Two-step high-pressure high-temperature synthesis of nanodiamonds from naphthalene

Nanodiamonds have outstanding mechanical properties,chemical inertness,and biocompatibility,which give them potential in various applications.Current methods for preparing nanodiamonds often lead to products with impurities and uneven morphologies.We report a two-step high-pressure high-temperature(HPHT) method to synthesize nanodiamonds using naphthalene as the precursor without metal catalysts.The grain size of the diamonds decreases with increasing carbonization time(at constant pressure and temperature of 11.5 GPa and 700℃,respectively).This is discussed in terms of the different crystallinities of the carbon intermediates.The probability of secondary anvil cracking during the HPHT process is also reduced.These results indicate that the two-step method is efficient for synthesizing nanodiamonds,and that it is applicable to other organic precursors.

Photodetectors based on inorganic halide perovskites:Materials and devices

The newly emerging metal halide perovskites have attracted considerable attention due to their exceptional optoelectronic properties. This upsurge was initially driven when the power conversion efficiency of perovskite-based photovoltaic devices exceeded 23%. Due to their optoelectronic properties, perovskite materials have also been used in light-emitting diodes, photodetectors, lasers, and memory devices. This study comprehensively discusses the recent progress of allinorganic perovskite-based photodetectors, focusing on their structures, morphologies of their constituent materials, and diverse device architectures that improve the performance metrics of these photodetectors. A brief outlook, highlighting the main existing problems, possible solutions to these problems, and future development directions, is also provided herein.

Deep-ultraviolet and visible dual-band photodetectors by integrating Chlorin e6 with Ga_(2)O_(3)

Gallium oxide(Ga_(2)O_(3))is a promising material for deep-ultraviolet(DUV)detection.In this work,Chlorin e6(Ce6)has been integrated with Ga_(2)O_(3)to achieve a DUV and visible dual-band photodetector,which can achieve multiple target information and improve the recognition rate.The photodetector shows two separate response bands at 268 nm and 456 nm.The DUV response band has a responsivity of 9.63 A/W with a full width at half maximum(FWHM)of 54.5 nm;the visible response band has a responsivity of 1.17 A/W with an FWHM of 45.3 nm.This work may provide a simple way to design and fabricate photodetectors with dual-band response.

One-dimensional sp carbon:Synthesis,properties,and modifications

Carbyne,as the truly one-dimensional carbon allotrope with sp-hybridization,has attracted significant interest in recent years,showing potential applications in next-generation molecular devices due to its ultimate one-atom thinness.Various excellent properties of carbyne have been predicted,however,free-standing carbyne sample is extremely unstable and the corresponding experimental researches and modifications are under-developed compared to other known carbon allotropes.The synthesis of carbyne has been slowly developed for the past decades.Recently,there have been several breakthroughs in in-situ synthesis and measurement of carbyne related materials,as well as the preparation of ultra-long carbon chains toward infinite carbyne.These progresses have aroused widespread discussion in the academic community.In this review,the latest approaches in the synthesis of sp carbon are summarized.We then discuss its extraordinary properties,including mechanical,electronic,magnetic,and optical properties,especially focusing on the regulations of these properties.Finally,we provide a perspective on the development of carbyne.

Silica encapsulated ZnO quantum dot-phosphor nanocomposites:Sol-gel preparation and white light-emitting device application

ZnO quantum dots （QDs） as an eco-friendly and low-cost material has bright fluorescence, which makes it promising material for healthy lighting and displaying. However, the low fluorescence efficiency and poor stability of ZnO QDs impede their applications in lighting application. In this work, silica encapsulated ZnO QD-phosphors nanocomposites （ZSPN） have been prepared through a sol-gel synthesis process, where yellow-emitting ZnO QDs and blue-emitting BaMgAl10O17：Eu2＋ are employed as the luminescence cores and silica as link between two luminescence materials. Tunable photoluminescence of ZSPN and the white light emission have been achieved through changing mass ratio of both of ZnO QDs and commercial phosphors. The PLQY of the ZSPN can reach 63.7% and they can maintain high luminous in- tensity even the ambient temperature up to 110 ℃ and after 35 h of UV irradiation. In addition, they can keep stable for 40 days. By coating the ZSPN phosphors onto a ultraviolet chip, WLEDs with luminous efficiency of 73.6 lm/W and the color coordinate, correlated color temperature, and color rendering index can reach （0.32, 0.34）, 5580 K, and 87, respectively, indicating the bright prospect of the ZSPN phosphors used in healthy lighting.

Rational design multi-color-emissive chemiluminescent carbon nanodots in a single solvothermal reaction

Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism.Herein,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction.More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and core-states.Thus,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information encryption.This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.

Work-function effect of Ti_(3)C_(2)/Fe-N-C inducing solid electrolyte interphase evolution for ultra-stable sodium storage

In the quest to enhance the efficiency of sodium-ion batteries,the dynamics of solid electrolyte interphase(SEI)formation are of paramount importance.The SEI layer’s integrity is integral to the charge–discharge efficiency and the overall longevity of the battery.Herein,a novel two-dimensional Ti_(3)C_(2) fragments enmeshed on iron-nitrogen-carbon(Fe-N-C)nanosheets(Ti_(3)C_(2)/Fe-NC)has been synthesized.This electrode features a matrix which has been shown to expedite SEI layer formation through the facilitation of selective anion adsorption,thus augmenting battery performance.Density functional theory calculation reveals that the SEI evolution energy of NaPF6 at the Ti_(3)C_(2)/Fe-N-C interface is 0.81 eV,significantly lower than the Ti_(3)C_(2)(1.23 eV).This process is driven by the electron transportation from Ti_(3)C_(2) to Fe-N-C substrate,facilitated by their work-function difference,leading to the formation of ferromagnetic Fe species,which possesses Fe 3d d_(xz)d_(z)2 orbitals and undergoes hybridization with theπandσorbitals of NaF,creating a key intermediate during charging.This process diminishes the antibonding energy and attenuates the orbital interaction with NaF,thus reducing the activation energy and improving the SEI formation reaction kinetics.Consequently,it leads to the creation of multi-interface SEI characterized by high-throughput ion transport and an efficient reaction network.

Cationic engineered nanodiamonds for efficient antibacterial surface with strong wear resistance

The spread of diseases caused by bacterial adhesion and immobilization in public places constitutes a serious threat to public health.Prevention of bacteria spread by the construction of an antibacterial surface takes precedence over post-infection treatment.Herein,we demonstrate an effective antibacterial surface with strong wear resistance by constructing cationic engineered nanodiamonds(C-NDs).The C-NDs with positive surface potentials interact effectively with bacteria through electrostatic interactions,where the C-NDs act on the phospholipid bilayer and lead to bacterial membrane collapse and rupture through hydrogen bonding and residual surface oxygen-containing reactive groups.In this case,bactericidal rate of 99.99%and bacterial biofilm inhibition rate of more than 80%can be achieved with the C-NDs concentration of 1 mg/mL.In addition,the C-NDs show outstanding antibacterial stability,retaining over 87%of the antibacterial effect after stimulation by adverse environments of heat,acid,and external abrasion.Therefore,an antibacterial surface with high wear resistance obtained by integrating C-NDs with commercial plastics has been demonstrated.The antibacterial surface with a mass fraction of 1 wt.%C-NDs improved abrasion resistance by 3981 times,with 99%killing of adherent bacteria.This work provides an effective strategy for highly efficient antibacterial wear-resistant surface,showing great practical applications in public health environments.

Triggering triplet excitons of carbon nanodots through nanospace domain confinement for multicolor phosphorescence in aqueous solution

Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings.Recently reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots(CNDs)is still a challenging issue.Herein,full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement,and Förster energy resonance transfer is used for further tuning phosphorescence range.The phosphorescence spans across most of the visible spectrum,ranging from 400 to 700 nm.In an aqueous solution,the CNDs exhibits blue,green,and red phosphorescence,lasting for approximately 6,10,and 7 s,respectively.Correspondingly,the phosphorescence quantum yields are 11.85%,8.6%and 3.56%,making them readily discernible to the naked eyes and laying a solid foundation for practical application.Furthermore,phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials,showing distinct superiority for accuracy and complete display and imaging in complex emission background.

Sensitive humidity sensor based on moisture-driven energy generation

The emergence of novel self-powered humidity sensors has attracted considerable attention in the fields of smart electronic devices and personal healthcare.Herein,self-powered humidity sensors have been fabricated using a moisture-driven energy generation(MEG)device based on asymmetric tubular graphitic carbon nitride(g-CN)films prepared on anodized aluminum(AAO)template.At a relative humidity(RH)of 96%,the MEG device can provide an open-circuit voltage of 0.47 V and a short-circuit current of 3.51μA,with a maximum output power of 0.08μW.With inherent self-powered ability and humidity response via current variation,an extraordinary response of 1.78×106%(41%-96%RH)can be gained from the MEG device.The possible power generation mechanism is that g-CN/AAO heterostructure can form ion gradient and diffusion under the action of moisture to convert chemical potential into electrical potential,evoking a connaturally sensitive response to humidity.Self-powered respiration monitoring device based on the sensor is designed to monitor human movement(sitting,warming up,and running)and sleep status(normal,snoring,and apnea),maintaining excellent stability during cumulative 12-h respiration monitoring.This self-powered humidity sensing technology has promising potential for extensive integration into smart electronic and round-the-clock health monitoring devices.

Theoretical study of superradiant masing with solid-state spins at room temperature

Steady-state superradiance and superradiant lasing attract significant attentions in the field of optical lattice clocks,but have not been achieved yet due to the technical challenges and atom loss problem.In this article,we propose that their counter-part may be observed in the microwave domain with solid-state spins,i.e.,nitrogen-vacancy center spins and pentacene molecular spins,coupled to microwave resonator at room temperature with realistic technical restrictions.To validate our proposal,we investigate systematically the system dynamics and steady-state by solving quantum master equations for the multi-level and multi-process dynamics of trillions of spins.Our calculations show that the superradiant Rabi oscillations occur firstly due to transitions among different Dicke states,and the subsequent continuous-wave superradiant masing can achieve a linewidth well below millihertz.Our work may guide further exploration of transient and steady-state superradiant masing with the mentioned and other solid-state spins systems.The ultra-narrow linewidth may find applications in deep-space communications,radio astronomy and high-precision metrology.

Phase-controlled van der Waals growth of wafer-scale 2D MoTe_(2) layers for integrated high-sensitivity broadband infrared photodetection

Being capable of sensing broadband infrared(IR)light is vitally important for wide-ranging applications from fundamental science to industrial purposes.Two-dimensional(2D)topological semimetals are being extensively explored for broadband IR detection due to their gapless electronic structure and the linear energy dispersion relation.However,the low charge separation efficiency,high noise level,and on-chip integration difficulty of these semimetals significantly hinder their further technological applications.Here,we demonstrate a facile thermal-assisted tellurization route for the van der Waals(vdW)growth of wafer-scale phase-controlled 2D MoTe_(2)layers.Importantly,the type-ⅡWeyl semimetal 1T'-MoTe_(2)features a unique orthorhombic lattice structure with a broken inversion symmetry,which ensures efficient carrier transportation and thus reduces the carrier recombination.This characteristic is a key merit for the well-designed 1T'-MoTe_(2)/Si vertical Schottky junction photodetector to achieve excellent performance with an ultrabroadband detection range of up to 10.6μm and a large room temperature specific detectivity of over 108 Jones in the mid-infrared(MIR)range.Moreover,the large-area synthesis of 2D MoTe_(2)layers enables the demonstration of high-resolution uncooled MIR imaging capability by using an integrated device array.This work provides a new approach to assembling uncooled IR photodetectors based on 2D materials.

Continuous synthesis of ultra-fine fiber for wearable mechanoluminescent textile

Continuous mechanoluminescence(ML)fibers and fiber-woven textiles have the potential to serve as new wearable devices for sensors,healthcare,human-computer interfacing,and Internet of Things.Considering the demands on wearability and adaptability for the ML textiles,it is essential to realize the continuous synthesis of fiber,while maintaining a desired small diameter.Here,we develop a novel adhere-coating method to fabricate ML composite fiber,consisting of a thin polyurethane(PU)core and ZnS:Cu/polydimethylsiloxane(PDMS)shell,with the outer diameter of 120μm.By diluting PDMS to tune the thickness of liquid coating layer,droplets formation has been effectively prevented.The composite fiber exhibits a smooth surface structure and superior ML performances,including high brightness,excellent flexibility,and stability.In addition,a weft knitting textile fabricated by the continuous ML fiber can be easily delighted by manually stretching,and the ML fibers can emit visible signals upon human motion stimuli when woven into commercial cloth.Such continuous ultra-fine ML fibers are promising as wearable sensing devices for human motion detection and human-machine interactions.

Chemiluminescent carbon nanodots for dynamic and guided antibacteria

Advanced antibacterial technologies are needed to counter the rapid emergence of drug-resistant bacteria.Imageguided therapy is one of the most promising strategies for efficiently and accurately curing bacterial infections.Herein,a chemiluminescence(CL)-dynamic/guided antibacteria(CDGA)with multiple reactive oxygen species(ROS)generation capacity and chemiexcited near-infrared emission has been designed for the precise theranostics of bacterial infection by employing near-infrared emissive carbon nanodots(CDs)and peroxalate as CL fuels.Mechanistically,hydrogen peroxide generated in the bacterial microenvironment can trigger the chemically initiated electron exchange between CDs and energy-riched intermediate originated from the oxidized peroxalate,enabling bacterial induced inflammation imaging.Meanwhile,type Ⅰ/Ⅱ photochemical ROS production and type Ⅲ ultrafast charge transfer from CDs under the self-illumination can inhibit the bacteria proliferation efficiently.The potential clinical utility of CDGA is further demonstrated in bacteria infected mice trauma model.The self-illuminating CDGA exhibits an excellent in vivo imaging quality in early detecting wound infections and internal inflammation caused by bacteria,and further are proven as efficient broad-spectrum antibacterial nanomedicines without drug-resistance,whose sterilizing rate is up to 99.99%.

Ultrasensitive broadband position-sensitive detector based on graphitic carbon nitride

As a typical two-dimensional material,graphitic carbon nitride(g-CN)has attracted great interest because of its distinctive electronic,optical,and catalytic properties.However,the absence of a feasible route toward large-area and high-quality films hinders its development in optoelectronics.Herein,high-quality g-CN films have been grown on Si substrate via a vapor-phase transport-assisted condensation method.The g-CN/Si heterojunction shows an obvious response to ultraviolet–visible-near infrared photons with a responsivity of 133 A·W−1,which is two orders of magnitude higher than the best value ever reported for g-CN photodetectors.A position-sensitive detector(PSD)has been developed using the lateral photovoltaic effect of the g-CN/Si heterojunction.The PSD shows a wide response spectrum ranging from 300 to 1,100 nm,and a position sensitivity and rise/decay time of 395 mV·mm−1 and 3.1/50μs,respectively.Moreover,the application of the g-CN/Si heterojunction photodetector in trajectory tracking and acoustic detection has been realized for the first time.This work unveils the potential of g-CN for large-area photodetectors,and prospects for their applications in trajectory tracking and acoustic detection.

Viral inactivation by irradiation rays

Viral infection can lead to serious illness and death around the world,as exemplified by the spread of COVID-19.Using irradiation rays can inactive virions through ionizing and non-ionizing effect.The application of light in viral inactivation and the underlying mechanisms are reviewed by the research group of Dayong Jin from University of Technology Sydney.

Biomass-derived washable composites for accelerating the healing of infected wounds

Advanced sustainable biomedical materials are urgently needed for clinical applications;however,developing biomedical materials with exceptional mechanical and bactericidal properties as well as removable functionalities to reduce unintended secondary injury remains a challenge.Here,we report a biomass-derived composite consisting of water-soluble fish gelatin(FG)and antibacterial ZnO@silk fibroin(ZSF)microspheres for potential application as the wound dressing.The ZSF microspheres are embedded in a FG matrix to realize the stretchable,antibacterial,and removable ZSF/FG composites.By introducing glycerin as the plasticizer,ZSF/FG composites deliver a tensile strength of 4.5 MPa and stretchability of 550%.Acting as both the germicide and hydrophile components,ZSF microspheres endow the composites with excellent antibacterial capacity and water solubility.To prevent secondary injury,the ZSF/FG composites can be easily removed from the wounds by simply exposing them to excess water.Additionally,the ZSF/FG composites exhibit favorable biocompatibility and sustain high cell viability of over 100%.The full-thickness skin wound model on infected mice demonstrated an efficient rate of wound closure and a reduced inflammatory response.The ZSF/FG composite shows promise to hasten the healing of infected wounds and is expected a promising candidate as wound dressing for clinical therapy.

A flexible and superhydrophobic upconversionluminescence membrane as an ultrasensitive fluorescence sensor for single droplet detection

A Ln^(3+)-doped(Yb^(3+),Tm^(3+)or Yb^(3+),Er^(3+)co-doped)NaYF4 nanoparticle/polystyrene hybrid fibrous membrane(HFM)was fabricated using an electrospinning technique.The HFM shows upconversion luminescence(UCL),flexibility,superhydrophobicity and processability.The UCL membrane can be used as a fluorescence sensor to detect bioinformation from a single water droplet(~10μl).Based on the fluorescence resonance energy transfer,the detection limits of this sensor can reach 1 and 10 ppb for the biomolecule,avidin,and the dye molecule,Rhodamine B,respectively,which are superior to most of the fluorescence sensors reported in previous works.After the fluorescence detection,the target droplet was easily removed without residues on the UCL membrane surface due to its superhydrophobic property,which exhibits an excellent recyclability that cannot be achieved by traditional liquid-based detection systems.

Water-induced ultralong room temperature phosphorescence by constructing hydrogen-bonded networks

Room temperature phosphorescence(RTP)materials show potential applications in information security and optoelectronic devices,but it is still a challenge to achieve RTP in organic materials under water ambient due to the unstable property of triplet states.Herein,water-induced RTP has been demonstrated in the organic microrod(OMR).Noting that the RTP intensity of the as-prepared OMR is greatly enhanced when water is introduced,and the reason for the enhancement can be attributed to the formation of hydrogen-bonded networks inside the OMR.The hydrogen-bonded networks can confine the molecular motion effectively,leading to the stability of triplet states;thus the lifetime of the OMR can reach 1.64 s after introducing water.By virtue of the long lifetime of the OMR in the presence of water,multilevel data encryption based on the OMR has been demonstrated.

Self-exothermic reaction driven large-scale synthesis ofphosphorescent carbon nanodots

Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’self-exothermic reaction at room temperature.The as-prepared CNDs show fluorescence and phosphorescence property,which are comparable with that synthesized by solvothermal and microwave method.Experimental and computational studies indicate that exotic atom doped sp^(2) hybridized carbon core works as an emissive center,which facilities the intersystem crossing from singlet state to triplet state.The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures.The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.