P-N Heterojunction formation: Metal Sulfide@Metal Oxide Chemiresistor for ppb H2S Detection from Exhaled Breath and Food Spoilage at Flexible Room Temperature.

The development of a portable, low-cost sensor capable of accurately detecting H2S gas in exhaled human breath at room temperature is highly anticipated in the fields of human health assessment and food spoilage evaluation. However, achieving outstanding gas sensing performance and applicability for flexible room-temperature operation with parts per billion H2S gas sensors still poses technical challenges. To address this issue, this study involves the in situ growth of MoS2 nanosheets on the surface of In2O3 fibers to construct a p-n heterojunction. The In2O3@MoS2-2 sensor exhibits a high response of 460.61 to 50 ppm of H2S gas at room temperature, which is 19.5 times higher than that of the pure In2O3 sensor and 322.1 times higher than that of pure MoS2. The In2O3@MoS2-2 also demonstrates a minimum detection limit of 3 ppb and maintains a stable response to H2S gas even after being bent 50 times at a 60° angle. These exceptional gas sensing properties are attributed to the increase in oxygen vacancies and chemisorbed oxygen on In2O3@MoS2-2 nanofibers as well as the formation of the p-n heterojunction, which modulates the heterojunction barrier. Furthermore, in this study, we successfully applied the In2O3@MoS2-2 sensor for oral disease and detection of food spoilage conditions, thereby providing new design insights for the development of portable exhaled gas sensors and gas sensors for evaluating food spoilage conditions at room temperature.

Mn-based Prussian blue analogues: Multifunctional nanozymes for hydrogen peroxide detection and photothermal therapy of tumors.

Nanozymes have the advantages of simple synthesis, high stability, low cost and easy recycling, and can be applied in many fields including molecular detection, disease diagnosis and cancer therapy. However, most of the current nanozymes suffer from the defects of low catalytic activity and single function, which limits their sensing sensitivity and multifunctional applications. The development of highly active and multifunctional nanozymes is an important way to realize multidisciplinary applications. In this work, Mn-based Prussian blue analogues (Mn-PBA) and their derived double-shelled nanoboxes (DSNBs) are synthesized by co-precipitation method. The nanobox structure of DSNBs formed by etching Mn-PBA with tannic acid endows Mn-PBA DSNBs with better peroxidase-like activity than Mn-PBA. A colorimetric method for the rapid and sensitive determination of H2O2 is developed using Mn-PBA DSNBs-1.5 as a sensor with a detection limit as low as 0.62 µM. Moreover, Mn-PBA DSNBs-2 has excellent photothermal conversion ability, which can be applied to the photothermal therapy of tumors to inhibit the proliferation of tumor cells without damaging other tissues and organs. This study provides a new idea for the rational design of nanozymes and the expansion of their multi-functional applications in various fields.

CeO2/Co heterostructure encapsulated in hollow necklace-like carbon fiber as an advanced host material for high-performance lithium-sulfur batteries.

The shuttle effect of lithium polysulfides (LiPSs) and the sluggish reaction kinetics of LiPSs conversion pose serious challenges to the commercial feasibility of lithium-sulfur (Li-S) batteries. To address these obstacles, herein, we construct CeO2/Co heterostructures in hollow necklace-like carbon fibers (CeO2/Co-CNFs) as the cathode host material for Li-S batteries. The specific surface area of fibers is significantly enhanced by using a template, thereby promoting the utilization efficiency of sulfur. Meanwhile, CeO2/Co-CNFs show strong conductivity, effective adsorption to LiPSs, and robust catalytic activity for LiPSs conversion. As a result, the Li-S battery with CeO2/Co-CNFs displays 961 mAh g-1 at 0.2 C, with an 86 % capacity retention rate after 100 cycles. At 2.0 C current density, the composite cathode maintains an initial discharge capacity of 782 mAh g-1, with a mere 0.044 % capacity loss per cycle. Furthermore, in situations with limited electrolytes, high sulfur loading, and high areal mass loading, the composite cathode can provide a high areal capacity of 6.2 mg cm-2 over 100 cycles. This work provides a useful approach for investigating high-performance Li-S battery cathodes.

CsPbBr3 perovskite quantum dots-based Janus membrane with multifunction of luminescence, magnetism and aeolotropic electroconductivity.

Lead halide perovskite quantum dots (QDs) are promising semiconductors for next-generation photoelectric devices. However, the development of perovskite QDs-based multifunctional materials still needs to be addressed in order to further advance the application of perovskite QDs. Herein, a successful synthesis of Janus microfibers array Janus membrane (JMAJM) with up-down structure and multifunction of luminescence, magnetism and electroconductivity is firstly achieved based on CsPbBr3 QDs through a parallel electrospinning. JMAJM comprises up-down two layers tightly bonded together. The up-layer of JMAJM is luminescence/magnetism Janus microfibers array (L/M-JMAJM) constructed by [CsPbBr3/polymethyl methacrylate (PMMA)]//[CoFe2O4/PMMA] Janus microfibers as building elements. The down-layer of JMAJM is luminescence/electroconductivity Janus microfibers array (L/E-JMAJM) fabricated by [CsPbBr3/PMMA]//[polyaniline (PANI)/PMMA] Janus microfibers as building elements. Two independent microcosmic regions are designed and realized in a Janus microfiber, confining luminescence with magnetic or conductive substances into their respective regions, thus minimizing adverse effects of other dark-colored functional substances on the fluorescence of CsPbBr3 QDs. This peculiar Janus microfiber enables the effective separation and high integration of CsPbBr3 QDs with other functional substances. The up-down structure of JMAJM ensures a high integration of luminescence, magnetism and conductivity. Meanwhile, JMAJM addresses the environmental instability of CsPbBr3 QDs while simultaneously endows perovskite QDs-based materials with additional functions to realize multifunction. Under ultraviolet excitation, fluorescence characteristics of the CsPbBr3 QDs in JMAJM are maintained, exhibiting a vibrant green emission at 517 nm. Meanwhile, JMAJM achieves a maximum saturation magnetization of 20.32 emu·g-1, high conductance of 10-2 S and aeolotropic electroconductivity degree of 107. The combination of micro-partition with macro-partition in JMAJM receives superior concurrent luminescence-magnetic-conductive multifunction. This work provides a novel idea and strategy for advancing perovskite QDs-based multifunctional materials.

Novel green/red oxyfluoride phosphors with excellent optical properties for near-UV excited white light emitting diode.

Novel eye-sensitive Ba3Nb2O2F12(H2O)2:Tb3+ green and Ba3Nb2O2F12(H2O)2:Mn4+ red oxyfluoride phosphors with extremely strong absorption in the UV region were designed and synthesized by simple co-precipitation strategy. Particularly, Tb3+ ions were doped in this matrix for the first time, which greatly improves their absorption efficiency in the near ultraviolet region (367 nm) and emits sharp green light (544 nm). In addition, the Ba3Nb2O2F12(H2O)2:Mn4+ red phosphors have strong zero phonon line (ZPL) emission at 625 nm, which is conducive to improving the sensitivity of human eye and color purity. Meanwhile, the optical properties of the red phosphor are significantly enhanced via doping K+ cations as charge compensators. Crystal field environment and nephelauxetic effect of the as-prepared phosphors before and after K+ cation doping were systematically analyzed. Moreover, these synthesized red/green phosphors have good thermal stability and moisture resistance. Remarkably, the as-prepared Ba3Nb2O2F12(H2O)2:5%Mn4+ or K0.9Ba2.1Nb2O2F12(H2O)2:5%Mn4+ red phosphors can be directly mixed with the as-synthesized Ba3Nb2O2F12(H2O)2:13%Tb3+ green phosphor coating on 365 nm near-ultraviolet LED chip to package WLED devices with excellent electroluminescence performance. These findings are conducive to opening an avenue for screening the unique structure of optical materials.

Self-supporting multi-channel Janus carbon fibers: A new strategy to achieve an efficient bifunctional electrocatalyst for overall water splitting.

A new type of self-supporting multi-channel Janus carbon fibers with efficient water splitting has been successfully manufactured using a specially designed parallel spinneret through electrospinning technology and subsequent carbonization technique. Every single Janus fiber composes of a half side of Mo2C and the other half side of Ni components as Mo2C, Ni embedded in N-doped multi-channel Janus carbon fibers ([Mo2C/C]//[Ni/C]-NMCFs) for overall water splitting. Under optimized condition, the hydrogen evolution reaction overpotential of [Mo2C/C]//[Ni/C]-NMCFs (62 mV) is just 24 mV higher than 20 wt% Pt/C (38 mV) at a current density of 10 mA cm-2. Furthermore, it achieves current density of 10 mA cm-2 to require an overpotential of 324 mV for oxygen evolution reaction. Additionally, the cell assembled by the identical [Mo2C/C]//[Ni/C]-NMCFs catalyst as both the cathode and anode needs only 1.607 V at a current density of 10 mA cm-2, which is only 0.022 V higher than that of Pt/C-IrO2 electrodes. Moreover, [Mo2C/C]//[Ni/C]-NMCFs catalyst also exhibits a long-term stability. The synergistic effect and unique heterostructure of Mo2C and Ni enhance the catalytic activity.

Femtosecond Laser Combined with Hydrothermal Method to Construct Three-Dimensional Spatially Distributed Wurtzite ZnO Micro/Nanostructures to Enhance Photocatalytic Properties.

Conventional approaches employing nanopowder particles or deposition photocatalytic nanofilm materials encounter challenges such as performance instability, susceptibility to detachment, and recycling complications in practical photocatalytic scenarios. In this study, a novel fabrication strategy is proposed that uses femtosecond laser direct writing of self-sourced metal to prepare a self-supporting microstructure substrate and combines the hydrothermal method to construct a three-dimensional spatially distributed metal oxide micro/nanostructure. The obtained wurtzite ZnO micro/nanostructure has excellent wetting properties while obtaining a larger specific surface area and can achieve effective adsorption of methyl orange molecules. Moreover, the tight integration of ZnO with the surface interface of the self-sourced metal microstructure substrate will facilitate efficient charge transfer. Simultaneously, it improves the efficiency of light utilization (absorption) and the number of active sites in the photocatalytic process, ultimately leading to excellent photodegradation stability. This result provides an innovative technology solution for achieving efficient semiconductor surface-interface photocatalytic performance and stability.

Facilely Direct Construction, White-Light Emission, and Color-Adjustable Luminescence of LaF3 :Pr3+ @SiO2 Yolk-Shell Nanospheres with Moisture Resistance.

Poor water stability and single luminous color are the major drawbacks of the most phosphors reported. Therefore, it is important to realize multicolor luminescence in a phosphor with single host and single activator as well as moisture resistance. LaF3 :Pr3+ @SiO2 yolk-shell nanospheres are facilely obtained by a designing new technology of a simple and cost-effective electrospray ionization combined with a dicrucible fluorating technique without using protective gas. In addition, tunable photoluminescence, especially white-light emission, is successfully obtained in LaF3 :Pr3+ @SiO2 yolk-shell nanospheres by adjusting Pr3+ ion concentrations, and the luminescence mechanism of Pr3+ ion is advanced. Compared with the counterpart LaF3 :Pr3+ nanospheres, the water stability of LaF3 :Pr3+ @SiO2 yolk-shell nanospheres is improved by 15% after immersion in water for 72 h, and the fluorescence intensity can be maintained at 86% of the initial intensity. Furthermore, by treating the yolk-shell nanospheres with hydrofluoric acid, it is not only demonstrated that the shell-layer is SiO2 but also core-LaF3 :Pr3+ nanospheres are obtained. Particularly, only fluorination procedure among the halogenation can produce such special yolk-shell nanospheres, the formation mechanism of yolk-shell nanospheres is proposed detailedly based on the sound experiments and a corresponding new technology is built. These findings broaden practical applications of LaF3 :Pr3+ @SiO2 yolk-shell nanospheres.

Dual-Confinement Effect of Nanocages@Nanotubes Suppresses Polysulfide Shuttle Effect for High-Performance Lithium-Sulfur Batteries.

The shuttle effect of lithium polysulfides (LiPSs) severely hinders the development and commercialization of lithium-sulfur batteries, and the design of high-conductive carbon fiber-host material has become a key solution to suppress the shuttle effect. In this work, a unique Co/CoN-carbon nanocages@TiO2-carbon nanotubes structure (NC@TiO2-CNTs) is constructed using an electrospinning and nitriding process. Lithium-sulfur batteries using NC@TiO2-CNTs as cathode host materials exhibit high sulfur utilization (1527 mAh g-1 at 0.2 C) and can still maintain a discharge capacity of 663 mAh g-1 at a high current density of 5 C, and the capacity loss is only 0.056% per cycle during 500 cycles at 1 C. It is worth noting that even under extreme conditions (sulfur-loading = 90%, surface-loading = 5.0 mg cm-2 (S), and E/S = 6.63 µL mg-1), the lithium-sulfur batteries can still provide a reversible capacity of 4 mAh cm-2. Throughdensity functional theory calculations, it has been found that the Co/CoN heterostructures can adsorb and catalyze LiPSs conversion effectively. Simultaneously, the TiO2 can adsorb LiPSs and transfer Li+ selectively, achieving dual confinement for the shuttle effect of LiPSs (nanocages and nanotubes). The new findings provide a new performance enhancement strategy for the commercialization of lithium-sulfur batteries.

Optical enhancement of highly efficient organic-inorganic oxyfluoride red phosphors via the cation co-doping strategy.

Herein, a new organic cationic matrix [N(CH3)4]3MoO3F3 suitable for Mn4+ doping was constructed. Due to the large steric hindrance of N[CH3]4+ (TMA), charge compensation defects can be effectively prevented in the heterovalent Mn4+-doping process, and a high IQE (91.05%) was obtained. Through the cation co-doping strategy, Mg2+/Zn2+/Li+ cations were introduced into the Mo6+ cationic site, which improved the crystallinity of the matrix and reduced energy losses, so as to improve luminescence intensity, QE, thermal stability, water stability and other spectral properties. Meanwhile, [N(CH3)4]2TiF6:Mn4+ phosphors with the same TMA organic cation and equivalent Mn4+ doping were synthesized for comparison, and the effects of the Mg2+ cation co-doping strategy on the spectral properties of phosphors with different matrix types (fluoride/oxyfluoride) and substitution types (equivalent/non-equivalent) were analyzed. These findings provide the basis for the preparation of new luminescent materials. Furthermore, according to the optical properties exhibited by these phosphors, they are packaged into WLED devices with excellent photoelectric properties, which are suitable for indoor lighting and display fields.

Construction of a Z-scheme heterojunction bifunctional photocatalyst with Ag-modified AgBr embedded in ß-Bi2O3 flowers.

ß-Bi2O3 demonstrates excellent photocatalytic activity under visible light, but it has a very high photogenerated e--h+ recombination rate and quite low quantum efficiency. AgBr also shows excellent catalytic activity but Ag+ is easily reduced to Ag under light radiation, which limits its application in the photocatalysis field, and there are few reports about the application of AgBr in photocatalysis. In this study, the spherical flower-like porous ß-Bi2O3 matrix was first obtained, and then the spherical-like AgBr was embedded between the petals of the flower-like structure to avoid direct light radiation. The only light through the pores on the ß-Bi2O3 petals could be transmitted onto the surfaces of AgBr particles to form a nanometer point light source, which photo-reduced Ag+ on the surface of the AgBr nanospheres to construct the Ag-modified AgBr/ß-Bi2O3 embedded composite and a typical Z-scheme heterojunction was constructed. Under this bifunctional photocatalyst and visible light, the RhB degradation rate reached 99.85% in 30 min, and the photolysis water hydrogen production rate reached 6.288 mmol g-1 h-1. This work is as an effective method for not only the preparation of the embedded structure, quantum dot modification and flower-like morphology but also for the construction of Z-scheme heterostructures.

Electrospun green-emitting La2O2CO3:Tb3+ nanofibers and La2O2CO3:Tb3+/Eu3+ nanofibers with white-light emission and color-tuned photoluminescence.

Color-tuned luminescence and white-light emission materials have attracted much attention owing to their broad application prospects. Generally, Tb3+ and Eu3+ co-doped phosphors have color-tuned luminescence, but white-light emission is rarely achieved. In this work, color-tunable photoluminescence and white light emission are achieved in Tb3+ and Tb3+/Eu3+ doped monoclinic-phase La2O2CO3 one-dimensional (1D) nanofibers synthesized by electrospinning united with succedent strictly controlling calcination procedure. The prepared samples own excellent fibrous morphology. La2O2CO3:Tb3+ nanofibers are the superior green-emitting phosphors. To obtain 1D nanomaterials with color-tunable fluorescence, particularly those with white-light emission, Eu3+ ions are further selected and doped into La2O2CO3:Tb3+ nanofibers to obtain La2O2CO3:Tb3+/Eu3+ 1D nanofibers. The major emission peaks of La2O2CO3:Tb3+/Eu3+ nanofibers at 487, 543, 596 and 616 nm are attributed to 5D4→7F6 (Tb3+), 5D4→7F5 (Tb3+), 5D0→7F1 (Eu3+) and 5D0→7F2 (Eu3+) energy levels transitions under 250-nm (for Tb3+ doping) and 274-nm (for Eu3+ doping) UV light excitation, respectively. At different wavelengths excitation, La2O2CO3:Tb3+/Eu3+ nanofibers with excellent stability achieve color-tuned fluorescence and white-light emission with the help of energy transfer from Tb3+ to Eu3+ and tuning the doping concentration of Eu3+ ions. Formative mechanism and fabrication technique of La2O2CO3:Tb3+/Eu3+ nanofibers are advanced. The design concept and manufacturing technique developed in this work may offer fresh insights for synthesizing other 1D nanofibers doped with rare earth ions to tune emitting fluorescent colors.

Pseudo-tricolor typed nanobelts and arrays simultaneously endowed with conductive anisotropy, magnetism and white fluorescence.

A novel [uniaxial needle]//[coaxial needle]//[uniaxial needle] parallel spinneret is first innovatively designed and manufactured by inserting a coaxial needle into the middle of a bi-axial parallel needle, and the corresponding spinning device is established. With the aid of the distinctive-structured spinneret and the spinning device, a novel and brand-new flexible one-dimensional nanobelt//coaxial nanobelt//nanobelt tri-strand parallel nanobelt, very much like a tricolor flag and named a pseudo-tricolor typed nanobelt, is successfully prepared by electrospinning technology for the first time. Microscopically, partition of four independent domains in the pseudo-tricolor typed nanobelt is realized, and such a partitioned structure can assemble various functions and helps reduce detrimental interactions among various functions to acquire excellent poly-functions of multifunctional nanomaterials. As a case study, {anthracene/Eu(2-thenoyltrifluoroacetone)3(triphenylphosphine oxide)2 [Eu(TTA)3(TPPO)2]/polymethylmethacrylate (PMMA)}//{[CoFe2O4/PMMA]@[polyaniline (PANI)/PMMA]}//{coumarin-6/PMMA} pseudo-tricolor typed nanobelts and arrays (abbreviated as [B + R]//[M@C]//[G] PNA) are designed and constructed via electrospinning. Each pseudo-tricolor typed nanobelt is composed of left and right sides of blue and red fluorescent [anthracene/Eu(TTA)3(TPPO)2/PMMA] nanobelts and green fluorescent [coumarin-6/PMMA] nanobelts, respectively, and the middle of the [CoFe2O4/PMMA]@[PANI/PMMA] coaxial nanobelt with magnetic-conductive bifunctionality using the CoFe2O4/PMMA nanobelt as the core and PANI/PMMA as the shell. Luminescence-magnetic-conductive polyfunctionalities are highly integrated but also mutually separated in the pseudo-tricolor typed nanobelt, and thus, both segregation and integration of the functions are actualized in the pseudo-tricolor typed nanobelt. A pseudo-tricolor typed nanobelt as the building unit ensures strong fluorescence and high conductive anisotropy of the array. Moreover, energy transfer between dyes is controlled by the special structure of the nanobelt and thus white light emission is realized by the combination of europium complexes with the dyes. The conductive anisotropy and magnetism of the array are tuned by changing the content of PANI and CoFe2O4, respectively. The formation mechanism of the pseudo-tricolor typed nanobelt is proposed, and new techniques for constructing nanobelts and arrays are established. This kind of pseudo-tricolor typed nanobelt with four functional subareas possesses important implications as a building unit to construct other polyfunctional nanostructures. More importantly, the design philosophy and the construction techniques for the novel pseudo-tricolor typed nanobelt and array afford some guidance for the development of other multifunctional materials.

Tri-functional aerogel photocatalyst with an S-scheme heterojunction for the efficient removal of dyes and antibiotic and hydrogen generation.

A novel three-dimensional (3D) S-scheme S-gC3N4/TiO2/SiO2/PAN aerogel heterojunction photocatalyst (denoted as S-gTAHP) is rationally devised and manufactured by combining electrospinning, calcination, hydrothermal and freeze-drying techniques. The synthesized S-gC3N4 molecule is different from traditional g-C3N4, which has a small molecular structure similar to melamine. S-gC3N4 is embedded in the interwoven network structure of TiO2/PAN short fibers, and the catalytic system of the S-scheme heterojunction is formed with SiO2 as a crosslinking agent. S-gTAHP achieves perfect tri-functional photocatalytic capability, including remarkable hydrogen release capacity (806.7 µmol∙h-1∙g-1), efficient removal of three colored dyes with removal efficiencies up to 99.43% (MB, 15 min), 96.13% (RhB, 30 min) and 91.32% (MO, 40 min), and a degradation rate of the colorless antibiotic TCH reaching 84.20% in 40 min driven by simulated sunlight. Meanwhile, the effects of pH values and concentrations of contaminant solutions on the removal rates are explored, and the S-scheme mechanism of S-gTAHP strengthening photocatalytic activity is elucidated. The apparently heightened photocatalytic activities of S-gTAHP can be ascribed to the fact that the 3D hierarchical porous structure of the aerogel endows more active centers and enhanced light-harvesting capacity, and the S-scheme heterojunction supplies effective charge migrating channels, thereby affording the carriers with strong redox capability. Furthermore, S-gTAHP holds prominent reusability and is light weight. Hence, efficient and recyclable 3D aerogel photocatalysts with S-scheme heterojunctions have broad application prospects in practical sewage treatment and energy conversion fields.

Distinctive Sandwich-Type Composite Film and Deuterogenic Three-Dimensional Triwall Tubes Affording Concurrent Aeolotropic Conduction, Magnetism, and Up-/Down-Conversion Luminescence.

Compared to single functional materials, multifunctional materials with electrical conduction, magnetism, and luminescence are more attractive and promising, so it has become an important subject. A distinctive sandwich-type composite film (STCF) with dual-color up- and down-conversion luminescence, magnetism, and aeolotropic conduction is prepared by layer-by-layer electrospinning technology. Macroscopically, STCF is assembled by three tightly bonded layers, including a [polypyrrole (PPy)/poly(methyl methacrylate) (PMMA)]//[NaYF4:Yb3+, Er3+/PMMA] Janus nanobelt array layer as the first layer, a CoFe2O4/polyacrylonitrile (PAN) nanofiber nonarray layer as the second layer, and a Na2GeF6:Mn4+/polyvinylpyrrolidone (PVP) nanofiber nonarray layer as the third layer. This unique macropartition effectually confines conductive aeolotropy, magnetism, and luminescence in different layers. Microscopically, a Janus nanobelt is used as a construction unit to restrict the luminescent and conductive materials to their microregions, thus achieving highly conductive aeolotropy and green luminescence. The high integration of the micro-subarea and macro-subarea in the STCF can efficaciously avoid the mutual disadvantageous effects among different materials to obtain splendid polyfunctional performance. The conductive anisotropy and magnetism of the STCF can be adjusted by changing the contents of PPy and CoFe2O4. When the PPy content reaches 70%, the conductance ratio in the conductive direction to insulative direction is 108. The 2D STCF can be crimped by four different methods, and the 3D TWTs have the same excellent polyfunctional performances as 2D STCF. This unique design idea and construction technology can be applied to the preparation of other multifunctional materials to avoid harmful interference among various functions.

Designed formation of Prussian Blue/CuS Janus nanostructure with enhanced NIR-I and NIR-II dual window response for tumor thermotherapy.

Designing photothermal transducing agents (PTAs) with enhanced photothermal conversion efficiency (PCE) holds essential importance for photothermal tumor eradication applications. Currently, it is an effective way to improve the photothermal efficiency by designing the energy level transition leading to the enhancement of UV absorption. To address the challenge, we develop novel Prussian blue@polyacrylic acid/copper sulfide Janus nanoparticles (PB@PAA/CuS JNPs) via selective coating of PAA nano-hemisphere on one of the surfaces of PB NPs followed by the further formation of CuS on the PAA template. The experiments show that the energy level transition occurs between Janus structure. Besides, it offers enhanced absorption over NIR-I and NIR-II dual windows. The muscle tissue penetration studies suggest that the PB@PAA/CuS JNPs have deeper tissue penetration in the 1064 nm laser irradiation group, indicating their potential for treating deep-tissue-seated tumors. In a word, the unique PB@PAA/CuS JNPs show an enhanced tumor inhibitory effect over the NIR-I and NIR-II dual windows, which will open up new opportunities for improving PTT efficiency by the rational nanostructural design of PTAs.

Two steps synthesis of plum-shaped C@Ni/MnO nanofiber heterostructures for trapping and catalyzing polysulfides in lithium-sulfur batteries.

Both spherical MnO as adsorbent and Ni nanoparticles as catalyzer, with highly exposed contact surface area in the carbon nanofibers, are successfully synthesized via electrospinning technology combined with carbothermal reduction. Compared with typical electrospun carbon nanofiber composites, the as-prepared C@Ni/MnO composite fibers as interlayer enable MnO and Ni to contact fully with polysulfides rather than provide local contact surface. With the sulfur loading of 1.6 mg cm-2 and the approximately 0.1 g composite fibers as interlayer, the cathode shows initial capacity of 687.36 mAh g-1 at 0.5C and superior capacity retention of 70%. This simple technical route leads a way to prepare nanoparticles with highly exposed contact surfaces partially embedded in the carbon nanofibers, which can be applied in electrocatalysis.

"Off-On" typed upconversion fluorescence resonance energy transfer probe for the determination of Cu2+ in tap water.

Detection of copper plays a prominent role in the environmental protection and human health. Herein, we firstly design and construct an "off-on" upconversion fluorescence resonance energy transfer (UFRET) probe with low toxicity for the Cu2+ determination by using NaYF4: Yb3+, Er3+ upconversion nanoparticles (UCNPs) and Au NPs. UCNPs with positive charge and Au NPs with negative charge are respectively employed as the donor and acceptor, and bound together to form UFRET probe. The upconversion fluorescence quenching of UCNPs occurs by Au NPs through FRET (defined as "off" state). When Cu2+ exists in samples, Cu2+ reacts with 4-mercaptobenzoic acid (4-MBA) capped on the surface of Au NPs to make Au NPs detach from UCNPs, leading to the termination of FRET and the recovery of upconversion fluorescence (defined as "on" state). "Off-on" typed UFRET probe has excellent sensing performances, including linear range of 0.02-1 µM Cu2+ concentration, the limit of detection of 18.2 nM, high selectivity to Cu2+ and good recovery. The probe has been successfully used to determine Cu2+ in spiked tap water with satisfactory results. The probe will provide theoretical and technical support for the design of new sensitive heavy metal ion detection probe.

A fluorescent triboelectric nanogenerator manufactured with a flexible janus nanobelt array concurrently acting as a charge-generating layer and charge-trapping layer.

Triboelectric nanogenerators (TENGs) have opened a new direction in the field of flexible devices. Here, a fluorescent TENG-JNA constructed with a flexible Janus nanobelt array (JNA) and PVDF/PVP nanofibers membrane by electro-spinning is reported for the first time. The building unit of JNA is the [PANI/CNTs/PMMA]//[Tb(BA)3phen/PMMA] Janus nanobelts, which demonstrate green fluorescence and electrical conduction bi-function, where two independent partitions are microscopically realized in the Janus nanobelts. In TENG-JNA, JNA concurrently gains excellent charge-trapping ability and charge-generating capability by optimizing the PANI content; therefore, JNA serves as both a charge-generating layer and charge-trapping layer. The interface between TB(BA)3phen and PMMA, the existence of aromatic ring structures in the PANI main chain and the interface between PANI and PMMA are conducive to trap a large number of triboelectric charges in time to prevent the triboelectric charges from combining with induced charges, which can significantly improve the output performance of TENG-JNA. The maximum output current and voltage of TENG-JNA are 6.20 µA and 155 V, respectively. The introduction of Tb(BA)3phen ensures the strong fluorescence of TENF-JNA, and this fluorescence can be used to judge whether TENF-JNA works normally or is out of order in a dark environment. TENG-JNA possesses other compelling features, such as prominent flexibility, good hydrophobicity, durability and light weight, which provides the premise for TENG-JNA to be used as a flexible device in a wet environment or for warning functions. The Janus nanobelt was firstly used to assemble a TENG, which provides theoretical, material and technical support for the development of new building units of TENGs and paves a pathway for designing and assembling new TENGs.

Moisture-resistant Nb-based fluoride K2NbF7:Mn4+ and oxyfluoride phosphor K3(NbOF5)(HF2):Mn4+: synthesis, improved luminescence performance and application in warm white LEDs.

Herein, high-efficiency Nb-based oxyfluoride K3(NbOF5)(HF2):Mn4+ and fluoride K2NbF7:Mn4+ phosphors were successfully synthesized using different amounts of HF acid solutions by a simple co-precipitation method. XRD, SEM and EDS were used to characterize the crystal structure, morphology and elemental composition of the phosphors. The emission spectra, excitation spectra and luminescence decay curves were used to study the luminescence characteristics of the samples. The thermal stability of the phosphors was tested and the mechanism of temperature quenching was discussed. Meanwhile, the moisture resistance and application of the phosphors were investigated in detail. The results show that the K3(NbOF5)(HF2):Mn4+ phosphor has stronger luminous intensity, lower color temperature, and better moisture resistance compared with the K2NbF7:Mn4+ phosphor. The correlated color temperature (CCT) and color rendering index (CRI) of warm white LEDs can be significantly improved by using the K3(NbOF5)(HF2):Mn4+ (CCT = 3430 K, CRI = 87.3) phosphor as a red light component. So the K3(NbOF5)(HF2):Mn4+ phosphor has broader application prospect in the field of warm white LEDs.