Electrolysis of seawater is an appealing route for the production of green hydrogen without any stress on drinkable freshwater reservoirs, but its large-scale exploitation is harshly limited by the anodic chlorine oxidation reaction (ClOR), resulting in material corrosion and limiting the efficiency and sustainability of this technology. Consequently, active, stable, and eco-friendly electrocatalysts capable of selectively promoting the oxygen evolution reaction (OER), suppressing thus ClOR, are highly demanded for further advancements in the field. In this context, the present work reports for the first time on the fabrication of crystalline manganese ferrite thin films by an original chemical vapor deposition (CVD) route, starting from a mixture of Mn and Fe beta-diketonate diamine adducts acting as single-source precursor for the target systems. Controlled variations of the relative precursor amounts allowed to modulate the structural and compositional characteristics of the resulting materials, with particular regard to the Mn/Fe ratio. Electrochemical tests in real seawater environments yielded, for the best performing system, an outstanding Tafel slope of approximate to 60 mV dec-1, and enabled to rule out hypochlorite generation. These performances, accompanied by an appreciable operational stability, underscore the potential of the present electrocatalysts for renewable energy-related applications.

Surface-enhanced Raman scattering (SERS) has emerged as a powerful analytical technique for trace detection of various molecular species, including emerging pollutants, but its sensitivity remains critically dependent on the rational design of plasmonic substrates. Metal film over nanospheres (MFoN) represent a particularly versatile platform, exhibiting an architecture that allows tuning of the localized surface plasmon resonances, thus enabling optimized SERS enhancement, but also limiting hot spot density and distribution. Here, we introduce quasi-3D sculpted gold films over nanospheres (AuFoN) that overcome this limitation through a simple yet innovative fabrication strategy. By assembling polystyrene nanospheres onto polystyrene substrates followed by their simultaneous plasma etching, we create spatially extended three-dimensional plasmonic architectures with dramatically enhanced hot spot distributions. This low-cost and scalable approach yields large-area substrates (>cm2) with excellent reproducibility and morphological control. Comprehensive characterization via scanning electron microscopy, optical spectroscopy, and wavelength-scanned NIR-SERS using benzenethiol monolayers reveals superior SERS enhancement compared to that of conventional AuFoN. We demonstrate the efficiency of these quasi-3D substrates through the detection of two environmental pollutants of different origin, propranolol (β-blocker) and thiabendazole (fungicide). Detection limits of 2 × 10−7 M were achieved for thiabendazole falling within concentration ranges relevant for environmental monitoring scenarios. This work positions quasi-3D sculpted AuFoN plasmonic architectures as a promising platform for next-generation SERS-based sensors, combining facile fabrication with enhanced analytical performance, while further validation in complex real-world sample matrices remains an important direction for future work.

Water electrolysis has emerged as a strategically appealing route for the sustainable production of green hydrogen (H2) via the hydrogen evolution reaction (HER), though the sluggish kinetics of the oxygen evolution reaction (OER) remains a bottleneck hindering large-scale practical applications. In this regard, an attractive solution is offered by the integration of the ethanol oxidation reaction (EOR) into hybrid water-splitting systems, favorably reducing anodic overpotentials. Nonetheless, an open challenge is related to the fabrication of eco-friendly and economically viable catalysts free from noble metals, combining efficiency and stability. Herein, we explore nickel-oxide-based nanostructures grown onto porous Ni foam scaffolds by a scalable hydrothermal (HT) approach as EOR electrocatalysts. Material properties arising from modulation of the sole HT growth time are investigated by complementary structural, microscopic, and spectroscopic techniques. Electrochemical tests demonstrate good durability and very attractive EOR performances, mainly influenced by the morphology and the NiOOH surface content of the target systems. Overall, the present work advances an attractive route to transition-metal-based electrocatalysts for efficient alcohol-oxidation-assisted water electrolysis.

Nanoplastics are nowadays a significant subject of interest due to their potential negative impact on human health and environmental quality. Their submicron size necessitates innovative analytical techniques like surface-enhanced Raman scattering (SERS), which proves highly effective in trace molecular detection within the nanometer range. Although SERS technology has advanced significantly, there is a largely unexplored gap between demonstrating the efficiency of SERS substrates with probe molecules and the practical use of these substrates for nanoplastic detection. Therefore, this study explores whether the optimization of a specific SERS substrate towards molecular analytes is also valid for the detection of individual nanoplastics. Since SERS relies on materials with nanoscale features, here we present a new class of nanostructured SERS substrates with different surface morphologies and tuned plasmonic response fabricated by the colloidal lithography technique. In this regard, we first performed the SERS enhancement characterization of the plasmonic substrates functionalized with a molecular analyte (benzenethiol) by wavelength-scanned surface-enhanced Raman scattering measurements in the near-infrared spectral range. Furthermore, we investigated the SERS performance of the substrates for the detection of individual polystyrene spherical nanoplastic particles and the experimental results were corroborated with finite-difference time-domain (FDTD) analysis. The results indicate that while a SERS substrate optimized for molecular analytes may show excellent efficiency, separate optimization is necessary for efficient detection of individual nanoplastic particles.

Photocatalytic nanomaterials offer promising solutions for conducting chemical transformations under safe, green and sustainable conditions. In particular, the storage of solar energy into chemical bonds is an appealing but challenging goal in the field of artificial photosynthesis. Using water as the source of electrons and protons through the photodriven water oxidation (WO) reaction is at the core of this endeavour. In this work, we disclose photoactive hybrid nanomaterials designed through a dyadic approach. We exploit Co3O4 nanoparticles (NPs) covalently functionalized with a fully organic pentacyclic polyquinoid KuQuinone (KuQ) dye, providing a rare example of a noble metal-free photocatalytic dyadic nanomaterial (hereafter denoted as KuQ3Pn@Co3O4). KuQ3Pn@Co3O4 NPs have been characterized by electron microscopy and optical and core-level spectroscopy studies. When cast onto a SnO2 photoanode, they are active towards WO upon visible light irradiation (400-580 nm) with a faradaic efficiency for O2 evolution of ca. 90%. This work provides a novel contribution to the rational design and mechanistic understanding of hybrid photocatalytic nanomaterials relevant for energy and sustainable synthesis applications.

TiO 2 nanoparticles sensitized with the quinacridone industrial pigment enable the photocatalytic oxidation of glycerol to glyceraldehyde exploiting red light.

Local temperature measurement is crucial for understanding nanoscale thermal transport and developing nanodevices for biomedical, photonic, and optoelectronic applications. The rise of photothermal therapy for cancer treatment has increased the demand for high-resolution nanothermometric techniques capable of non-contact intracellular temperature measurement and modification. Raman spectroscopy meets this need: the ratio of anti-Stokes to Stokes Raman intensities for a specific vibrational mode correlates with local temperature through the Boltzmann distribution. The present study proposes a novel photothermal therapy agent designed to advance the current state of the art while adhering to green chemistry principles, thereby favoring low-temperature synthesis involving limited energy consumption. A key challenge in this field is to achieve close contact between plasmonic nanosystems, which act as nanoheaters, and local temperature sensors. This is achieved by employing silver nanoparticles as a heat release agent, coated with anatase-phase titanium dioxide, as a local temperature sensor. The proposed synthesis, which combines refluxing and subcritical solvothermal treatments, enables direct anatase formation, despite its metastability under standard conditions, thus eliminating the need for a calcination step. Structural characterization through SAED-HRTEM and Raman spectroscopy confirms the successful crystallization of the desired phase. Moreover, the nanothermometry measurements conducted at various wavelengths ultimately demonstrate both the effectiveness of these nanomaterials as thermometric probes, with a relative sensitivity of about 0.24 K-1%, and their capability as local heaters, with a release of a few tens of degrees. This work demonstrates a new synthetic strategy for these nanocomposites, which offers a promising pathway for the optimization of nanosystems in therapeutic applications.

Monosodium urate, calcium pyrophosphate, and basic calcium phosphate crystals are the most common types of crystals found in the joints. Each type of crystal has been associated with the onset of different joint diseases. However, the mechanisms identified for one type of crystal are often generalized to the others; thus, overlooking the specific and distinct molecular and cellular responses activated by each type of crystal. This review describes the similarities and differences of the main molecules and mechanisms underlying the diseases associated with the three different types of crystals. Specifically, current knowledge on crystal properties and formation, on the induction and resolution of inflammation, on mechanisms involved in pain processing and senescence, and on the role of mitochondria and genomic instability are elucidated. A more complete and detailed study of the specific molecular mechanisms induced by different crystals is necessary to advance our understanding of the pathogenesis and to help identify innovative opportunities for prevention and treatment of crystal deposition disease.

Integrated circuits are created by interfacing different materials, semiconductors, and metals, which are appropriately deposited or grown on substrates and layers soldered together. Therefore, the characteristics of starting materials and process temperatures are of great importance, as they can induce residual strains in the final assembly. Identifying and quantifying strain becomes strategically important in optimizing processes to enhance the performance, duration, and reliability of final devices. This work analyzes the thermomechanical local strain of semiconductor materials used to realize LED modules for lighting applications. Gallium Nitride active layers grown on sapphire substrates and Si chips are assembled by soldering with eutectic AuSn on copper substrates and investigated by Raman spectroscopy in a temperature range of −50 to 180 °C. From the Raman mapping of many different samples, it is concluded that one of the leading causes of strain in the GaN layer can be attributed to the differences in the thermal expansion coefficient among the various materials and, above all, among the chip, interconnection material, and substrate. These differences are responsible for forces that slightly bend the chip, causing strain in the GaN layer, which is most compressed in the central region of the chip and slightly stretched in the outer areas.

Nd3+,Y3+ codoped CaF2 nanoparticles (NPs) have been synthesized by a microwave-assisted hydrothermal method, using citrate moiety as capping agent. Y3+ ions have been introduced in the crystal structure to declusterize the Nd3+ ions and improve the emission properties. After a structural and morphological characterization of the obtained NPs, the optical properties of colloidal dispersions have been analyzed in the near infrared (NIR) range. The emission spectra reveal several transitions associated with different sites where the Nd3+ ions are accommodated in the crystal structure. Some bands show a marked dependence on the temperature, and a thermometric investigation reveals good thermal relative sensitivities in the physiological temperature range (20-60 degrees C), proving the applicability of the investigated colloidal NPs as optical nanothermometers.

The use of multiple wavelengths to excite Titanium Dioxide Raman scattering in the near-infrared was investigated for optical nanothermometry. Indeed, Raman spectroscopy can be a very interesting technique for this purpose, as it offers non-disruptive contactless measurements with a high spatial resolution, down to a few µm. A method based on the ratio between the anti-Stokes and Stokes peaks of Anatase Titanium Dioxide was proposed and tested at three different wavelengths, 785, 800 and 980 nm, falling into the first biological transparency window (BTW-I). Using a temperature-controller stage, the temperature response of the sample was measured between 20 and 50 °C, allowing the thermal sensitivity for this range to be estimated. The use of sufficiently high laser power results in the generation of local heating. A proof of concept of the proposed thermometric method was performed by determining the extent of local heating induced by increasing laser power. By exciting with an 800 nm laser at low power intensities, a temperature equal to room temperature (RT) was found, while a maximum temperature increase of 15 °C was detected using the anti-Stokes/Stokes method.

The ability to control and understand the temperature at the nanoscale is fundamental for manipulating physical, chemical, and biological processes [...]

Determining temperature changes at the heating site to accurately control thermal treatments has been a major goal in the field of nanothermometry. In this study, we address the need to effectively monitor local temperature during the application of photothermal therapies, which is essential to prevent uncontrolled heating induced by nanoparticle sensitizers used in such treatments. For this purpose, we developed a synthetic protocol to produce a nanocomposite probe that allows local photothermal heating and simultaneous in situ optical nanothermometry, within the biological transparency windows. The nanocomposite material comprises gold nanorods for light-to-heat conversion and neodymium (Nd3+)-based nanoparticles for local temperature monitoring. An inert spacer made of mesoporous silica provides a core-shell structure and ensures uniform separation between both functionalities to prevent photoluminescence quenching. By using an 808 nm laser as the source for both heating and photoluminescence excitation, we demonstrate a direct correlation between local temperature and near-infrared Nd3+ emission intensities, thereby providing precise local temperature monitoring. Different levels of local heating were studied by varying the incident laser power, resulting in a maximum temperature increase of 47 degrees C detected with the nanothermometers. Albeit presented here as a proof of concept, this configuration can be translated to the design of materials for photothermal therapy.

The unique electrical properties of silicon nitride have increased the applications in microelectronics, especially in the manufacture of integrated circuits. Silicon nitride is mainly used as a passivation barrier against water and sodium ion diffusion and as an electrical insulator between polysilicon layers in capacitors. The interface with different materials, like semiconductors and metals, through soldering may induce residual strains in the final assembly. Therefore, the dentification and quantification of strain becomes strategically important in optimizing processes to enhance the performance, duration, and reliability of devices. This work analyzes the thermomechanical local strain of semiconductor materials used to realize optoelectronic components. The strain induced in the β-Si3N4 chips by the soldering process performed with AuSn pre-formed on copper substrates is investigated by Raman spectroscopy in a temperature range of −50 to 180 °C. The variation in the position of the E1g Raman peak allows the calculation of the local stress present in the active layer, from which the strain induced during the assembly process can be determined. The main reason for the strain is attributed to the differences in thermal expansion coefficients among the various materials involved, particularly between the chip, the interconnection material, and the substrate. Micro-Raman spectroscopy allows for the assessment of how different materials and assembly processes impact the strain, enabling more informed decisions to optimize the overall device structure.

The accurate determination of the local temperature is one of the most important challenges in the field of nanotechnology and nanomedicine. For this purpose, different techniques and materials have been extensively studied in order to identify both the best-performing materials and the techniques with greatest sensitivity. In this study, the Raman technique was exploited for the determination of the local temperature as a non-contact technique and titania nanoparticles (NPs) were tested as nanothermometer Raman active material. Biocompatible titania NPs were synthesized following a combination of sol-gel and solvothermal green synthesis approaches, with the aim of obtaining pure anatase samples. In particular, the optimization of three different synthesis protocols allowed materials to be obtained with well-defined crystallite dimensions and good control over the final morphology and dispersibility. TiO2 powders were characterized by X-ray diffraction (XRD) analyses and room-temperature Raman measurements, to confirm that the synthesized samples were single-phase anatase titania, and using SEM measurements, which clearly showed the nanometric dimension of the NPs. Stokes and anti-Stokes Raman measurements were collected, with the excitation laser at 514.5 nm (CW Ar/Kr ion laser), in the temperature range of 293–323 K, a range of interest for biological applications. The power of the laser was carefully chosen in order to avoid possible heating due to the laser irradiation. The data support the possibility of evaluating the local temperature and show that TiO2 NPs possess high sensitivity and low uncertainty in the range of a few degrees as a Raman nanothermometer material.

The determination of the local temperature is an interesting and intriguing topic in the nanotechnology and nanomedicine world, in terms of tuning the best noninvasive measurement protocol and identification of the more versatile and performing material.In this paper, the Raman technique and titania NPs have been exploited for the realization of a new optical nanotermometer.Biocompatible titania NPs have been properly synthesized, following a combination of sol-gel and solvothermal green synthesis approaches, with the aim of obtaining samples of pure anatase, characterized by crystallite dimensions defined and good control over the final morphology and dispersibility.Powder XRD measurements and room temperature Raman measurements confirmed that the synthesized samples are single-phase anatase.The SEM images clearly showed the nanometric dimension of NPs.Stokes and anti-Stokes Raman measurements, collected with the excitation laser at 514.5 nm (CW Ar/Kr ion laser), substantiate the possibility of evaluating the local temperature, which has been tested in the range of 298 -313 K, a range of interest for biological applications.The power of the laser has been carefully chosen in order to avoid eventual heating due to the laser irradiation.The data show that TiO2 NPs possess a high sensitivity and low uncertainty in the range of a few degrees as Raman nanothermometer material.

The growing interest in improving optoelectronic devices requires continuous research of the materials and processes involved in manufacturing. From a chemical point of view, the study of this sector is crucial to optimize existing manufacturing processes or create new ones. This work focusses on the experimental evaluation of residual stresses on samples that are intended to simulate part of the structure of an optoelectronic device. It represents an important starting point for the development of optoelectronic devices with characteristics suitable for future industrial production. Silicon chips, with a thickness of 120 μm, were soldered onto copper and alumina substrates, using different assembly parameters in terms of temperature and pressure. Using Raman spectroscopy, the stress evaluation was estimated in a wide temperature range, from −50 to 180 °C. Silicon chips soldered with AuSn alloy on copper substrates demonstrated at 22 °C a compressive stress, developed in the center of the assembly with a maximum value of −600 MPa, which reached −1 GPa at low temperatures. They present a stress distribution with a symmetric profile with respect to the central area of the chip. The silicon chip assembled on a ceramic substrate without pressure turned out to be extremely interesting. Even in the absence of pressure, the sample did not show a large shift in the Raman position, indicating a low stress.

Local temperature determination is essential to understand heat transport phenomena at the nanoscale and to design nanodevices for biomedical, photonic, and optoelectronic applications. In particular, the detection of the local temperature of the intracellular environment is interesting for photothermal therapy. In the present work, nanoparticles consisting of an Ag core, covered by a TiO2 shell and Ag@TiO2 core–shell, were suitably synthesized through a one-pot method. Silver nanoparticles synthesized in DMF were coated by controlled hydrolysis of titanium tetrabutoxide in the same reaction environment. The synthesis led to nanocomposites where AgNPs were covered by a diffuse layer of anatase. The nanocomposites were characterized using UV/Vis spectroscopy and Raman spectroscopy. The samples obtained proved to be good Raman nanothermometers with a sensitivity comparable to that of simple anatase nanoparticles.