Raman spectroscopy is widely applied for substance identification and compositional analysis, while realizing highly sensitive detection of biochemical molecules depends on the spectral enhancement of the substrates. Photo-induced enhanced Raman spectroscopy (PIERS) can significantly enhance the spectral intensity, but the rapid signal decay and short relaxation time limit its wide application. Herein, theoretical analysis and experimental data reveal the synergistic effect of the semiconductor heterojunction nanomaterials in a core-shell structure for the sensitive and stable photoelectric response with spectral enhancement. The ZnO/TiO2/Ag core-shell heterojunction nanowire array with the optimal composition exhibits a PIERS enhancement factor of up to 47 times, approaching the highest reported value to date, and an extraordinarily long relaxation time of over 84 days, which is far superior to those of other material substrates. These unparalleled characteristics provide a reliable, rapid, and convenient technique for the detection of low-concentration biochemical substances.

Ultrathin flexible electronics are of great interest for next-generation wearable and biointegrated systems requiring high mechanical compliance and conformability. In this letter, carbon nanotube thin-film transistors (CNT TFTs) fabricated on an ultrathin polyimide (PI) substrate with a thickness of similar to 80 nm are demonstrated, resulting in a total device thickness of only 109.16 +/- 3.33 nm. The ultrathin substrate is realized through an optimized solution-based process using diluted PI precursors and controlled thermal curing, yielding excellent uniformity with a root-mean-square surface roughness of 391.8 pm. The resulting CNT TFTs exhibit stable electrical characteristics, with a carrier mobility of 16.02 +/- 1.30 cm(2)V(-1) s(-1) and an on/off ratio of similar to 10(5). Bending tests under different radii and cyclic deformation show that the devices maintain their electrical performance under mechanical stress. In addition, the ultrathin devices exhibit excellent conformability to curved and irregular surfaces, such as human fingertips. These results provide a feasible route toward ultraconformable flexible electronics for wearable and biointegrated applications.

Copper mesh with special wettability has attracted enormous attention in the field of oil/water separation, and the construction of Cu(OH)2 nanostructures on the surface of copper mesh is an effective way to obtain such kind of functional material. However, the poor chemical stability of Cu(OH)2 limits its wide use in the field of oil/water separation. In this paper, Poly (ionic liquid) (PIL) was proposed as protective layer for Cu(OH)2, aiming to afford highly stable and performant separating material. Initially, the PIL was prepared by free radical polymerization of ionic liquid monomer 3-ethyl-1-vinylimidazolium bromide, and then was coated on the Cu@Cu(OH)2 filter material, which was prepared by depositing super-hydrophilic Cu(OH)2 nanoneedles on copper mesh. The structures of Cu@Cu(OH)2 and Cu@Cu(OH)2-PIL before and after immersion in acidic, alkaline, and salty solutions were analyzed by XRD, SEM, XPS, and etc. It was found that the immersion of Cu@Cu(OH)2 in NaOH and NaCl solutions collapsed the Cu(OH)2 layer seriously and that in HCl solution caused the complete reaction between the Cu(OH)2 layer and HCl, thereby depriving the ability of oil/water separation. However, the PIL-coated Cu@Cu(OH)2-PIL still retains complete Cu(OH)2 nanoneedles layer after immersion in NaOH and NaCl solutions, and also partially remains some Cu(OH)2 after immersion in HCl solution. The performance test suggests that the prepared Cu@Cu(OH)2-PIL filter material not only can separate oil/water mixtures in wastewater environment, but also can separate organic solvents (hexadecane/methanol mixtures) with different polarity. Therefore, the novel designed filter material shows wider promise for application.

Plasmonic coupling of the nanoparticles plays a key role in the performance, but most previous studies have focused on the isolated nanoparticles, nanoparticle dimers with round surface or nanoparticle arrays. Here plasmonic properties of gold nanosheet monomers and dimers in rectangular structure are investigated. The plasmon resonance of the monomers is found to be primarily controlled by the light polarization, rather than the incident orientation. The strongest resonance is achieved when the polarization aligns with the long axis of the nanosheet. For the dimers, the strong coupling leads to the appearance of multistage plasmonic peaks and significant amplification of the resonant bands. Structural changes in the dimers induce the band shift and intensity variation. The optimal dimer displays a strong plasmonic coupling with a maximum electric field enhancement and a tremendous sensitivity of 748.3 nm/RIU, which provides valuable insights for the design and applications of noble metal nanostructures.

Semiconductor photocatalysts have been widely applied in the environmental remediation, but the sole light excitation and fast charge recombination restrict their performance seriously. The introduction of piezoelectricity with the construction of semiconductor heterostructures would significantly improve the photocatalytic efficiency. Here ZnO/Ag2S heterogeneous nanowire arrays were constructed on the porous nickel foams. By harnessing the mechanical stress provided by fluid vortex on the catalyst, the photoluminescence intensity decreases to 78 % of its original value, the photocurrent density increases from 1.10 mA/cm2 to 1.35 mA/cm2 at 300 rpm, and the degradation efficiency of rhodamine B improves from 58.6 % to 96.6 % with perfect repeatability and stability. The superoxide radicals and hydroxyl radicals are found to dominate in the pollutant degradation, and the radical number is enormously augmented by the flow-induced piezoelectric field. Theoretical analysis reveals significant contribution of the piezoelectricity on the photoresponse, energy band alignment and photocatalytic performance of the semiconductor heterostructure, which would promote practical application of the piezo-photocatalysis in environmental remediation.

Exploiting metal chalcogenide-based photocatalysts has fascinated researchers as a source of green hydrogen (H2) energy. Herein, we have designed a novel selenium-enriched NiSe1+x/ZIS (NiSexZ) photocatalytic system via a two-step hydrothermal and facile photo-deposition method. It was fascinating to conclude here that the NiSexZ photocatalytic system showed boosted H2 evolution results in comparison with other sulphur-enriched NiS1+x/ ZIS (NiSxZ) and tellurium-enriched NiTe1+x/ZIS (NiTexZ). The optimized NiSe0.5Z composite exhibited a photocatalytic H2 evolution of 3.24 mmol g-1 h-1, a 9.8-fold increase over pure ZIS and it demonstrated an apparent quantum efficiency (AQE) of 2.06 % via 420 nm filter. Moreover, sulphur (S), selenium (Se), and tellurium (Te) synergistic active sites were exposed to promote H2 evolution reaction in this work. Given the significant advancements and commendable performance exhibited by the Se-Hads across the week bond, it is extremely probable that the NiSe1+x cocatalyst holds immense potential for the development of sophisticated photocatalytic materials.

Proton exchange membrane water electrolysis (PEMWE) is a key technology for sustainable hydrogen production; however, its efficiency is limited by the sluggish kinetics and high overpotential of the anodic oxygen evolution reaction (OER). Although RuO2 offers a cost-effective alternative to scarce IrO2-based catalysts, its application is impeded by a fundamental trade-off between activity and stability under acidic conditions. Herein, we incorporate Hafnium (Hf) into the RuO2 lattice to modulate the Ru oxidation state and oxygen vacancy concentration. The introduction of Hf suppresses Ru overoxidation, while controlled generation of oxygen vacancies minimizes lattice oxygen participation. The optimized Hf0.1Ru0.9O2 catalyst exhibits a low overpotential of 187 mV at 10 mAu00B7cmu22122 and outstanding durability, maintaining performance for 1500 h in 0.5 M H2SO4. Notably, a practical PEMWE device employing this catalyst achieves stable operation for over 600 h at 500 mAu00B7cmu22122. A combination of in-situ differential electrochemical mass spectrometry (DEMS) and operando attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) reveal that Hf0.1Ru0.9O2 facilitates oxygen evolution primarily through a multiple-pathway mechanism dominated by the adsorbate evolution mechanism (AEM) and the oxide pathway mechanism (OPM), with effectively suppressed lattice oxygen-mediated mechanism (LOM). These findings establish a new design principle for the development of durable acidic OER electrocatalysts.

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Metal halide perovskite quantum dots (PQDs) are promising for next-generation optical displays, yet challenges persist in achieving pure-red emission (620-640 nm) due to a lack of effective ligand exchange methods for enhancing charge carrier transfer and stabilizing the PQDs structure/size during post-treatment. Herein, we report spectrally stable and efficient pure-red light-emitting diodes (LEDs) realized through sequential ligand post-treatment of all-inorganic CsPbI3 PQDs. The as-synthesized CsPbI3 PQDs (similar to 4 nm) undergo sequential purification steps, employing trioctylphosphine oxide (TOPO) and guanidinium iodide (GUAI) as ligands. This approach preserves the size and structure of the CsPbI3 PQDs after two purification washes, improving the optoelectronic properties of CsPbI3 PQD films and enables a stable electroluminescent emission centered at 640 nm with an external quantum efficiency (EQE) peaking near 15%. Our sequential ligand post-treatment successfully prevents the aggregation and coarsening of PQDs, presenting a novel approach toward enhancing the stability and efficiency of PQD-based LED technologies.

Roxarsone (ROX) is the main form of arsenic pollution in the world, and developing effective methods for its elimination is beneficial to human health and the ecological environment. Herein, we report glutaraldehyde cross-linked chitosan-encapsulated CoCe-LDH (layered double hydroxides) as an outstanding catalyst for the advanced oxidation of ROX and the efficient adsorption of inorganic arsenic. 100% of ROX and more than 98.5% of As(III)/As(V) were eliminated, and over 99.3% of remaining inorganic arsenic was oxidized to low-toxicity As(V) in the peroxymonosulfate (PMS) activation system, and some specific properties of LDH are considered the main reasons. The hierarchical anion exchange has been confirmed to be beneficial for constructing a high-concentration PMS interlayer microenvironment. The unique reverse electron transfer process induced 100% selective production of singlet oxygen. This work not only develops an advanced ROX removal method but also provides a new understanding of the LDH-based advanced oxidation process.

AbstractMetal halide perovskite nanocrystals (PNCs) hold great promise for light‐emitting diodes (LEDs) due to their high photoluminescence quantum yields (PLQY), tunable colors, and low‐cost solution processability. However, their electroluminescence efficiencies are currently limited by the small size of the PNCs and the weak binding between ligands and PNCs. The small size makes PNCs sensitive to environmental factors due to their large specific surface area, leading to a loss of PLQY during post‐treatment. Additionally, the weak binding between ligands and PNCs causes the ligands to detach during post‐treatment, further reducing PLQY. To address these challenges, an in situ ligand‐capped synthesis method is introduced for PNCs, replacing the aliphatic solvent octadecene (ODE) with trioctylphosphine (TOP). The presence of TOP increases the concentration of monomers, accelerating nucleation and crystal growth, enabling the production of cubic PNCs ranging from 8 nm to over 28 nm. Moreover, TOP acts as a ligand to resurface PNCs, enhancing their stability and maintaining high PLQY after post‐treatment. As a result, by utilizing these larger PNCs, a high maximum external quantum efficiency (EQE) of 21.23% in LEDs is achieved. This method provides a significant advancement in the development of high‐performance PNC‐based LEDs.

Metal-organic frameworks (MOFs) is easy to agglomerate at high temperature, resulting in the rapid collapse of the MOFs structure and the aggregation of metal sites. In this paper, Al2O3 is used as the support material to support the in-situ synthesis of Ni-MOF on the surface, and the metal Ni nanoparticles are successfully fixed on the Al2O3. The results showed that both Ni/Ni-MOF-300 and Ni/NA-MOF-300 catalysts reduced at 300 ℃ have good hydrogenation activity of benzene, and Ni/Ni-MOF-450 catalysts reduced at 450 ℃ formed huge Ni aggregates, which significantly reduced the hydrogenation activity of benzene. However, Ni/NA-MOF-450 catalyst reduced at 450 ℃ can effectively resist the metal Ni agglomeration caused by the collapse of MOFs structure at high temperature, and has better hydrogenation activity of benzene.

Hydrogels are hydrophilic 3-dimensional networks characterized by the retention of a large amount of water. Because of their water component, hydrogels are a promising method for targeted drug delivery. The water component, or “free volume”, is a potential vehicle for protein drugs. A particularly intriguing hydrogel is pectin. In addition to a generous free volume, pectin has structural characteristics that facilitate hydrogel binding to the glycocalyceal surface of visceral organs. To test drug function and pectin integrity after loading, we compared pectin films from four distinct plant sources: lemon, potato, soybean, and sugar beet. The pectin films were tested for their micromechanical properties and intrinsic antibacterial activity. Lemon pectin films demonstrated the greatest cohesion at 30% water content. Moreover, modest growth inhibition was observed with lemon pectin (p < 0.05). No effective inhibition was observed with soybean, potato, or sugar beet films (p > 0.05). In contrast, lemon pectin films embedded with carbenicillin, chloramphenicol, or kanamycin demonstrated significant bacterial growth inhibition (p < 0.05). The antibacterial activity was similar when the antibiotics were embedded in inert filter disks or pectin disks (p > 0.05). We conclude that lemon pectin films represent a promising structural platform for antibacterial drug delivery.

The BiOIO3/BiOCl heterojunctions with different dominated facet, BiOIO3/{110}BiOCl and BiOIO3/{001} BiOCl, were prepared through facile solvothermal/hydrothermal methods with ethylene glycol/deionized water as solvents. As. prepared BiOIO3/BiOCl photocatalysts were characterized by X-ray diffraction, scanning electron microscope, energy. dispersive spectroscopy, and UV-Vis diffuse reflectance spectra. The photocatalytic activity of BiOIO3/BiOCl heterojunctions was evaluated by photo-catalytically decomposing rhodamine B and phenol in an aqueous solution under visible light irradiation. The results showed that 25% BiOIO3/{110}BiOCl heterojunctions exhibited the highest photocatalytic efficiency. The degradation of RhB over 25% BiOIO3/{110}BiOCl was 98.7% after 15 min of light irradiation. And 100% phenol can be degraded after irradiation for 150 min. The better photocatalytic performance of BiOIO3/{110}BiOCl may be attributed to the strong absorption of the visible light, the heterojunction structure, and the efficient separation of photo-generated carriers benefiting from the dominated (110) facet of BiOCl. The superoxide radicals (center dot O-2(-)) and holes (h(+)) are the main active species in the photocatalytic pro. cess. Moreover, a reasonable mechanism for enhanced photocatalytic performance was also discussed based on the experimental results.

As the main reaction in both the glucose fuel cells and sensors, glucose oxidation reaction (GOR) is vital to their properties. In this work, we present a highly efficient GOR catalyst with two-dimensional sheet-like structures, which was prepared through one-pot self-assembled process. The as prepared Ni/Ni3C/C3N4 nanosheets with thickness less than 50 nm were composed of many Ni/Ni3C nanoparticles less than 5 nm anchoring on C3N4 sheets. Electrochemical characterizations confirmed that Ni/Ni3C/C3N4 nanosheets have the excellent GOR performance. The glucose fuel cells equipped with Ni/Ni3C/C3N4 nanosheets anodes (599.68 mu W center dot cm(-2)) displayed greater power density than that of Ni, Ni3C, and C3N4 with the maximum power density obtained at 0.41 V. Moreover, the superior non-enzymatic glucose sensing performance was also obtained on Ni/Ni3C/C3N4 nanosheets electrodes, including high sensitivity (395.08 mu A.mM(-2).cm(-2) in range of 0-1000 mu M and 163.64 mu A.mM(-2).cm(-2) in range of 1000 mu M - 12000 mu M), low detection limit (0.33 mu M), good stability and repeatability. The high performance of Ni/Ni3C/C3N4 nanosheets may be due to the fast charge and mass transfer originating from the synergistic effect of Ni/Ni3C and C3N4 nanosheets.

Three types of Co3O4 catalyst, namely Co3O4 nanoparticles (denoted as Co3O4-NPs, ∼12 nm in diameter), Co3O4 nanoparticles encapsulated in mesoporou s SiO2 (denoted as Co3O4@SiO2), and Co3O4 nanoparticles inside microporous SiO2 hollow sub-microspheres (denoted as Co3O4-in-SiO2), were explored to catalyze the combustion of lean methane. It was found that the methane conversion over the three catalysts has the order of Co3O4-NPs ≈ Co3O4@SiO2 > Co3O4-in-SiO2 due to the different catalyst structure. The comparison experiments at high temperatures indicate the Co3O4@SiO2 has a significantly improved anti-sintering performance. Combined with the TEM and BET measurements, the results prove that the presence of the mesoporous SiO2 layer can maintain the catalytical activity and significantly improve the anti-sintering performance of Co3O4@SiO2. In contrast, the microporous SiO2 layer reduces the catalytical activity of Co3O4-in-SiO2 possibly due to its less effective diffusion path of combustion product. Thus, the paper demonstrates the pore size of SiO2 layer and catalyst structure are both crucial for the catalytical activity and stability.

NiO/Fe2O3 modified glass carbon (GCE) electrode was prepared by electrodeposition of NiO nanoparticles on Fe2O3/GCE. The electrochemical characteristics of NiO/Fe2O3/GCE have been examined using cyclic voltammetry. The enhanced electrocatalytic activity of NiO/Fe2O3/GCE modified electrode for nitrite oxidation may be related to the synergistic effect of NiO and Fe2O3 nanoparticles, which may not only modify the electronic structure of the composite materials but also favor the increase of active sites in NiO/Fe2O3 and help to adsorb more active materials. To detect nitrite, the NiO/Fe2O3/GCE modified electrode was employed as an electrochemical sensor. There is a strong linear correlation between concentration and peak current (R = 0.9993) in the 5-500 & mu;M range, and a detection limit of 0.05 & mu;M (S/N = 3) was established. NiO/Fe2O3 sensors have excellent selectivity and stability as well. The sensor performs well analytically in determining nitrite in tap water, indicating that it has the possibility for efficient application in nitrite detection. This simple, low-cost, stable and highly sensitive nitrite electrochemical sensor provides a promising method for the detection of nitrite in practical samples.

Ternary metal oxide nanorods Ni0.5Cu0.5Co2O4 with high activities for glucose oxidation were prepared through a simple hydrothermal process. The as prepared Ni0.5Cu0.5Co2O4 NRs with uniform aspect ratio were composed of many nanoparticles with diameter less than 10 nm Ni0.5Cu0.5Co2O4 NRs modified glassy carbon electrodes displayed highly improved non-enzymatic glucose sensing (NEGS) performance compared to pure phase NiCo2O4 NRs and CuCo2O4 NRs. The sensitivity of Ni0.5Cu0.5Co2O4 NRs for glucose detection in the lower (5-3000 mu M) and higher regional (3000-7000 mu M) is 859.31 mu A mM(-1) cm(-2) and 528.81 mu A.mM(-1).cm(-2), respectively. The limit of detection (LOD) was estimated to be 1.67 mu M (S/N = 3). Moreover, the direct glucose fuel cells (DGFCs) equipped with Ni0.5Cu0.5Co2O4 NRs anode also presented much higher power density (413.7 mu W cm(-2)), which is 2 times higher than that of CuCo2O4 NRs (200.2 mu W cm(-2)) and 4.7 times than NiCo2O4 NRs (87.4 mu W cm(-2)). The improved electrochemical performance of Ni0.5Cu0.5Co2O4 NR may benefit from the highly increased charge transfer, which is due to the incorporation of third metal atoms into the spinel lattice of CuCo2O4 or NiCo2O4. The results suggested that Ni0.5Cu0.5Co2O4 NR may be a promising catalyst for application in both NEGS and DGFCs.

The high activity and reliability of bifunctional oxygen catalysts are imperative for rechargeable metal–air batteries. However, the preparation of bifunctional non–noble metal electrocatalysts with multiple active sites remains a great challenge. Herein, an MOF–derived N–doped C–loaded uniformly dispersed CoO/MoC heterojunction catalyst for high–performance dual function was prepared by a simple “codeposition–pyrolysis” method. Experimental investigations revealed that the formation of the heterojunction can tailor the valence of Co and Mo sites, which impressively modulates the electronic properties of the active sites and promotes the electrocatalytic processes. The optimal catalyst reveals a high–wave half potential (E1/2 = 0.841 V) for ORR and a low overpotential (E10 = 348 mV) for OER. The NCCM–600–based Zn–air battery displays a high peak power density of 133.36 mW cm−2 and a prolonged cycling life of more than 650 h. This work provides avenues for the development of functional materials with enhanced properties in a variety of practical energy applications.