and design of ETLs in perovskite photovoltaic applications.

Optimal Rotor Design and Analysis of Energy-Efficient Brushless DC Motor-Driven Centrifugal Monoset Pump for Agriculture Applications

The agricultural sector emphasizes sustainable development and energy efficiency, particularly in optimizing water pumping systems for irrigation. Brushless DC (BLDC) motors are the preferred prime mover over induction motors due to their high efficiency in such applications. This article details the rotor design and analysis of an energy-efficient BLDC motor with specifications of 1 hp, 3000 rpm, and 48 V, specifically tailored for a centrifugal monoset pump for irrigation. The focus lies in achieving optimal energy efficiency through grey wolf optimization (GWO) algorithm in the rotor design to determine optimal dimensions of the Neodymium Iron Boron (NdFeB) magnet as well as its grade. The finite element method analysis software, MagNet, is used to model and analyze the BLDC motor. The motor parameters, such as speed, torque, flux functions, temperature, and efficiency, are analyzed. For performance comparison, the same model with different magnet models is also analyzed. Validation via 3D finite element analysis highlights improvements in magnet flux linkage, stator tooth flux density, and rotor inertia with increased magnet thickness. Simulation results affirm the consistent performance of the designed BLDC motor, preferably when efficiency is increased. This efficiency and the constant speed lead to an improvement in the overall conversion efficiency of 7% within its operating range, affirming that the motor pump system is energy-efficient.

Optimizing thin-film silicon solar cells with nanostructured TiO2 and a silver back reflector for enhanced energy conversion efficiency

This paper investigates the improvement of energy conversion efficiency in thin-film silicon solar cells by employing periodic nanostructures of TiO2 on the silicon active layer and a back reflector featuring periodic nanostructures of silver. The objective is to increase the optical path length, enhance absorption probability for longer wavelengths, and subsequently improve solar cell performance. Three silicon-based solar cell configurations are proposed and simulated using the finite difference time domain (FDTD) method to assess their performance. Electrical characteristics are obtained through the drift-diffusion method. The resulting short-circuit current density increased from 40.93 to 65.28 to 95.373mA/cm2 for the three cells, leading to significant improvements in conversion efficiency with observed values of 20.39%, 33.26%, and 47.28%, respectively, in the optimized structures. Furthermore, we compare the simulation results of the three structures with those of a reference structure and several structures previously proposed in the literature.

Modulating Secondary Growth of Perovskite Grains through Residual Solvent Evaporation

Modulating Secondary Growth of Perovskite Grains through Residual Solvent Evaporation

Dual Defect Passivation at the Buried Interface for Printable Mesoscopic Perovskite Solar Cells with Reduced Open-Circuit Voltage Loss.

Numerous defects exist at the buried interface between the perovskite and adjacent electron transport layers in perovskite solar cells, resulting in severe non-radiative recombination and excessive open-circuit voltage (VOC) loss. Herein, a dual defect passivation strategy utilizing guanidine sulfate (GUA2SO4) as an interface modifier is first reported. On the one hand, the SO4 2- preferentially interacts with Pb-related defects, generating water-insoluble lead oxysalts complexes. Additionally, GUA+ diffuses into the perovskite and induces the formation of low-dimensional perovskite. These reactions effectively suppress trap states at the buried interface and perovskite boundaries in printable mesoscopic perovskite solar cells (p-MPSCs), thus increasing the carrier lifetime. Meanwhile, GUA2SO4 optimizes the interface energy band alignment, thus accelerating the charge extraction and transfer at the buried interface. This synergistic effect of trap passivation and interface energy band alignment modulation is strongly demonstrated by an increase in average VOC of 70mV and the power conversion efficiency improvement from 17.51% to 18.70%. This work provides a novel approach to efficiently improve the performance of p-MPSCs through dual-targeted defect passivation at the buried interface.

Dual-Coupled-Inductor-Based High-Step-Up Boost Converter with Active-Clamping and Zero-Voltage Switching

Many applications, such as photovoltaic systems, uninterruptible power supplies, and automobile headlamps, need a high step-up DC–DC converter without isolation. The conventional boost converter has the advantages of simple topology and easy control. However, it has some shortcomings, such as insufficient step-up voltage ratio and poor efficiency when operating at large duty-cycle conditions. One of the popular topologies used to overcome these problems is the coupled-inductor boost converter. It utilizes the turn ratio of the coupled inductor to realize a higher step-up voltage ratio. The drawback is that the leakage inductance of the coupled inductor causes a huge voltage spike when the power switches are turned off. Moreover, because coupled inductors are characterized by their large volume and high profile, a conventional coupled-inductor boost converter is unsuited for photovoltaic systems, such as the solar microinverter. This study proposes a novel high-step-up boost converter to solve these problems. This proposed converter uses dual coupled inductors instead of the conventional coupled-inductor boost converter. The secondary side of the coupled inductor is connected in series to increase the step-up voltage ratio. The proposed converter utilizes active clamping to achieve zero-voltage switching (ZVS) for suppressing voltage spike and improving conversion efficiency. In addition, low-profile designs can be fulfilled easily for solar microinverters. The proposed converter and its control method are introduced. The operation principle, circuit characteristics, and circuit analysis are presented. A prototype converter with 300 W output power 25–40 VDC input voltage and 200 VDC output voltage was tested. All functions, including high step-up voltage ratio, ZVS, and active clamping, were achieved, and the highest efficiency was around at 94.7%.

BNQDs and Fe2O3QDs co-doped in porous g-C3N4 for accelerating photogenerated electron migration and enhancing photo-Fenton catalysis efficiency

With the maturity of advanced oxidation processes, photo-Fenton synergistic catalytic technology, as one of them, has become an irreplaceable strategy in environmental treatment and other fields. However, this technology suffers from drawbacks such as facile recombination of electron-hole pairs (e-/h+), low conversion efficiency between Fe3+ and Fe2+, and limited active sites. To address these issues, this study constructs a photo-Fenton synergistic system based on porous g-C3N4 (FBNCN) modified with BNQDs and Fe2O3QDs. Among them, the porous g-C3N4 provides more active sites and larger quantum dot anchoring space for the catalytic reaction. The introduction of the BNQDs effectively traps the hole (h+), reduces e-/h+ recombination, facilitates the photo-generated electrons leap, and accelerates charge transfer, while the anchoring of Fe2O3QDs enables efficient the migration of active sites and charges. This results in improved conversion efficiency between Fe3+ and Fe2+, leading to enhanced generation of ·O2- and ·OH species that exhibit excellent visible-light-catalyzed oxidation ability. Moreover, remarkable degradation efficiency was achieved for antibiotic organic pollutants (tetracycline hydrochloride, chlortetracycline hydrochloride, norfloxacin, amoxicillin) per unit of time using this catalyst system, thus providing a new method for antibiotic organic pollutant degradation. In-situ XPS technique was used to analyze the movement direction of the photogenerated charges of the composite photocatalytic materials and reveal the degradation mechanism under the synergistic system.