Boosted Near-Infrared Photothermal Conversion in Rare Earth Ions-Doped 2D SnSe Nanosheets for Solar-Powered Water Evaporation Systems.

Solar-powered water evaporation as a clean and abundant renewable energy-efficient desalination technology provides a promising strategy to solve the shortage of freshwater resources. However, the development and application of solar vapor technology are hindered by the relatively low near-infrared photothermal conversion efficiency of existing materials and the lack of effective improvement strategies. In this work, the conductivity characteristics of 2D semiconductors are capitalized on the high visible light absorption and ultra-low thermal. Specifically, rare-earth ion dopants into SnSe nanosheets, significantly boosting their near-infrared photothermal conversion efficiency and solar water evaporation performance are introduced. Remarkably, the photothermal conversion efficiency of the doped SnSe nanosheets surged from 51.56% to 82.11%, surpassing many previously reported photothermal materials. Furthermore, leveraging these nanosheets with enhanced photothermal conversion efficiency, a solar interfacial evaporation system is constructed. The evaporation rate of 2.17 kg m-2 h-1 and the efficiency of 96.5% can be achieved at one solar irradiance, and it also has good salt-resistance properties. The findings demonstrate the potential of rare earth ion-doped 2D semiconductor nanosheets in solar water evaporation, paving the way for future sustainable desalination solutions.

Efficient Solar-Driven Interfacial Water Evaporator using Hydrogel Modified Carbon-Based Biomass with Abundant Microchannels.

The conventional sea water desalination technologies are not yet adopted worldwide, especially in the third world countries due to their high capital cost as well as large energy requirement. To solve this issue in a sustainable way an interfacial solar water evaporation device is designed and proposed in this article using the branches of Prunus serrulata (PB). The PB has abundant microchannels and shows excellent photothermal conversion capability after carbonization. Moreover, the easy access to raw materials and the facile fabrication process makes the solar water evaporating device very cost effective for seawater desalination application. Experiments show that in the presence of the fabricated evaporator the evaporation rate of water can reach 3.5 kg m-2 h-1 under 1 sun, which is superior to many similar experimental devices. In addition, its advantages, such as effective sewage purification capability, low cost, and environmental friendliness, make this evaporator highly competitive in the extensive promotion of this technology and can be considered as a new sustainable solution for seawater desalination with great application potential and prospects.

Research on optical performance of Ln2O2S:Er3+/Yb3+ (Ln = La/Gd/Y) phosphors based on different phonon energies.

It is crucial to explore the intrinsic mechanisms that influence thermometric sensitivity. This study investigates the optical performance of materials with the same crystal structure but different phonon energies. Ln2O2S:Er3+/Yb3+ (Ln = La/Gd/Y) phosphors with similar morphology and particle sizes were prepared to systematically study the influence of different phonon energy matrices on optical properties. The intrinsic mechanism was elucidated through the matching degree between the energy gap and phonon energy, Judd-Ofelt (J-O) theory, and quantum dielectric theory. It was ultimately concluded that the combination of high phonon energy with a large Ω2 and a small Ω6 is beneficial for enhancing the sensitivity of temperature sensing materials.

Blue and white light modulation of a flexible electroluminescent device based on phosphors.

Flexibility, certain mechanical strength, and color modulation are significant elements for flexible optoelectronic devices. However, it is laborious to fabricate a flexible electroluminescent device with balanceable flexibility and color modulation. Here, we mix a conductive nonopaque hydrogel and phosphors to fabricate a flexible alternating current electroluminescence (ACEL) device with color modulation ability. This device realizes flexible strain based on polydimethylsiloxane and carboxymethyl cellulose/polyvinyl alcohol ionic conductive hydrogel. The color modulation ability is achieved by varying the voltage frequency applied on the electroluminescent phosphors. The color modulation could realize blue and white light modulation. Our electroluminescent device exhibits great potential in artificial flexible optoelectronics.

Nonvolatile modulation of luminescence in perovskite oxide thin films by ferroelectric gating.

Nonvolatile and giant modulation of luminescence can be realized by the ferroelectric gating effect in a Ga3+/Pr3+ co-doped BaTiO3 ultra-thin film epitaxially grown on a [Pb(Mg1/3Nb2/3)O3]0.7-[PbTiO3]0.3 single-crystallized substrate. The change behavior of the emission intensity matches that of the ferroelectric polarization hysteresis loop with a giant enhancement of over 13 times with negative polarization orientation. The interaction of O2- at the O2p orbital in the valence band and Pr3+ with injected holes by the ferroelectric gating effect promotes the formation of excited state O-, Pr4+, or Pr3+q. This ferroelectric gating method can promote the development of controllable photo-, electroluminescent, and other optoelectronic devices for display, sensing, communication, and so on.

Bio-Derived Photothermal Materials and Evaporators for Sustainable Solar Energy-Driven Water Process.

Interfacial solar steam generation (ISSG) is considered as an excellent seawater desalination technology because of its electricity-independent nature, low cost, and portability. However, improving the water evaporation efficiency, simplifying the fabrication process, and reducing the overall cost of the evaporator are still challenging. Here, an efficient and sustainable solar water evaporator is fabricated with carbonized ginkgo biloba leaves as the structural basis of photothermal materials. The combination of the abundant capillary channels in ginkgo leaves paired with polyacrylamide (PAM) hydrogel accelerates water transportation and solar-driven evaporation. The fabricated evaporator shows excellent photothermal conversion capability and evaporates water at 2.39 kg m-2 h-1 under 1 sun irradiation. In addition, the device exhibits remarkable stability in simulated seawater and can effectively realize seawater desalination or sewage treatment. As a result, the system is promising for future highly efficient solar evaporation due to its environmental protection and low cost.

Ratiometric thermometry using single Er3+-doped CaWO4phosphors.

Single doped CaWO4:Er3+phosphors were synthesized and studied for application of optical thermal sensing within a wide range of 98-773 K. Ratiometric strategy utilizing two luminescence intensity ratios, one between host and Er3+band (LIR1) and second between different Er3+transitions (LIR2), results in self-referencing temperature readouts. The presence of two temperature-dependent parameters could improve thermometric characteristics and broaden the working temperature range compared to a usual single-parameter thermometer. Thermometric performances of prepared samples were evaluated in terms of thermal sensitivities, temperature resolution and repeatability. The highest sensitivity of 2.09% K-1@300 K was found for LIR1, whereas LIR2provided more accurate thermal sensing with a temperature resolution of 0.06-0.1 K. Effect of Er3+doping concentration on sensing properties were studied. The presented findings indicate that CaWO4:Er3+phosphors are perspective in dual-mode thermal sensing with high sensitivity and sub-degree resolution.

Double-doped YVO4 nanoparticles as optical dual-center ratiometric thermometers.

Crystalline inorganic nanoparticles doped with rare earth ions are widely used in a variety of scientific and industry applications due to the unique spectroscopic properties. The temperature dependence of their luminescence parameters makes them promising candidates for self-referencing thermal sensing. Here we report single phase YVO4 nanoparticles doped with different pairs of rare earth ions (Nd3+/Er3+, Tm3+/Er3+ and Nd3+/Tm3+) for contactless ratiometric thermometry within a wide temperature range of 298-573 K. The presence of dual luminescence centers in the optical thermometer allows one to circumvent the fundamental limitation of sensitivity inherent to thermometers based on thermally coupled levels. Important parameters for temperature sensing, such as relative thermal sensitivity and temperature resolution, were calculated for all synthesized samples and compared with the literature data. The YVO4:Tm3+,Er3+ sample displayed a relative sensitivity of 0.28% K-1 at room temperature, and the YVO4:Nd3+,Er3+ phosphor exhibited a high sensitivity of 0.56% K-1 at 573 K, while YVO4:Nd3+,Tm3+ demonstrated sub-degree thermal resolution. These findings demonstrate the good potential of dual-center ratiometric YVO4 thermometers and open the way toward future enhancement of their thermometric performances through variation of the doping concentration.

Reconfigurable hybrid silicon waveguide Bragg filter using ultralow-loss phase-change material.

Reconfigurable silicon photonic devices attract much research attention, and hybrid integration with tunable phase-change materials (PCMs) exhibiting large refractive index contrast between amorphous (Am) and crystalline (Cr) states is a promising way to achieve this goal. Here, we propose and numerically investigate a Sb2Se3-Si hybrid waveguide Bragg filter operating in the telecom C-band on the silicon-on-insulator (SOI) platform. The proposed device consists of a Bragg grating (BG) with a thin top layer of ultralow-loss Sb2Se3 PCM interacting with evanescent field of the silicon waveguide mode. By harnessing the ultralow-loss and reversible index change of Sb2Se3 film, the spectral response of the hybrid BGs could be dynamically tuned. We also theoretically investigate the reversible phase transitions between Am and Cr states of Sb2Se3 film that could be attained by applying voltage pulses on the indium-tin-oxide (ITO) strip heater covered on Sb2Se3 film. Thermal simulations show that a 2 V (4.5 V) pulse with a duration of 400 ns (55 ns) applied to electric contacts would produce crystallization (or amorphization). The proposed structure may find great potential for on-chip phase tunable devices on a silicon platform.

Multi-Responsive Sensor Based on Porous Hydrogen-Bonded Organic Frameworks for Selective Sensing of Ions and Dopamine Molecules.

Hydrogen-bonded organic frameworks (HOFs), as an emerging porous material, have attracted increasing research interest in fluorescence sensing due to their inherent fluorescence emission units with unique physicochemical properties. Herein, based on the organic building block 3,3',5,5'-tetrakis-(4-carboxyphenyl)-1,1'-biphenyl (H4TCBP), the porous material HOF-TCBP was successfully synthesized using hydrogen bond self-assembly in a DMF solution. The fluorescence properties of the HOF-TCBP solution showed that when the concentration was high, excimers were easily formed, the PL emission was red-shifted, and the fluorescence intensity became weaker. HOF-TCBP showed good sensitivity and selectivity to metal ions Fe3+, Cr3+, and anion Cr2O72-. In addition, HOF-TCBP can serve as a label-free fluorescent sensor material for the sensitive and selective detection of dopamine (DA). HOF-based DA sensing is actually easy, low-cost, simple to operate, and highly selective for many potential interfering substances, and it has been successfully applied to the detection of DA in biological samples with satisfactory recoveries (101.1-104.9%). To our knowledge, this is the first report of HOF materials for efficient detection of the neurotransmitter dopamine in biological fluids. In short, this work widely broadens the application of HOF materials as fluorescent sensors for the sensing of ions and biological disease markers.

Yb/Ho Codoped Layered Perovskite Bismuth Titanate Microcrystals with Upconversion Luminescence: Fabrication, Characterization, and Application in Optical Fiber Ratiometric Thermometry.

Optical thermometry has attracted great interest owing to its noncontact and fast responsive properties in practical applications. However, some sensing errors may occur in many optical ratiometric thermometers due to the overlap of emission peaks, suggesting the necessity of developing excellent luminescent materials. Here, we report the fabrication and characterization of Bi4Ti3O12:Yb/Ho for ratiometric thermometry. Bismuth titanate was selected as the matrix due to its low phonon energy, high machinability, and satisfactory thermal stability. The temperature sensing was constructed on the intensity ratio of the two upconversion emission bands with wide separation in Bi4Ti3O12:Yb/Ho under 980 nm excitation. The wide separation endows the materials with high signal discrimination for temperature detection. The developed materials were characterized in terms of crystal structure, reflectance, and emission spectra for thermometry application. The maximum relative sensitivity was shown to be as high as 2.11% K-1. More importantly, an optical fiber thermometry was developed based on the fabricated microcrystals, which can find its potential applications in harsh environments.

Tuning of near-infrared-to-near-infrared luminescence from one-photon to two-photon anti-Stokes shift in Ca3Ga2- xCrxGe3O12 via varying Cr3+ content.

Near-infrared-to-near-infrared (NIR-to-NIR) anti-Stokes luminescence from Cr3+ singly doped Ca3Ga2Ge3O12 (CGGG) occurs under the excitation of an 808 nm diode laser. The anti-Stokes processes vary from one photon to two photon, depending on the Cr3+ content (x) in Ca3Ga2-xCrxGe3O12. The results suggest that phonon-assisted anti-Stokes excitation and cooperative energy transfer are involved in the observed upconversion (UC) processes of CGGG:Cr3+. The relevant Cr3+-doping-concentration-dependent NIR-to-NIR anti-Stokes luminescent mechanism, either one-photon or two-photon UC, is investigated. Such an observation on modulating the UC process via varying the doping concentration is helpful in broadening the understanding of UC phenomena.

Stimuli responsive upconversion luminescence nanomaterials and films for various applications.

Upconversion luminescence (UCL) refers to nonlinear optical processes, which can convert near-infrared photons to short-wavelength emission. Recent advances in nanotechnology have contributed to the development of photon upconversion materials as promising new generation candidates of fluorescent bioprobes and spectral converters for biomedical and optoelectronic applications. Apart from the remarkable photoluminescence of the materials under photon excitation, some UCL materials may exhibit intrinsic magnetic, ferroelectric, X-ray absorption properties, and so on. These interesting characteristics provide an opportunity for us to couple a single stimulus or multiple stimuli (electric field, magnetic field, X-ray, electron beam, temperature and pH, etc.) to various types of UCL materials. In this review, we will primarily focus on the stimuli responsive properties of UCL materials beyond light-matter interaction, which can aid both fundamental research and widespread applications of the materials. The mechanisms of the response to various stimuli in the UCL materials are discussed. This article will also highlight recent advances in the development of these materials in response to various stimuli and their applications in multimodal bioimaging, drug delivery and release, electro-optical devices, magnetic, temperature and pH sensors and multiple anti-counterfeiting inks. Lastly, we will present potential directions of future research and challenging issues which arise in expanding the applications of stimuli responsive UCL materials.

Mapping live cell viscosity with an aggregation-induced emission fluorogen by means of two-photon fluorescence lifetime imaging.

Intracellular viscosity is a crucial parameter that indicates the functioning of cells. In this work, we demonstrate the utility of TPE-Cy, a cell-permeable dye with aggregation-induced emission (AIE) property, in mapping the viscosity inside live cells. Owing to the AIE characteristics, both the fluorescence intensity and lifetime of this dye are increased along with an increase in viscosity. Fluorescence lifetime imaging of live cells stained with TPE-Cy reveals that the lifetime in lipid droplets is much shorter than that from the general cytoplasmic region. The loose packing of the lipids in a lipid droplet results in low viscosity and thus shorter lifetime of TPE-Cy in this region. It demonstrates that the AIE dye could provide good resolution in intracellular viscosity sensing. This is also the first work in which AIE molecules are applied in fluorescence lifetime imaging and intracellular viscosity sensing.

Effect of biaxial strain induced by piezoelectric PMN-PT on the upconversion photoluminescence of BaTiO3:Yb/Er thin films.

Thin films of Yb3+/Er3+ co-doped BaTiO3 (BTO:Yb/Er) have been epitaxially grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Biaxial strain can be effectively controlled by applying electric field on PMN-PT substrate. A reversible, in situ and dynamic modification of upconversion photoluminescence in BTO:Yb/Er film was observed via converse piezoelectric effect. Detailed analysis and in situ X-ray diffraction indicate that such modulations are possibly due to the change in the lattice deformation of the thin films. This result suggests an alternative method to rationally tune the upconversion emissions via strain engineering.

Enhanced broadband excited upconversion luminescence in Ho-doped glasses by codoping with bismuth.

We report enhanced green and red upconversion (UC) luminescence in Ho3+-doped oxyfluoride germanate glass by introducing bismuth near-infrared active centers as sensitizers. The UC excitation bands at 750 and 970 nm show a full width at half-maximum of 20 and 45 nm, respectively. Energy transfer from sensitizers, the excited-state absorption, and phonon-coupled absorption of Ho3+ jointly contribute to the enhanced UC luminescence. Our approach provides an efficient methodology to broaden the excitation bandwidth of UC luminescent materials, which may have the potential for promising application in solar cells.

Ultrasonic-driven degradation of organic pollutants using piezoelectric catalysts WS2/Bi2WO6 heterojunction composites.

Water pollution has been made worse by the widespread use of organic dyes and their discharge, which has coincided with the industry's rapid development. Piezoelectric catalysis, as an effective wastewater purification method with promising applications, can enhance the catalyst activity by collecting tiny vibrations in nature and is not limited by sunlight. In this work, we designed and synthesized intriguing WS2/Bi2WO6 heterojunction nanocomposites, investigated their shape, structure, and piezoelectric characteristics using a range of characterization techniques, and used ultrasound to accelerate the organic dye Rhodamine B (RhB) degradation in wastewater. In comparison to the pristine monomaterials, the results demonstrated that the heterojunction composites demonstrated excellent degradation and stability of RhB under ultrasonic circumstances. The existence of heterojunctions and the internal piezoelectric field created by ultrasonic driving work in concert to boost catalytic performance, and the organic dye's rate of degradation is further accelerated by the carriers that are mutually transferred between the composites.

Multi-Mode Luminescence in Smart Near-Infrared Cr3+/Pr3+ Codoped SrGa12O19 Phosphors Induced by Three Distinct Excitation Mechanisms.

Near-infrared (NIR) phosphors have emerged as novel luminescent materials across various fields due to their unique advantages of high penetration and invisibility. However, there is currently a lack of intelligent NIR phosphors that can achieve multimode stimuli responsive for sensing applications. In this study, we employed a high-temperature solid-phase reaction to incorporate Pr3+ into Cr3+-doped gallate magnetite SrGa12O19 phosphor, yielding a multimode luminescent intelligent NIR phosphor. Also, due to the inherent cation vacancies and defects in the matrix, the material not only exhibits brighter photoluminescence but also exhibits distinct NIR mechanoluminescence at a lower load. Notably, Pr3+-doped SrGa12O19:Cr3+ also demonstrates extended persistent luminescence and thermoluminescence effects. Finally, we combined the phosphor with the blue LED chip to develop a new multifunctional NIR pc-LED. Leveraging NIR's unique penetrating ability, it can persist in biological tissues for prolonged periods, enabling optical inspection and offering a novel approach to password protection for anticounterfeiting measures. This intelligent NIR phosphor solution significantly expands the application potential of NIR light in food quality assessment and analysis.

Self-Powered and Self-Recovered Mechanoluminescent Electronic Skins for Detecting and Distinguishing Diverse External Stimuli.

The concept of simulating external mechanical stimuli to generate luminescence has been a long-standing aspiration in real-time dynamic visualization. However, creating self-power and self-restoring mechanoluminescent electronic skins for artificial sensors poses significant challenges. In this study, we introduce a cutting-edge triboelectric-mechanoluminescent electronic skin (TMES) that exhibits a remarkable response to multiple external stimuli. This advancement is achieved by integrating a mechanoluminescent intermediate layer within a triboelectric nanogenerator (TENG). When pressure is applied to TMES, the maximum detection voltage can reach hundreds of volts and the maximum correlation sensitivity is 11.76 V/N. Moreover, we incorporate luminescence materials into mechanoluminescence layer, and the maximum absolute sensitivity SR can reach 1.41%. The device can not only distinguish between external stimuli such as pressing and bending but also continuously track external mechanical stimuli. A 4 × 4 matrix and motion prediction of 8 different postures were established to further demonstrate the significant advantages of the developed device in spatial detection. The versatility and performance of the TMES hint at its vast potential in areas such as human-computer interaction and wearable electronics, paving the way for more intuitive and dynamic technological interfaces.

The tumor suppressor Parkin exerts anticancer effects through regulating mitochondrial GAPDH activity.

Cancer cells preferentially utilize glycolysis for energy production, and GAPDH is a critical enzyme in glycolysis. Parkin is a tumor suppressor and a key protein involved in mitophagy regulation. However, the tumor suppression mechanism of Parkin has still not been elucidated. In this study, we identified mitochondrial GAPDH as a new substrate of the E3 ubiquitin ligase Parkin, which mediated GAPDH ubiquitination in human cervical cancer. The translocation of GAPDH into mitochondria was driven by the PINK1 kinase, and either PINK1 or GAPDH mutation prevented the accumulation of GAPDH in mitochondria. Parkin caused the ubiquitination of GAPDH at multiple sites (K186, K215, and K219) located within the enzyme-catalyzed binding domain of the GAPDH protein. GAPDH ubiquitination was required for mitophagy, and stimulation of mitophagy suppressed cervical cancer cell growth, indicating that mitophagy serves as a type of cell death. Mechanistically, PHB2 served as a key mediator in GAPDH ubiquitination-induced mitophagy through stabilizing PINK1 protein and GAPDH mutation resulted in the reduced distribution of PHB2 in mitophagic vacuole. In addition, ubiquitination of GAPDH decreased its phosphorylation level and enzyme activity and inhibited the glycolytic pathway in cervical cancer cells. The results of in vivo experiments also showed that the GAPDH mutation increased glycolysis in cervical cancer cells and accelerated tumorigenesis. Thus, we concluded that Parkin may exert its anticancer function by ubiquitinating GAPDH in mitochondria. Taken together, our study further clarified the molecular mechanism of tumor suppression by Parkin through the regulation of energy metabolism, which provides an experimental basis for the development of new drugs for the treatment of human cervical cancer.