Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al)and its application for high-performance Zn-ion capacitor

It is of great scientific and economic value to recycle waste poly(ethylene terephthalate)(PET)into high-value PET-based metal organic frameworks(MOFs)and further convert it into porous carbon for green energy storage applications.In the present study,a facile and costeffective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53(Al)with a 100% conversation,then the MOFderived porous carbon was assembled into electrodes for high-performance supercapacitors.The results indicated that the as-synthesized carbon exhibited high SSA of 1712 m^(2)g^(-1)and unique accordion-like structure with hierarchical porosity.Benefit to these advantageous characters,the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g^(-1)at the current density of 0.5 A g^(-1)and good rate capability of 73.6% capacitance retention at 20 A g^(-1)in 6 mol L^(-1)KOH electrolyte.Furthermore,the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g^(-1)at 0.1 A g^(-1),excellent cycling stability of 92.2% capacitance retention after 10000 cycles and ultra-high energy density of 150.3 Wh kg^(-1)at power density of 90 W kg^(-1)in 3 mol L^(-1)ZnSO_(4)electrolyte.It is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF,and further expands the applications of MOF-derived carbons for high-performance energy storage devices,so it is conducive to both pollution alleviation and sustainable economic development.

Analysis of Differences in Electrochemical Performance Between Coin and Pouch Cells for Lithium-Ion Battery Applications

Small coin cell batteries are predominantly used for testing lithium-ion batteries(LIBs)in academia because they require small amounts of material and are easy to assemble.However,insufficient attention is given to difference in cell performance that arises from the differences in format between coin cells used by academic researchers and pouch or cylindrical cells which are used in industry.In this article,we compare coin cells and pouch cells of different size with exactly the same electrode materials,electrolyte,and electrochemical conditions.We show the battery impedance changes substantially depending on the cell format using techniques including Electrochemical Impedance Spectroscopy(EIS)and Galvanostatic Intermittent Titration Technique(GITT).Using full cell NCA-graphite LIBs,we demonstrate that this difference in impedance has important knock-on effects on the battery rate performance due to ohmic polarization and the battery life time due to Li metal plating on the anode.We hope this work will help researchers getting a better idea of how small coin cell formats impact the cell performance and help predicting improvements that can be achieved by implementing larger cell formats.

Local dose-dense chemotherapy for triple-negative breast cancer via minimally invasive implantation of 3D printed devices

Dose-dense chemotherapy is the preferred first-line therapy for triple-negative breast cancer(TNBC),a highly aggressive disease with a poor prognosis.This treatment uses the same drug doses as conventional chemotherapy but with shorter dosing intervals,allowing for promising clinical outcomes with intensive treatment.However,the frequent systemic administration used for this treatment results in systemic toxicity and low patient compliance,limiting therapeutic efficacy and clinical benefit.Here,we report local dose-dense chemotherapy to treat TNBC by implanting 3D printed devices with timeprogrammed pulsatile release profiles.The implantable device can control the time between drug releases based on its internal microstructure design,which can be used to control dose density.The device is made of biodegradable materials for clinical convenience and designed for minimally invasive implantation via a trocar.Dose density variation of local chemotherapy using programmable release enhances anti-cancer effects in vitro and in vivo.Under the same dose density conditions,device-based chemotherapy shows a higher anticancer effect and less toxic response than intratumoral injection.We demonstrate local chemotherapy utilizing the implantable device that simulates the drug dose,number of releases,and treatment duration of the dose-dense AC(doxorubicin and cyclophosphamide)regimen preferred for TNBC treatment.Dose density modulation inhibits tumor growth,metastasis,and the expression of drug resistance-related proteins,including p-glycoprotein and breast cancer resistance protein.To the best of our knowledge,local dose-dense chemotherapy has not been reported,and our strategy can be expected to be utilized as a novel alternative to conventional therapies and improve anti-cancer efficiency.

Recent progress on MOF/MXene nanoarchitectures:A new era in coordination chemistry for energy storage and conversion

The development of urbanization and industrialization leads to rapid depletion of fossil fuels.Therefore,the production of fuel from renewable resources is highly desired.Electrotechnical energy conversion and storage is a benign technique with reliable output and is eco-friendly.Developing an exceptional electrochemical catalyst with tunable properties like a huge specific surface area,porous channels,and abundant active sites is critical points.Recently,Metal-organic frameworks(MOFs)and two-dimensional(2D)transition-metal carbides/nitrides(MXenes)have been extensively investigated in the field of electrochemical energy conversion and storage.However,advances in the research on MOFs are hampered by their limited structural stability and conventionally low electrical conductivity,whereas the practical electrochemical performance of MXenes is impeded by their low porosity,inadequate redox sites,and agglomeration.Consequently,researchers have been designing MOF/MXene nanoarchitectures to overcome the limitations in electrochemical energy conversion and storage.This review explores the recent advances in MOF/MXene nanoarchitectures design strategies,tailoring their properties based on the morphologies(0D,1D,2D,and 3D),and broadening their future opportunities in electrochemical energy storage(batteries,supercapacitors)and catalytic energy conversion(HER,OER,and ORR).The intercalation of MOF in between the MXene layers in the nanoarchitectures functions synergistically to address the issues associated with bare MXene and MOF in the electrochemical energy storage and conversion.This review gives a clear emphasis on the general aspects of MOF/MXene nanoarchitectures,and the future research perspectives,challenges of MOF/MXene design strategies and electrochemical applications are highlighted.

Organic X-Ray Image Sensors Using a Medium Bandgap Polymer Donor with Low Dark Current

The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations.However,this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors.The weight and thickness of X-ray detectors can be reduced by replacing the silicon layer with an organic photodetectors.This study presents a novel bithienopyrroledione-based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer(~700 nm),owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione.The ability of bithienopyrroledione-based polymer donor to strongly suppress the dark current density(Jd~10−10 A cm^(−2))at a negative bias(−2.0 V)while maintaining high responsivity(R=0.29 A W−1)even at a thickness of 700 nm results in a maximum shot-noise-limited specific detectivity of D_(sh)^(*)=2.18×10^(13)Jones in the organic photodetectors.Printed organic photodetectors are developed by slot-die coating for use in X-ray detectors,which exhibit D_(sh)^(*)=2.73×10^(12)Jones with clear rising(0.26 s)and falling(0.29 s)response times upon X-ray irradiation.Detection reliability is also proven by linear response of the X-ray detector,and the X-ray detection limit is 3 mA.

Self-supported VO_(2) on polydopamine-derived pyroprotein-based fibers for ultrastable and flexible aqueous zinc-ion batteries

A conventional electrode composite for rechargeable zinc-ion batteries(ZIBs)includes a binder for strong adhesion between the electrode material and the current collector.However,the introduction of a binder leads to electrochemical inactivity and low electrical conductivity,resulting in the decay of the capacity and a low rate capability.We present a binder-and conducting agent-free VO_(2) composite electrode using in situ polymerization of dopamine on a flexible current collector of pyroprotein-based fibers.The as-fabricated composite electrode was used as a substrate for the direct growth of VO_(2) as a self-supported form on polydopamine-derived pyroprotein-based fibers(pp-fibers@VO_(2)(B)).It has a high conductivity and flexible nature as a current collector and moderate binding without conventional binders and conducting agents for the VO_(2)(B) cathode.In addition,their electrochemical mechanism was elucidated.Their energy storage is induced by Zn^(2+)/H^(+) coinsertion during discharging,which can be confirmed by the lattice expansion,the formation of by-products including Zn_(x)(OTf)_(y)(OH)_(2x−y)·nH_(2)O,and the reduction of V^(4+)to V^(3+).Furthermore,the assembled Zn//pp-fibers@VO_(2)(B) pouch cells have excellent flexibility and stable electrochemical performance under various bending states,showing application possibilities for portable and wearable power sources.

Machine Learning-Assisted Fabrication of PCBM-Perovskite Solar Cells with Nanopatterned TiO_(2)Layer

To unlock the full potential of PSCs,machine learning(ML)was implemented in this research to predict the optimal combination of mesoporous-titanium dioxide(mp-TiO_(2))and weight percentage(wt%)of phenyl-C_(61)-butyric acid methyl ester(PCBM),along with the current density(J_(sc)),open-circuit voltage(V_(oc)),fill factor(ff),and energy conversion efficiency(ECE).Then,the combination that yielded the highest predicted ECE was selected as a reference to fabricate PCBM-PSCs with nanopatterned TiO_(2)layer.Subsequently,the PCBM-PSCs with nanopatterned TiO_(2)layers were fabricated and characterized to further understand the effects of nanopatterning depth and wt%of PCBM on PSCs.Experimentally,the highest ECE of 17.338%is achieved at 127 nm nanopatterning depth and 0.10 wt%of PCBM,where the J_(sc),V_(oc),and ff are 22.877 mA cm^(-2),0.963 V,and 0.787,respectively.The measured J_(sc),V_(oc),ff,and ECE values show consistencies with the ML prediction.Hence,these findings not only revealed the potential of ML to be used as a preliminary investigation to navigate the research of PSCs but also highlighted that nanopatterning depth has a significant impact on J_(sc),and the incorporation of PCBM on perovskite layer influenced the V_(oc)and ff,which further boosted the performance of PSCs.

Research on flexible display at Ulsan National Institute of Science and Technology

Displays represent information visually,so they have become the fundamental building block to visualize the data of current electronics including smartphones.Recently,electronics have been advanced toward flexible and wearable electronics that can be bent,folded,or stretched while maintaining their performance under various deformations.Here,recent advances in research to demonstrate flexible and wearable displays are reviewed.We introduce these results by dividing them into several categories according to the components of the display:active-matrix backplane,touch screen panel,light sources,integrated circuit for fingerprint touch screen panel,and characterization tests;and we also present mechanical tests in nano-meter scale and visual ergonomics research.

Whole-genome,transcriptome,and methylome analyses provide insights into the evolution of platycoside biosynthesis in Platycodon grandiflorus,a medicinal plant

Triterpenoid saponins(TSs)are common plant defense phytochemicals with potential pharmaceutical properties.Platycodon grandiflorus(Campanulaceae)has been traditionally used to treat bronchitis and asthma in East Asia.The oleanane-type TSs,platycosides,are a major component of the P.grandiflorus root extract.Recent studies show that platycosides exhibit anti-inflammatory,antiobesity,anticancer,antiviral,and antiallergy properties.However,the evolutionary history of platycoside biosynthesis genes remains unknown.In this study,we sequenced the genome of P.grandiflorus and investigated the genes involved in platycoside biosynthesis.The draft genome of P.grandiflorus is 680.1 Mb long and contains 40,017 protein-coding genes.Genomic analysis revealed that the CYP716 family genes play a major role in platycoside oxidation.The CYP716 gene family of P.grandiflorus was much larger than that of other Asterid species.Orthologous gene annotation also revealed the expansion ofβ-amyrin synthases(bASs)in P.grandiflorus,which was confirmed by tissue-specific gene expression.In these expanded gene families,we identified key genes showing preferential expression in roots and association with platycoside biosynthesis.In addition,wholegenome bisulfite sequencing showed that CYP716 and bAS genes are hypomethylated in P.grandiflorus,suggesting that epigenetic modification of these two gene families affects platycoside biosynthesis.Thus whole-genome,transcriptome,and methylome data of P.grandiflorus provide novel insights into the regulation of platycoside biosynthesis by CYP716 and bAS gene families.

Controlling the rate of degradation of Mg using magnesium fluoride and magnesium fluoride-magnesium phosphate duplex coatings

The thin and porous Fluoride Conversion Coating FCC with many cracks could not offer a significant improvement in corrosion resistance for Mg. Magnesium phosphate coating improves the corrosion resistance of Mg, good bioactivity, promotes cell viability and cyto-compatibility and exhibits antibacterial activity. However, rapid dissolution in Mg in acidic magnesium phosphate containing solutions leads to the development of an inhomogeneous coating. The present study attempts to prevent the excessive dissolution of Mg by forming a fluoride conversion coating as a pre-treatment in the first stage followed by deposition of magnesium phosphate coating in the second stage to develop magnesium fluoride-magnesium phosphate duplex coatings. The morphological features, structural characteristics, nature of functional groups, corrosion behavior in Hanks’ balanced salt solution and bioactivity in simulated body fluid are assessed to ascertain the suitability of the magnesium fluoride-magnesium phosphate duplex coating in controlling the rate of degradation of Mg and improving its bioactivity using uncoated Mg and fluoride conversion coated Mg as reference. The findings of the study reveal that the magnesium fluoride-magnesium phosphate duplex coating could offer an excellent corrosion resistance and improve the bioactivity of Mg.

Modeling and implementation of tandem polymer solar cells using wide-bandgap front cells

Tandem device architectures offer a route to greatly increase the maximum possible power conversion efficiencies(PCEs)of polymer solar cells,however,the complexity of tandem cell device fabrication(such as selecting bandgaps of the front and back cells,current matching,thickness,and recombination layer optimization)often result in lower PCEs than are observed in single-junction devices.In this study,we analyze the influence of front cell and back cell bandgaps and use transfer matrix modeling to rationally design and optimize effective tandem solar cell structures before actual device fabrication.Our approach allows us to estimate tandem device parameters based on known absorption coefficients and open-circuit voltages of different active layer materials and design devices without wasting valuable time and materials.Using this approach,we have investigated a series of wide bandgap,high voltage photovoltaic polymers as front cells in tandem devices with PTB7-Th as a back cell.In this way,we have been able to demonstrate tandem devices with PCE of up to 12.8%with minimal consumption of valuable photoactive materials in tandem device optimization.This value represents one of the highest PCE values to date for fullerene-based tandem solar cells.

Self-motivated,thermally oxidized hematite nanoflake photoanodes:Effects of pre-polishing and ZrO_(2) passivation layer

High-temperature thermal oxidation of an Fe foil produces a high-quality,crystalline hematite nanoflake suitable as a photoanode for the photoelectrochemical(PEC)water oxidation.Physical pre-polishing of the foil surface has a profound effect in the formation of a vertically-aligned nanoflakes of hematite phase with extended(110)planes by removing the loosely-bonded oxide layer.When the surface of the photoanode is modified with a ZrO_(2) passivation layer and a cobalt phosphate co-catalyst,the charge recombination at the photoanode-electrolyte interface is greatly suppressed to improve its overall PEC activity.As a result,the photocurrent density at 1.10 VRHE under 1 sun condition is enhanced from 0.22 mA cm^(-2) for an unmodified photoanode to 0.59 mA cm^(-2) for the fully modified photoanode,and the photocurrent onset potential is shifted cathodically by 400 mV.Moreover,the photoanode demonstrates outstanding stability by showing steady production of H_(2) and O_(2) gases in the stoichiometric ratio of 2:1 in a continuous PEC operation for 10 h.

Corrosion characteristics of single-phase Mg-3Zn alloy thin film for biodegradable electronics

Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg-Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg-3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg-3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg-3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

The first observation of Ni nanoparticle exsolution from YSZ and its application for dry reforming of methane

Ni nanocatalysts produced through exsolution have shown strong resistance to particle sintering and carbon coking in a beneficial dry reforming of methane(DRM)reaction utilizing greenhouse gases such as CH_(4)and CO_(2).However,most of the existing oxide supports for exsolution have been limited to perovskite oxide,while studies on fluorite support have been rarely conducted due to the limited solubility despite its excellent redox stability.Here we demonstrate that 3 mol%Ni can be successfully dissolved into the yttria-stabilized zirconia(YSZ)lattice and be further exsolved to the surface in a reducing atmosphere.The YSZ decorated with exsolved Ni nanoparticles shows enhanced catalytic activity for DRM reaction compared to the conventional cermet type of bulk Ni-YSZ.Moreover,the catalytic activity is extremely stable for about 300 h without significant degradation.Overall results suggest that the YSZ-based fluorite structure can be utilized as one of the support oxides for exsolution.

Recent Advances in Patterning Strategies for Full‑Color Perovskite Light‑Emitting Diodes

Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with remarkably narrow bandwidths,high quantum yield,and solution processability.Despite recent advances have pushed the luminance efficiency of monochromic perovskite light-emitting diodes(PeLEDs)to their theoretical limits,their current fabrication using the spincoating process poses limitations for fabrication of full-color displays.To integrate PeLEDs into full-color display panels,it is crucial to pattern red–green–blue(RGB)perovskite pixels,while mitigating issues such as cross-contamination and reductions in luminous efficiency.Herein,we present state-of-the-art patterning technologies for the development of full-color PeLEDs.First,we highlight recent advances in the development of efficient PeLEDs.Second,we discuss various patterning techniques of MPHs(i.e.,photolithography,inkjet printing,electron beam lithography and laserassisted lithography,electrohydrodynamic jet printing,thermal evaporation,and transfer printing)for fabrication of RGB pixelated displays.These patterning techniques can be classified into two distinct approaches:in situ crystallization patterning using perovskite precursors and patterning of colloidal perovskite nanocrystals.This review highlights advancements and limitations in patterning techniques for PeLEDs,paving the way for integrating PeLEDs into full-color panels.

A Solvent-Free Covalent Organic Framework Single-Ion Conductor Based on Ion-Dipole Interaction for All-Solid-State Lithium Organic Batteries

Single-ion conductors based on covalent organic frameworks(COFs)have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility.However,the sluggish Li+conduction has hindered their practical applications.Here,we present a class of solvent-free COF single-ion conductors(Li-COF@P)based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction.The ion(Li+from the COF)-dipole(oxygen from poly(ethylene glycol)diacrylate embedded in the COF pores)interaction in the Li-COF@P promotes ion dissociation and Li+migration via directional ionic channels.Driven by this single-ion transport behavior,the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance(88.3%after 2000 cycles)in organic batteries(Li metal anode||5,5’-dimethyl-2,2’-bis-p-benzoquinone(Me2BBQ)cathode)under ambient operating conditions,highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.

Multiphase cooperation for multilevel strain accommodation in a single-crystalline BiFeO_(3) thin film

The functionalities and diverse metastable phases of multiferroic BiFeO_(3)(BFO)thin films depend on the misfit strain.Although mixed phase-induced strain relaxation in multiphase BFO thin films is well known,it is unclear whether a singlecrystalline BFO thin film can accommodate misfit strain without the involvement of its polymorphs.Thus,understanding the strain relaxation behavior is key to elucidating the lattice strain–property relationship.In this study,a correlative strain analysis based on dark-field inline electron holography(DIH)and quantitative scanning transmission electron microscopy(STEM)was performed to reveal the structural mechanism for strain accommodation of a single-crystalline BFO thin film.The nanoscale DIH strain analysis results indicated a random combination of multiple strain states that acted as a primary strain relief,forming irregularly strained nanodomains.The STEM-based bond length measurement of the corresponding strained nanodomains revealed a unique strain accommodation behavior achieved by a statistical combination of multiple modes of distorted structures on the unit-cell scale.The globally integrated strain for each nanodomain was estimated to be close to1.5%,irrespective of the nanoscale strain states,which was consistent with the fully strained BFO film on the SrTiO_(3) substrate.Density functional theory calculations suggested that strain accommodation by the combination of metastable phases was energetically favored compared to single-phase-mediated relaxation.This discovery allows a comprehensive understanding of strain accommodation behavior in ferroelectric oxide films,such as BFO,with various low-symmetry polymorphs.

A recent advances of blue perovskite light emitting diodes for next generation displays

The halide perovskite blue light emitting diodes(PeLEDs)attracted many researchers because of its fascinating optoelectrical properties.This review introduces the recent progress of blue PeLEDs which focuses on emissive layers and interlayers.The emissive layer covers three types of perovskite structures:perovskite nanocrystals(PeNCs),2-dimensional(2D)and quasi-2D perovskites,and bulk(3D)perovskites.We will discuss about the remaining challenges of blue PeLEDs,such as limited performances,device instability issues,which should be solved for blue PeLEDs to realize next generation displays.

Non-conjugated terpolymer acceptors for highly efficient and stable lager-area all-polymer solar cells

All-polymer solar cells(all-PSCs)have made significant progress recently,but few studies have been conducted to investigate the lab-to-manufacturing translation from the spin-coating method to the printing process.Here,the random copolymerization method and non-conjugated backbone approach are integrated to manipulate the morphology and photoelectric properties of the active layer for large-area printed all-PSCs.A series of non-conjugated terpolymer acceptors PYSe-TC_(6)T(x)(x=5,10,and 20,refers to the molar ratio of TC_(6)T unit)are developed by covalently introducing non-conjugated unit TC_(6)T into the PYSe host bipolymer by random copolymerization.The spin-coated PYSe-TC_(6)T(10)-based all-PSC demonstrates the best power conversion efficiency(PCE)of 13.54%,superior to the PYSe-based one(12.45%).More intriguingly,morphological studies reveal that a combination of the random polymerization and non-conjugated backbone strategy can effectively prevent the active layer from overaggregation and improve the film quality during the printing process,thereby minimizing the efficiency and technology gap between spin-coated small-area devices and blade-coated large-area devices.By directly using the same preparation condition of spin-coating,the blade-coated small-area(0.04 cm^(2))delivers a PCE of 12.83%and the large-area(1.21 cm^(2))device achieves a PCE of 11.96%with a small PCE loss.Both PCE value and PCE loss are one of the most outstanding performances of the bladecoated all-PSCs.These findings reveal that a combination of the non-conjugated flexible backbone with random copolymerization to develop non-conjugated terpolymers is an attractive design concept to smoothly realize the lab-to-manufacturing translation.

Black Photoresist for Patterning Pixel Define Layer of Organic Light Emitting Diode with Polyimide as Thermal Stabilizer

In order to improve the visibility for outside use of organic light emitting diodes (OLEDs), the polarized film and black matrix pattern have been used in the small and medium sized OLEDs;however, these cause problem of reducing the emission efficiency of OLED. Changing the color of pixel define layer (PDL) from brown to black is an important point for improving the efficiency and visibility of OLEDs. In this work we studied the photoresist material containing black pigment and the photolithographic process for patterning of black PDL on OLEDs. The black PDL patterns made with our synthesized polyimides as thermal stabilizer were found to give high thermal stability over 300°C.