查看更多>>摘要：The systematic advances in the power conversion efficiency(PCE)and stability of perovskite solar cells(PSCs)have been driven by the developments of perovskite materials,electron transport layer(ETL)materials,and interfacial passivation between the relevant layers.While zinc oxide(ZnO)is a promising ETL in thin film photovoltaics,it is still highly desirable to develop novel synthetic methods that allow both fine-tuning the versatility of ZnO nanomaterials and improving the ZnO/perovskite interface.Among various inorganic and organic additives,zwitterions have been effectively utilized to passivate the perovskite films.In this vein,we develop novel,well-characterized betaine-coated ZnO QDs and use them as an ETL in the planar n-i-p PSC architecture,combining the ZnO QDs-based ETL with the ZnO/perovskite interface passivation by a series of ammonium halides(NH4X,where X=F,Cl,Br).The champion device with the NH4F passivation achieves one of the highest performances reported for ZnO-based PSCs,exhibiting a maximum PCE of～22％with a high fill factor of 80.3％and competitive stability,retaining～78％of its initial PCE under 1 Sun illumination with maximum power tracking for 250 h.
查看更多>>摘要：Perovskite solar cells have emerged as a promising technology for renewable energy generation.However,the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and long-term stable photorechargeable systems remains a persistent challenge.Issues such as electrical mismatch and restricted integration levels contribute to elevated internal resistance,leading to suboptimal overall efficiency(ηoverall)within photorechargeable systems.Additionally,the compatibility of perovskite solar cells with electrolytes from energy storage devices poses another significant concern regarding their stability.To address these limitations,we demonstrate a highly integrated photorechargeable system that combines perovskite solar cells with a solid-state zinc-ion hybrid capacitor using a streamlined process.Our study employs a novel ultraviolet-cured ionogel electrolyte to prevent moisture-induced degradation of the perovskite layer in integrated photorechargeable system,enabling perovskite solar cells to achieve maximum power conversion efficiencies and facilitating the monolithic design of the system with minimal energy loss.By precisely matching voltages between the two modules and leveraging the superior energy storage efficiency,our integrated photorechargeable system achieves a remarkable ηoverall of 10.01％while maintaining excellent cycling stability.This innovative design and the comprehensive investigations of the dynamic photocharging process in monolithic systems,not only offer a reliable and enduring power source but also provide guidelines for future development of self-power off-grid electronics.
查看更多>>摘要：Anion exchange membrane fuel cell(AEMFC)technology is attracting intensive attention,due to its great potential by using non-precious-metal catalysts(NPMCs)in the cathode and cheap bipolar plate materials in alkaline media.However,in such case,the kinetics of hydrogen oxidation reaction(HOR)in the anode is two orders of magnitude sluggish than that of acidic electrolytes,which is recognized as the grand challenge in this field.Herein,we report the rationally designed Ni nanoparticles encapsulated by N-doped graphene layers(Ni@NG)using a facile pyrolysis strategy.Based on the density functional theory calculations and electrochemical performance analysis,it is witnessed that the rich Pyridinic-N within the graphene shell optimizes the binding energy of the intermediates,thus enabling the fundamentally enhanced activity for HOR with robust stability.As a proof of concept,the resultant Ni@NG sample as the anode with a low loading(1.8 mg cm-2)in AEMFCs delivers a high peak power density of 500 mW cm-2,outperforming all of those of NPMC-based analogs ever reported.
查看更多>>摘要：Symmetrical solid oxide cells(SSOCs)are very useful for energy generation and conversion.To fabricate the electrode of SSOC,it is very time-consuming to use the conventional approach.In this work,we design and develop a novel method,extreme heat treatment(EHT),to rapidly fabricate electrodes for SSOC.We show that by using the EHT method,the electrode can be fabricated in seconds(the fastest method to date),benefiting from enhanced reaction kinetics.The EHT-fabricated electrode presents a porous structure and good adhesion with the electrolyte.In contrast,tens of hours are needed to prepare the electrode by the conventional approach,and the prepared electrode exhibits a dense structure with a larger particle size due to the lengthy treatment.The EHT-fabricated electrode shows desirable electrochemical performance.Moreover,we show that the electrocatalytic activity of the perovskite electrode can be tuned by the vigorous approach of fast exsolution,deriving from the increased active sites for enhancing the electrochemical reactions.At 900 ℃,a promising peak power density of 966 mW cm-2 is reached.Our work exploits a new territory to fabricate and develop advanced electrodes for SSOCs in a rapid and high-throughput manner.
查看更多>>摘要：Organic perovskites are promising semiconductor materials for advanced photoelectric applications.Their fluorescence typically shows a negative temperature coefficient due to bandgap change and structural instability.In this study,a novel perovskite-based composite with positive sensitivity to temperature was designed and obtained based on its inverse temperature crystallization,demonstrating good flexibility and solution processability.The supercritical drying method was used to address the limitations of annealing drying in preparing high-performance perovskite.Optimizing the precursor composition proved to be an effective approach for achieving high fluorescence and structural integrity in the perovskite material.This perovskite-based composite exhibited a positive temperature sensitivity of 28.563％℃-1 for intensity change and excellent temperature cycling reversibility in the range of 25-40 ℃ in an ambient environment.This made it suitable for use as a smart window with rapid response.Furthermore,the perovskite composite was found to offer temperature-sensing photoluminescence and flexible processability due to its components of perovskite-based compounds and polyethylene oxide.The organic precursor solvent could be a promising candidate for use as ink to print or write on various substrates for optoelectronic devices responding to temperature.
查看更多>>摘要：In engineering practice,the output performance of contact separation TENGs(CS-TENGs)increases with the increase of tribo-pair area,which includes increasing the size of single layer CS-TENGs(SCS-TENGs)or the number of units(zigzag TENGs).However,such two strategies show significant differences in output power and power density.In this study,to seek a universal CS-TENG design solution,the output performance of a SCS-TENG and a zigzag TENG(Z-TENG)is systematically compared,including voltage,current,transferred charge,instantaneous power density,and charging power density.The relationship between contact area and output voltages is explored,and the output voltage equation is fitted.The experimental results reveal that SCS-TENGs yield better performance than Z-TENGs in terms of voltage,power,and power density under the same total contact area.Z-TENGs show energy loss during the transfer of mechanical energy,and such loss is aggravated by the increasing number of units.The instantaneous peak power of the SCS-TENG is up to 22 times that of the Z-TENG(45 cm2).Furthermore,the power density of capacitor charging of SCS-TENGs is 131％of that of Z-TENGs,which are relatively close.Z-TENG is a feasible alternative when the working space is limited.
查看更多>>摘要：Wearable triboelectric nanogenerators(TENGs)have attracted attention owing to their ability to harvest energy from the surrounding environment without maintenance.Herein,polyetherimide-Al2O3(PAl)and polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP,PH)nanofiber membranes were used as tribo-positive and tribo-negative materials,respectively.Phytic acid-doped polyaniline(PANI)/cotton fabric(PPCF)and ethylenediamine(EDA)-crosslinked PAl(EPAl)nanofiber membranes were used as triboelectrode and triboencapsulation materials,respectively.The result showed that when the PAl-PH-based TENG was shaped as a circle with a radius of 1 cm,under the pressure of 50 N,and the frequency of 0.5 Hz,the open-circuit voltage(Voc)and short-circuit current(Isc)reached the highest value of 66.6 V and-93.4 to 110.1 nA,respectively.Moreover,the PH-based TENG could be used as a fabric sensor to detect fabric composition and as a sensor-inductive switch for light bulbs or beeping warning devices.When the PAl-PH-based TENG was shaped as a 5 × 5 cm2 rectangle,a 33 pF capacitor could be charged to 15 V in 28 s.Interestingly,compared to PAl nanofiber membranes,EPAl nanofiber membranes exhibited good dyeing properties and excellent solvent resistance.The PPCF exhibited＜5％resistance change after washing,bending,and stretching.
查看更多>>摘要：Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity.Herein,the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(Ⅵ)for the first time.The ultrasonic(60 kHz,100 W)induces piezoelectric potential to generate a 0.57 eV A-1 electric field,which is added to the direction of CdS(010)as a driving force to efficiently separate photogenerated charges.The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation,and the relevant rate constant(0.042 min-1)is about 12 and 53.8 times than that of LED and ultrasonication.More importantly,93.74％of U(Ⅵ)could be removed from natural uranium mine wastewater.Therefore,this piezo-photocatalysis system that reduces U(Ⅵ)to easily separable(UO2)O2·2H2O(s)provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.
查看更多>>摘要：The rapid development of stretchable electronics made by circuits,microchips,and encapsulation elastomers has caused the production of a large amount of electronic waste(e-waste).The degradation of elastomers can highly minimize the negative effects of e-wastes.However,chemicals that included acid,alkali,and organics were repeatedly used during the recycling process,which were environmentally unfriendly.Here,a water-modulation-degradation-reconstruction(WDR)polyvinylpyrrolidone(PVP)-honey composite(PHC)polymer-gel was developed and could be regarded as encapsulation elastomers to realize a fully recyclable water-degradable stretchable(WS)electronics with multi-functions.The stretchability of the PHC polymer-gel could be modulated by the change of its water retention.The Chip-integrated liquid metal(LM)circuits encapsulated with the modulated PHC encapsulation elastomer could withstand a strain value of～3000％.Moreover,we developed a WS biomedical sensor composed of PHC encapsulation elastomer,LM circuits,and microchips,which could be fully recycled by biodegrading it in water to reconstruct a new one.As before,the reconstructed WS biomedical sensor could still simultaneously realize the combination of ultra-stretchability,recycling,self-healing,self-adhesive,and self-conformal abilities.The results revealed that this study exercises a profound influence on the rational design of multi-functional WS electronics.
查看更多>>摘要：Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications.State of the art in the field is currently a two-step process:a high-quality graphene layer synthesis on metal substrate through chemical vapor deposition(CVD)followed by delicate layer transfer onto device-relevant substrates.Here,we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual-metal smart Janus substrate for a diffusion-limiting graphene formation to directly synthesize large area,high quality,and layer-tunable graphene films on arbitrary substrates without the post-synthesis layer transfer process.Carbon(C)ion implantation was performed on Cu-Ni film deposited on a variety of device-relevant substrates.A well-controlled number of layers of graphene,primarily monolayer and bilayer,is precisely controlled by the equivalent fluence of the implanted C-atoms(1 monolayer～4 × 1015 C-atoms/cm2).Upon thermal annealing to promote Cu-Ni alloying,the pre-implanted C-atoms in the Ni layer are pushed toward the Ni/substrate interface by the top Cu layer due to the poor C-solubility in Cu.As a result,the expelled C-atoms precipitate into a graphene structure at the interface facilitated by the Cu-like alloy catalysis.After removing the alloyed Cu-like surface layer,the layer-tunable graphene on the desired substrate is directly realized.The layer-selectivity,high quality,and uniformity of the graphene films are not only confirmed with detailed characterizations using a suite of surface analysis techniques but more importantly are successfully demonstrated by the excellent properties and performance of several devices directly fabricated from these graphene films.Molecular dynamics(MD)simulations using the reactive force field(ReaxFF)were performed to elucidate the graphene formation mechanisms in this novel synthesis approach.With the wide use of ion implantation technology in the microelectronics industry,this novel graphene synthesis approach with precise layer-tunability and transfer-free processing has the promise to advance efficient graphene-device manufacturing and expedite their versatile applications in many fields.
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