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Photo‐ATRP technique has garnered significant attention due to its multitude of advantages, including its ability to be conducted under mild reaction conditions, user‐friendly nature, and exceptional efficiency in polymerization. The heterogeneous photocatalysts not only exhibit exceptional quantum efficiency, but also possess a versatile bandgap that can be finely adjusted to accommodate a wide range of absorption wavelengths within the visible light spectrum, thereby emphasizing their potential for efficient recovery and reuse. The utilization of a variety of heterogeneous photocatalysts in photo‐ATRP presents notable benefits for numerous applications, such as the lack of any remaining substances, simplicity in usage, and potential for reuse. This review focuses on recent progress in photo‐ATRP utilizing a wide variety of heterogeneous photocatalysts, encompassing metal semiconductor nanoparticles, quantum dot, upconversion nanoparticles, metal–organic frameworks, covalent–organic frameworks, conjugated microporous polymers, hypercrosslinked polymer, and carbon‐based materials. [ABSTRACT FROM AUTHOR]

Photon-upconversion nanoparticles (UCNP) have already been established as labels for affinity assays in analog and digital formats. Here, advanced, or smart, systems based on UCNPs coated with active shells, fluorescent dyes, and metal and semiconductor nanoparticles participating in energy transfer reactions are reviewed. In addition, switching elements can be embedded in such assemblies and provide temporal and spatial control of action, which is important for intracellular imaging and monitoring activities. Demonstration and critical comments on representative approaches demonstrating the progress in the use of such UCNPs in bioanalytical assays, imaging, and monitoring of target molecules in cells are reported, including particular examples in the field of cancer theranostics. [ABSTRACT FROM AUTHOR]

Because of their quantum confinement effects and adjustable features, semiconductor nanoparticles have attracted a lot of attention for their various uses in optoelectronic devices. This study investigates how size and shape variations affect the optoelectronic properties of semiconductor nanoparticles InX (X = As, Sb, and P). Using unified thermodynamics modeling, it explores the effects of these nanoparticles' diameters on their electronic band structures, optical properties, and charge carrier dynamics. The inquiry focuses on InX nanoparticles with different sizes and nanostructure morphologies. By examining electronic band structures, the density of states, and optical absorption spectra, the size-dependent quantum confinement processes that govern the optical band gap transitions and excitonic behaviors in these semiconductor nanoparticles were made clear. Also, the influence of the shape of the nanoparticles on carrier mobility and electronic band alignment is investigated, offering insights into the possibility of controlling the morphology to customize optoelectronic capabilities. This theoretical analysis indicates that altering the optoelectronic properties of InX semiconductor nanoparticles is mostly dependent on their size and shape. Smaller nanoparticles show stronger quantum size effects, which lead to improved exciton confinement and blue shifts in the optical absorption spectra. Shape-dependent differences in the density of states and electronic band structures indicate the impact of morphology on the dynamics and recombination of charge carriers in the nanoparticles. In conclusion, this work provides important insights for the design and optimization of semiconductor nanomaterials for photovoltaic, sensing, and light-emitting applications by thoroughly examining the impact of size and shape on the optoelectronic properties of InX semiconductor nanoparticles. [ABSTRACT FROM AUTHOR]

Metal or semiconductor nanoparticles (NPs) can enhance the device performance of gas sensors due to their high surface area and unique electronic properties. However, this method requires additional thermal bonding with high temperatures to secure the NPs, making it unsuitable for flexible substrates. In this study, we develop a room-temperature flexible ozone (O 3) gas sensor using Mn 3 O 4 NPs on an amorphous InGaZnO (a-IGZO) film. The Mn 3 O 4 NPs are synthesized by a successive ionic layer adsorption and reaction (SILAR) method at low temperatures. The sensor with Mn 3 O 4 NPs exhibits a gas response of 4.06 against 5 ppm O 3 gas at room temperature, which is much higher than that of its pristine counterpart. It also shows excellent selectivity for O 3 over toxic gases and maintains stability over 60 days, with reproducible folding even after 500 bending cycles. Thus, the combination of SILAR-synthesized Mn 3 O 4 NPs and a-IGZO films provides an effective way to fabricate flexible O 3 gas sensors. [ABSTRACT FROM AUTHOR]

Herein, CdTe/MnS core/shell nanoparticles dispersed in an aqueous solution have been synthesized. The formation of MnS semiconductor shell occurs by spontaneous self‐assembly. This process is activated by thermal hydrolysis that removes the excess of thiol and releases S2− ions. In this process, Mn2+ ions on the surface of the CdTe nanoparticles bind to S2− ions to produce a fine semiconducting layer of MnS. Measurements of Raman spectroscopy, optical absorption, and electrochemical measurements are performed. The Raman spectrum shows CdTe characteristic bands at 141 and 163 cm−1. Bands at 221 and 444 cm−1 are associated with the MnS structure. Cyclic voltammetry and differential pulse voltammetry are used to estimate the electrochemical gap at ≈2.47 eV. Absorption optical measurements show tree absorption bands. A broad band between 460 and 520 nm is associated with the first transition in CdTe nanoparticle. The absorption spectrum reveals an optical gap in the range of 2.41–2.33 eV for all the refluxed samples. These values are consistent with those obtained with the electrochemical measurements. The results evidence the formation of a core–shell semiconducting nanostructure made of CdTe nanoparticles coated with a spontaneously self‐assembled thin layer of MnS nanoparticles. [ABSTRACT FROM AUTHOR]

The physical mechanism of the quantum size effect, which determines the main feature of the size dependence of absorption and photoluminescence spectra of nanoparticles of semiconductor materials, is outlined, and the effects of multiexciton generation and luminescence blinking of colloidal quantum dots are discussed. [ABSTRACT FROM AUTHOR]

Aggregates created by a simple physical method promote the charge mobility between semiconductor nanoparticles and, combined with the selective photo-deposition of platinum, dramatically improve the hydrogen production when low loadings of Pt are used. [Display omitted] Photocatalysis has emerged as a promising and environmentally sustainable solution to produce high-purity hydrogen through ethanol photoreforming. It is commonly accepted that adding co-catalysts, especially noble metals, significantly enhances the catalytic activity of semiconductors. However, the high cost of noble metals such as Pt may limit the real application of this emerging technology. Here we evaluate the possibility of reducing the noble metal loading by creating the appropriate interface between pre-formed semiconductor nanoparticles. Commercial titania (P25) was selected as the semiconductor due to its commercial availability, facilitating the straightforward validation and corroboration of our results. Pt was selected as co-catalyst because one of the most efficient photocatalysts for the ethanol photo-reforming is still based on the use of P25 in combination with Pt. We report that the creation of induced aggregates dramatically improves the total hydrogen produced when very low loadings (≤0.05 wt%) of Pt are used. We have developed a pioneering reactor designed for conducting photoluminescence studies under authentic operational conditions of nanoparticle suspensions in the liquid phase. This approach allows us to obtain the average photoluminescence emission from the P25 agglomerates what it would be impossible to obtain by using standard solid samples holders. Thanks to this equipment, we can conclude that this remarkable improvement of the activity is mainly due to creation of an interface that favors the charge transfer between the particles of the aggregates. According to this, the titania nanoparticles of the agglomerates act as an antenna to collect the photons of the sun-light and produce the photo-excited electrons that will be transferred to the platinum nanoparticles located in the same agglomeration. In contrast, raw P25 with low loadings of Pt would have a high number of titania nanoparticles without platinum, and therefore, inactive. This result would be especially relevant in the case of immobilized photocatalytic systems for real future photocatalytic reactors because the immobilization of the semiconductors would generate similar interactions to the one created by our method. Consequently, the initial semiconductor immobilization followed by the subsequent photo-deposition of the co-catalyst emerges as a promising approach for a substantial reduction of the co-catalyst content. [ABSTRACT FROM AUTHOR]

Colloidal semiconductor nanoparticles (NPs) represent an emergent state of matter with unique properties, bridging bulk materials and molecular structures. Their distinct physical attributes, such as bandgap and photoluminescence, are intricately tied to their size and morphology. Ligand passivation plays a crucial role in shaping NPs and determining their physical properties. Ligand exchange (LE) offers a versatile approach to tailoring NP properties, often guided by Pearson's Hard–Soft Acid–Base theory. Lead sulfide (PbS), a semiconductor of considerable interest, exhibits size-dependent tunable bandgaps from the infrared to the visible range. Here, we present two methods for synthesizing water-soluble, polyvinylpyrrolidone (PVP)-coated PbS NPs. The first involves direct synthesis in an aqueous solution while utilizing PVP as the surfactant for the formation of nano-cubes with a crystal coherence length of ~30 nm, while the second involves LE from octadecylamine-coated PbS truncated nano-cubes to PVP-coated PbS NPs with a crystal coherence length of ~15 nm. Multiple characterization techniques, including X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermal gravimetric analysis, confirmed the results of the synthesis and allowed us to monitor the ligand exchange process. Our findings demonstrate efficient and environmentally friendly approaches for synthesizing PVP-coated PbS NPs. [ABSTRACT FROM AUTHOR]

Here, the optical properties of the Nafion polymer membrane containing colloidal CdSe/CdS/ZnS nanocrystals embedded by diffusion have been studied. The CdSe/CdS/ZnS nanocrystals have a core/shell/shell appearance. All experiments were carried out at room temperature (22 ± 2) °C. A toluene solution was used to provide mobility to the active sulfone groups of the Nafion membrane and to embed the nanocrystals inside the membrane. The diffusion process of colloidal CdSe/CdS/ZnS nanocrystals into Nafion proton exchange membrane has resulted in a new molecular complex "Nafion–colloidal CdSe/CdS/ZnS nanocrystals". The kinetics of the nanocrystals embedding into the membrane matrix was investigated using luminescence analysis and absorption spectroscopy techniques. The embedding rate of CdSe/CdS/ZnS nanocrystals into the Nafion polymer membrane was approximately 4·10−3 min−1. The presence of new luminescence centers in the membrane was proved independently by laser emission spectroscopy. The luminescence spectrum of the resulting molecular complex contains intensity maxima at wavelengths of 538, 588, 643 and 700 nm. The additional luminescence maximum observed at the 643 nm wavelength was not recorded in the original membrane, solvent or in the spectrum of the semiconductor nanoparticles. The luminescence maximum of the colloidal CdSe/CdS/ZnS nanocrystals was registered at a wavelength of 634 nm. The intensity of the luminescence spectrum of the membrane with embedded nanocrystals was found to be higher than the intensity of the secondary emission peak of the initial nanocrystals, which is important for the practical use of the "Nafion–colloidal nanocrystals" complex in optical systems. The lines contained in the luminescence spectrum of the membrane, which has been in solution with colloidal nanocrystals for a long time, registered upon its drying, show the kinetics of the formation of the molecular complex "Nafion membrane–nanocrystals". Colloidal nanocrystals located in the Nafion matrix represent an analog of a luminescent transducer. [ABSTRACT FROM AUTHOR]

Pb2+ codoping enhances the Tb3+ emission in trivalent terbium-doped zinc sulfide [Zn-(Tb)-S] nanoparticles (NPs). The Tb3+-Pb2+ spatial proximity and a favorable codopant electronic energy level alignment contribute toward this emission brightening. This work tests the performance of the Tb3+ emission in the Zn-(TbPb)S and Zn-(Tb)-S/Pb NPs, where the dopants within parentheses and after slashes indicate their synthetic and postsynthetic doping, respectively. When screened against steady-state and time-resolved photoluminescence, photoelectron spectroscopy, zeta potential, and infrared absorption of surface capping ligands, the Zn-(TbPb)S NPs emerge as a superior sensitizer to generate Tb3+ emission. A core dominant Tb3+-Pb2+ interaction in Zn-(TbPb)S NPs prompts a stronger Tb3+ emission when compared to the surface dominant Tb3+-Pb2+ interaction in Zn-(Tb)-S/Pb NPs. This doping strategy guided the NP design principle to control lanthanide emission, which expands the palette of lanthanide-based NP luminophores for practical applications. The Pb2+‑sensitized Tb3+ emission brightening in the ZnS NPs in the precation exchange reaction conditions can find applications in Pb2+ sensing, cellular imaging, and light emitting diodes (LEDs). [ABSTRACT FROM AUTHOR]

Introduction: Polymetallic sulfides and heterostructures like CdIn2S4, CdZnS2, CuxS‐NiySz, Cu2CoSnS4, CoNi2S4, Zn0.76Co0.24S have been fabricated with various shapes and forms for new applications. Ternary copper cadmium sulfides (CuCdS2) are a p‐type semiconductor with a direct band gap of about 2.4 eV forms very good nanocrystals like copper sulfide could be potentially applied to optical and electronic applications. Knowing that the SILAR synthesis, optical, paramagnetic, dielectric properties, and annealing of copper cadmium sulfides have not been sufficiently investigated, they are extensively analyzed and studied in the present work. Objectives: CuxCd1−xS (x = 0, 0.5, and 1) nanoparticles have been synthesized on the base of functionalized nitrile butadiene rubber by SILAR method and characterized using scanning electron microscopy, x‐ray diffractometer, UV–visible spectroscopy, Fourier‐transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and Raman spectroscopy. Effects of cycles, reaction time, and precursor concentration on the particle size, crystal growth and structure, bandgap energy, dielectric and paramagnetic properties, elemental composition, and morphology were investigated. Methods: The synthesis of CuxCd1−xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. The functional polymer (FNBR) is a dark brown powder which contains ‐PO(OH)2 and ‐OPO(OH)2 functional groups and does not dissolve in organic and inorganic solvents, can be used as a very good stabilizer of nanostructures. The synthesis of CuxCd1−xS/FNBR nanocompsite was carried out in 3, 5, and 15 cycles. Results and discussion: In the process of ternary sulfide formation, the nucleation rate of CdS was high at the beginning of the reaction, while the growth rate and stability of CuS were high in the later course of the reaction. The average crystallite size of the nancrystallites has been increased from 1.13 nm to 7.39 nm by the increasing of the number of cycles from 5 to 15, respectively. It is explained by the inclusion of copper in the composition and getting more stable material. Copper cadmium sulfide nanostructures demonstrate wide band gap energy (~3.7 eV) in this work which is explained by the formation of nanosized particles in a limited volume of FNBR matrix. Conclusions: The synthesis of CuxCd1‐xS nanocrystals was carried out into the obtained functional polymer matrix by SİLAR method. Strong diffraction peaks corresponding to cubic CdS are found with low SILAR cycles. SEM images of CuxCd1−xS/FNBR nanocomposite show that the atomic percentage of Cu and Cd into the ternary sulfide is 20.19% and 0.61%, respectively. It is explained by the inclusion of copper in the composition and getting more stable material with low solubility products (Ksp) which is in good agreement with XRD results. The calculated band gaps are higher than that of bulk CdS, CuS, and CuCdS2. Larger band gap is usually reported for defects or structural disorders, which is in good agreement with XRD and Raman results. [ABSTRACT FROM AUTHOR]

Small-size gold nanoparticles (AuNPs) are showing large potential in various fields, such as photothermal conversion, sensing, and medicine. However, current synthesis methods generally yield lower, resulting in a high cost. Here, we report a novel uni-micelle method for the controlled synthesis of monodisperse gold nanocrystals, in which there is only one kind micelle containing aqueous solution of reductant while the dual soluble Au (III) precursor is dissolved in oil phase. Our synthesis includes the reversible phase transfer of Au (III) and "uni-micelle" synthesis, employing a Au (III)-OA complex as an oil-soluble precursor. Size-controlled monodisperse AuNPs with a size of 4–11 nm are synthesized by tuning the size of the micelles, in which oleylamine (OA) is adsorbed on the shell of micelles and enhances the rigidity of the micelles, depressing micellar coalescence. Monodisperse AuNPs can be obtained through a one-time separation process with a higher yield of 61%. This method also offers a promising way for the controlled synthesis of small-size alloy nanoparticles and semiconductor heterojunction quantum dots. [ABSTRACT FROM AUTHOR]

The growth of germanium nanoparticles' thin films on rough SiO 2 surfaces through the sputtering technique was analyzed based on thermodynamic principles. The study proposes a predictive model that allows controlling the size, distribution, and crystalline quality of nanoparticles embedded in oxides by adjusting the corresponding growth parameters in reactive sputtering. Surfaces based on two-dimensional Brownian motion, a precise modeling technique, were used to model the rough surface. A mathematical relation between the Hurst exponent and root mean square of a surface measured is used to reconstruct theoretical roughness surfaces. The modeling predictions were compared with statistical results obtained through atomic force microscopy measurements. Additionally, we find that the interfacial thin film-surface energy impacts the crystallization process. [ABSTRACT FROM AUTHOR]

This study details the synthesis, characterization, and photocatalytic efficacy of zinc oxide (ZnO) nanoparticles (NPs) obtained through an environmentally friendly method with varying quantities of Rubus glaucus as a chelating agent. Examination of X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) data unveiled ZnO NPs featuring a wurtzite structure and sizes ranging from 43.39 to 28.01 nm. The analysis indicated that the presence of Rubus glaucus extract during synthesis influenced the size and band gap of the ZnO NPs, resulting in a decrease from 2.8 to 2.5 eV. The photocatalytic performance of ZnO NPs was assessed through the degradation of synthetic dyes methylene blue (MB), methyl orange (MO), and rhodamine B (RhB). The results demonstrated enhanced photocatalytic activity for the ZnO NPs, with ZnO-RG3 exhibiting the most effective degradation. Under UV light, ZnO-RG3 degraded 99%, 95%, and 95% of MB, MO, and RhB within 90 min, while under sunlight, it achieved degradation rates of 98%, 85%, and 95% for MB, MO, and RhB within the same timeframe. These findings underscore the effectiveness of Rubus glaucus extract as a chelating agent in producing metal oxide nanoparticles with remarkable photocatalytic performance under both UV and sunlight conditions. [ABSTRACT FROM AUTHOR]

One of the most pressing issues that the world is currently facing is water contamination. Photocatalysis using semiconductor nanoparticles (NPs) is a promising and potential alternative for water treatment. In this research, zinc oxide (ZnO) NPs were synthesized using Ternstroemia pringlei Rose (FT), Turnera diffusa Willd (DC), and Agastache mexicana (TM) extracts, as an eco-friendly approach. The properties of ZnO NPs were evaluated by different characterization techniques. According to XRD patterns, a hexagonal Wurtzite structure was achieved for all syntheses. FTIR spectra exhibited stretching vibrations of the Zn–O bond at 397 cm−1, which indicates the formation of ZnO. The bandgap was found to vary depending on the extract source. Furthermore, PL spectra showed UV and visible emission associated with free exciton and structural defects in ZnO. A quasi-spherical shape and sizes of less than 20 nm were releveled by SEM and TEM. ZnO NPs, using DC and TM extracts, demonstrated and highlighted the influence in the efficient degradation of Methylene blue (MB), Malachite green (MG), and Congo red (CR); however, the Rhodamine B (RB) and methyl orange (MO), presented a slow degradation independent of the extract used for ZnO synthesis. The green method using FT, DC, and TM extracts offers a suitable route for ZnO production with promising applications in sustainable water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Achieving a controlled preparation of nanoparticle superstructures with spatially periodic arrangement, also called superlattices, is one of the most intriguing and open questions in soft matter science. The interest in such regular superlattices originates from the potentialities in tailoring the physicochemical properties of the individual constituent nanoparticles, eventually leading to emerging behaviors and/or functionalities that are not exhibited by the initial building blocks. Despite progress, it is currently difficult to obtain such ordered structures; the influence of parameters, such as size, softness, interaction potentials, and entropy, are neither fully understood yet and not sufficiently studied for 3D systems. In this work, we describe the synthesis and characterization of spatially ordered hierarchical structures of coated cerium oxide nanoparticles in water suspension prepared by a bottom-up approach. Covering the CeO 2 surface with amphiphilic molecules having chains of appropriate length makes it possible to form ordered structures in which the particles occupy well-defined positions. In the present case superlattice arrangement is accompanied by an improvement in photoluminescence (PL) efficiency, as an increase in PL intensity of the superlattice structure of up to 400 % compared with that of randomly dispersed nanoparticles was observed. To the best of our knowledge, this is one of the first works in the literature in which the coexistence of 3D structures in solution, such as face-centered cubic (FCC) and Frank-Kasper (FK) phases, of semiconductor nanoparticles have been related to their optical properties. [ABSTRACT FROM AUTHOR]

In this research, zinc oxide semiconductor nanoparticles doped with copper and iron elements were synthesized by the reverse co-precipitation method and their electrical and magnetic properties were investigated. The results of XRD analysis of ZnO nanoparticles showed that high-purity nanoparticles were produced, and the presence of the added dopants did not change the hexagonal structure of zinc oxide despite the slight changes in crystallite size. Besides, the results of the FESEM analysis revealed the morphology and the size of 25 nm for the nanoparticles. Furthermore, the results of PL and DRS-UV analysis showed that the band gap and optical and electrical properties of the dopant zinc oxide nanoparticles have been enhanced compared to the zinc oxide. Finally, the magnetic characteristics of these nanoparticles was investigated using the VSM analysis, and the results showed appropriate ferromagnetic properties. In conclusion, the results demonstrate the success of the reverse co-deposition method by using a non-ionic surfactant (Span 80) in the production of Cu2+- doped and Fe2+- doped ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

CdxZn1−xS nanoparticles have been synthesized on the base of functionalized nitrile butadiene rubber (FNBR) by SILAR method and characterized by various techniques. Both binary and ternary sulfide nanocrystals have been obtained in the cubic phase with very high purity at room temperature. The average particle size decreased from 2.49 nm to 2.22 nm and then increased to 2.44 nm by the increasing of zinc concentration from 25 % to 50 % and 75 %. The calculated Young's modulus for (111), (220) and (311) planes are 97.84, 78.51 and 64.33 m2 N−1 for CdS and 95.84, 69.68, 53.42 m2 N−1 for ZnS, respectively. The band corresponding PO32− (977 cm−1) shifted to 969, 975, 972, 973, and 972 cm−1 upon the formation of CdS, ZnS, Cd0.5Zn0.5S, Cd0.75Zn0.25S and Cd0.25Zn0.75S nanoparticles into FNBR matrix, which is explained by Hooke's Law. EPR spectra of CdS/FNBR nanocomposite show broad and singlet asymmetric, isotropic symmetry (gx=gy=gz). The appearance of a new line in the 3518 G magnetic field is observed in both CdS and Cd0.5Zn0.5S compounds' spectra.The total mass loss of the samples NBR, FNBR, Cd2+ and Zn2+ ions containing FNBR are 93.76, 59.77, 60.03 and 57.79 %, respectively. High crystallinity is caused by complete interaction of metal ions with functional groups during the nucleation. [ABSTRACT FROM AUTHOR]

Conductive polymer composites (CPCs), obtained by incorporating conductive fillers into a polymer matrix, are suitable for producing strain sensors for structural health monitoring (SHM) in infrastructure. Here, the effect of the addition of inorganic semiconductor nanoparticles (INPs) to a poly (vinylidene fluoride) (PVDF) composite filled with multi-walled carbon nanotubes (MWCNTs) on the piezoresistive behavior is investigated. INPs with different morphologies and sizes are synthesized by a hydrothermal method. The added inorganic oxide semiconductors showed two distinct morphologies, including different phases. While particles with flower-like plate morphology contain phases of orth-ZnSnO3 and SnO, the cauliflower-like nanoparticles contain these metal oxides and ZnO. The nanoparticles are characterized by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD), and the nanocomposites by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Cyclic tensile testing is applied to determine the strain-sensing behavior of PVDF/1 wt% MWCNT nanocomposites with 0–10 wt% inorganic nanoparticles. Compared to the PVDF/1 wt% MWCNT nanocomposite, the piezoresistive sensitivity is higher after the addition of both types of nanoparticles and increases with their amount. Thereby, nanoparticles with flower-like plate structures improve strain sensing behavior slightly more than nanoparticles with cauliflower-like structures. The thermogravimetric analysis results showed that the morphology of the semiconductor nanoparticles added to the PVDF/MWCNT matrix influences the changes in thermal properties. [ABSTRACT FROM AUTHOR]

The accelerating use of organic dyes in various industries has led to a surge in water pollution, especially from non-biodegradable dye effluents discharged into water resources. This study addresses the critical issue of catalyzing the reduction of two prevalent dyes, methylene blue (MB) and rhodamine-B (RhB), using a multiwalled carbon nanotube-cobalt ferrite (MWCNT-CF) nanocomposite. The synthesized nanocomposite demonstrates exceptional catalytic activity, stability, and recyclability. Conventional methods for treating dye-containing wastewater often prove expensive. This study explores the efficacy of catalytic reduction, a relatively fast process facilitated by semiconductor nanoparticles. Structural analyses using X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) confirm the formation of the nanocomposite, revealing unsaturated surface bonds and chains conducive to adsorption. The nanocomposite exhibits a remarkable reduction in both dyes, with easy recyclability for multiple cycles. Magnetization studies confirm the ferrimagnetic nature of the nanocomposite, facilitating its efficient separation from the reaction mixture using a magnet. The study delves into the kinetics of the catalytic reduction following pseudo-first-order kinetics. The surface modifications of the nanocomposite, as revealed by TEM, contribute to enhanced adsorption and catalytic efficiency. Notably, the MWCNT-CF nanocomposite demonstrates negligible loss of catalytic activity during recycling, highlighting its potential for cost-effective and sustainable applications in dye reduction across various industries. [ABSTRACT FROM AUTHOR]

Quantum dots are semiconductor nanoparticles containing a range of materials with a core-shell structure. They receive discernible attention in today's world due to their potential applications, from energy storage devices to medical applications. Nevertheless, there are many approaches to their synthesis and stability routes. This review focuses on two approaches for the synthesis of quantum dots, namely surface functionalization and quantum dot doping. In addition, their stability routes were discussed, such as the intermediate shell approach, alloyed core/shell approach, shell thickness approach, ligand design approach, and over-coating approach. The review concludes by addressing the recent progress of quantum dots applications, notably in photocatalysis for different applications, such as cathode, anode, and membranes for fuel cell applications, solar cells, sensors, and various energy storage devices applications. • QDs are characterized by their tunable size, composition, and fluorescence features. • Functionalization and doping of QDs are the main remarkable achievements in synthesis. • The stability of QDs can be enhanced by following the core-shell structure. • QDs can be stabilized by the intermediate shell approach, alloyed core/shell approach, and overcoating approach. [ABSTRACT FROM AUTHOR]

The optical properties of light-absorbing materials in optical shutter devices are critical to the use of such platforms for optical applications. We demonstrate switchable optical properties of dyes and nanoparticles in liquid-based electrowetting-on-dielectric (EWOD) devices. Our work uses narrow-band-absorbing dyes and nanoparticles, which are appealing for spectral-filtering applications targeting specific wavelengths while maintaining device transparency at other wavelengths. Low-voltage actuation of boron dipyromethene (BODIPY) dyes and nanoparticles (Ag and CdSe) was demonstrated without degradation of the light-absorbing materials. Three BODIPY dyes were used, namely Abs 503 nm, 535 nm and 560 nm for dye 1 (BODIPY-core), 2 (I2BODIPY) and 3 (BODIPY-TMS), respectively. Reversible and low-voltage (≤20 V) switching of dye optical properties was observed as a function of device pixel dimensions (300 × 900, 200 × 600 and 150 × 450 µm). Low-voltage and reversible switching was also demonstrated for plasmonic and semiconductor nanoparticles, such as CdSe nanotetrapods (abs 508 nm), CdSe nanoplatelets (Abs 461 and 432 nm) and Ag nanoparticles (Abs 430 nm). Nanoparticle-based devices showed minimal hysteresis as well as faster relaxation times. The study presented can thus be extended to a variety of nanomaterials and dyes having the desired optical properties. [ABSTRACT FROM AUTHOR]

Chiral semiconductor nanostructures and nanoparticles are promising materials for applications in biological sensing, enantioselective separation, photonics, and spin-polarized devices. Here, we studied the induction of chirality in atomically thin only two-monolayer-thick CdSe nanoplatelets (NPLs) grown using a colloidal method and exchanged with L-alanine and L-phenylalanine as model thiol-free chiral ligands. We have developed a novel two-step approach to completely exchange the native oleic acid ligands for chiral amino acids at the basal planes of NPLs. We performed an analysis of the optical and chiroptical properties of the chiral CdSe nanoplatelets with amino acids, which was supplemented by an analysis of the composition and coordination of ligands. After the exchange, the nanoplatelets retained heavy-hole, light-hole, and spin-orbit split-off exciton absorbance and bright heavy-hole exciton luminescence. Capping with thiol-free enantiomer amino acid ligands induced the pronounced chirality of excitons in the nanoplatelets, as proven by circular dichroism spectroscopy, with a high dissymmetry g-factor of up to 3.4 × 10−3 achieved for heavy-hole excitons in the case of L-phenylalanine. [ABSTRACT FROM AUTHOR]

In the present study, the highly recommended lead iodide (PbI2) nanoparticles and thin films based on PbI2 nanoparticles have been prepared for optoelectronics and solar cell applications. PbI2 is an anisotropic p-type semiconductor with a band gap of 2.57 eV at room temperature. PbI2 material has large potential applications in optical detector, digital X-ray imaging, gamma ray detector, etc. PbI2 layered semiconductor nanoparticles were stabilized using thioglycerol and investigated by Ultraviolet-Visible (UV-Vis) absorption spectroscopy, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The chemical bath deposition (CBD) method was used to deposit PbI2 thin films on fluorine-doped tin oxide (FTO) glass substrates. These films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), mapping and atomic force microscopy (AFM). The thicknesses of the PbI2 thin films were estimated using a laser profilometer. The blue shift was observed in UV-Vis absorption and PL spectra of PbI2 nanoparticles. TEM was used to obtain quantitative information on the PbI2 particle size distribution. Due to the low solubility of PbI2 in acetonitrile, approximately 20-30 nm sized circular particles are obtained. The variation of 18 Å was observed in the lateral dimensions of PbI2 nanoparticles. Pb4fXPS core level appeared at 138.5 eV corresponding to PbI2. There is no report published wherein the PbI2 nanoparticles and the PbI2 thin films were prepared by the aqueous chemical method and the CBD method respectively. In this study, the characterization results of PbI2 nanoparticles and PbI2 thin films were better than many other materials. [ABSTRACT FROM AUTHOR]

Dilute magnetic semiconductor nanoparticles of zinc phosphide (Zn3-xNixP2), doped with nickel, were synthesized using a solid-state reaction method. The doping levels of nickel were varied at x = 0.01, 0.03, 0.05, and 0.07. The study investigated the influence of varying nickel dopant concentrations on the structural, optical, and magnetic characteristics of the synthesized materials. Based on the XRD investigation, it is evident that the generated samples have a tetragonal structure, with no discernible presence of additional nickel or any other contaminants in the diffraction peaks. The lattice parameters exhibited a positive correlation with the Ni content, indicating that an increase in Ni concentration led to an increase in lattice parameters. SEM pictures provided empirical evidence supporting the notion that the dimensions of the nanoparticles exhibited a positive correlation with the extent of dopant incorporation. EDS examination indicates that the concentration of dopants closely approximates the desired atomic ratio. The optical band gap of the Zn3-xNixP2 nanoparticles exhibited a rise in value, namely from 1.410 to 1.433 eV, as the quantity of nickel was increased. The study revealed that photoluminescence emission peaks were consistently seen at nearly identical places, despite variations in excitation wavelengths. Additionally, it was noted that the strength of the emission peaks exhibited slight fluctuations, which were more pronounced as the concentration of the dopant rose. The study of the VSM data demonstrates a positive correlation between saturation magnetization and the Ni content, indicating that an increase in the Ni concentration leads to an increase in saturation magnetization. [ABSTRACT FROM AUTHOR]

In this work, a new type of multicomponent nanostructures is introduced by forming interpenetrating networks of two different nanomaterials. In detail, gel networks from semiconductor nanorods are interpenetrated by Au nanowires. Two different types of gelling agents, namely S2− and Yb3+, are employed to trigger the network formation. The structural and electrochemical properties of the resulting materials are discussed. (Photo)electrochemical measurements are performed on the structures to compare the materials in terms of their conductivity as well as their efficiency in converting photonic energy to electrical energy. The new type of CdSe/CdS:Au nanostructure gelled with S2− shows one order of magnitude higher photocurrent than the system gelled with Yb3+. Moreover, the introduction of Au nanowires exhibit a photocurrent which is two orders of magnitudes higher than in samples without Au nanowires. [ABSTRACT FROM AUTHOR]

A hybrid cadmium sulfide nanoparticles (CdSNPs) electroluminescence (EL) device was fabricated by Phase – Segregated Method and characterized. It was fabricated as layers of (ITO/poly-TPD:CdS ) and (ITO/poly-TPD:CdS /Alq3). PolyTPD is an excellent Hole Transport Layer (HTL), CdSNPs is an emitting layer and Alq3 as electron transport layer (ETL). The EL of Organic-Inorganic Light Emitting Diode (OILED) was studied at room temperature at 26V. This was achieved according to band-to-band transition in CdSNPs. From the I-V curve behavior, the addition of Alq3 layer decreased the transfer of electrons by about 250 times. The IV behavior for (poly-TPD/CdS) is exponential with a maximum current of 4500 µA. While, the current is constant for (poly-TPD:CdS /Alq3) and the maximum current was 16.5 µA. Semiconductor nanoparticles like CdS are attractive for fabricating hybrid LEDs with spectrally pure color, low operating voltage values, and shortwavelength electro-luminescence, needed for the RGB devices. The correlated color temperature (CCT) was equal to (1700 oK) for the emitted blue light. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Emerging engineering strategies of colloidal metal‐semiconductor nanorod hybrid nanostructures spanning from type, size, dimension, and location of both metal nanoparticles and semiconductors, co‐catalyst, band gap structure, surface ligand to hole scavenger are elaborated symmetrically to rationalize the design of this type of intriguing materials for efficient photocatalytic applications. [ABSTRACT FROM AUTHOR]

Metal oxide semiconductor (MOS) gas sensing materials have high operating temperatures and often use rigid materials as substrates, making them difficult to be widely applied in the field of wearable electronic devices. In this work, the sheath-core structure electrospun nanofiber core-spun yarn (ES-PY) was prepared using the coaxial electrospun yarn technology, and then the poly (dopamine) was polymerized on its surface to obtain the poly (dopamine) nanofiber core-spun yarn (PDA-PY). ZnO/SnO 2 /Mn metal oxide semiconductor nanoparticles (ZS/Mn-NPs) were synthesized via a two-step hydrothermal process by doping Mn into ZnO/SnO 2. These were subsequently loaded onto the surface of PDA-PY to produce the yarn sensor (ZS/Mn-PY).The combination of the nano-size effect of the nanofibers and the doping-promoting effect of the Mn-doped metal oxide semiconductor further increases the adsorption sites of the gas molecules so that the sensor exhibits excellent gas sensitivity to ammonia (NH 3), with a response up to 13.13 (R a /R g) in an ammonia atmosphere at a concentration of 100 ppm, and still up to 2.61 when exposed to an ammonia atmosphere at a concentration as low as 10 ppm at room temperature. In addition, it retains the excellent flexibility and strength of the core yarn. And provides a simple and effective method for preparing flexible textile gas sensor. [ABSTRACT FROM AUTHOR]

With the growing concerns about the conservation of the environment and the minimal consumption of water, the self-cleaning approach for textile materials is gaining much popularity and interest day-by-day. There are various approaches for producing self-cleaning textiles surfaces, of which the application of nanoparticles is more effective. The self-cleaning property can be achieved by either creating super-hydrophobic surfaces or applying photocatalyst materials. Super-hydrophobic self-cleaning surface follows the principle of the behavior of liquid on surface roughness. On the contrary, under the exposure of light radiation, the photocatalytic self-cleaning surface follows the chemical redox reaction mechanisms to degrade the organic materials including microorganisms or stains. Several previous studies were done to implement self-cleaning functionality to textile materials. Hierarchical surface roughness using nano-whisker or nano-spherical structure using SiO2, carbon nanotubes or ZnO nanoflower produces super-hydrophobic self-cleaning surface with excellent water contact angle whereas different semiconductor nanoparticles including TiO2, ZnO, SnO2 exhibit photocatalytic properties. There are various suggested methods of synthesis and fabrication methods to impart nanoparticles on textile materials. In this review paper, the progress and technological advances in the field of nanoparticles impregnated self-cleaning textiles materials are discussed with different fabrication methods and nanoparticles. Apart from various challenges and limitations, nanoparticles coated self-cleaning textile materials have a wide range of applications in different fields. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Emerging engineering strategies of colloidal metal‐semiconductor nanorod hybrid nanostructures spanning from type, size, dimension, and location of both metal nanoparticles and semiconductors, co‐catalyst, band gap structure, surface ligand to hole scavenger are elaborated symmetrically to rationalize the design of this type of intriguing materials for efficient photocatalytic applications. [ABSTRACT FROM AUTHOR]

Alkanes such as n‐hexane have been used as co‐solvents in the production of functionalized semiconductor nanoparticles from alkenes and alkynes using Reactive High Energy Ball Milling (RHEBM) under the assumption that they are non‐reactive under typical milling conditions. In this paper, a comparative study with two hydrocarbon solvents of comparable chain length, 1‐hexyne, and n‐hexane, and their milling products using three different commercially available silicon precursors, namely single crystal silicon wafers and polycrystalline particles having a nominal size of 4 µm and 1 mm, is reported. It is found that nanoparticle formation and surface functionalization in all the three silicon systems occurs only with 1‐hexyne; n‐hexane is non‐reactive and does not lead to appreciable functionalized nanoparticle formation under the conditions studied. Nanoparticles (where formed) and microparticle byproducts of appropriate samples are characterized by Transmission electronic microscope (TEM), Fourier transform infrared (FTIR), Photoluminiscence spectroscopy (PL), Nuclear magnetic resonance 1H/13C NMR, and thermogravimetry TGA to separately confirm nanoparticle formation and surface functionalization. [ABSTRACT FROM AUTHOR]

This research group evaluated the bondability of sinter bonding using Ni nanoparticles, which have a high melting point and excellent corrosion resistance, as a new metal nanoparticle bonding material, and found that bonding is possible at bonding temperatures below 400 °C when the particle size is less than 100 nm. Furthermore it was found that Ni nanoparticles can be directly bonded to Al, which is considered difficult to bond directly with solder materials containing tin (Sn) or lead (Pb), and that high bonding strength can be obtained. In addition, the bonding strength of Ni nanoparticles to Al was higher when bonded in air than in a reduction atmosphere of N2+H2 (3%), indicating that there were differences in bonding properties depending on the bonding atmosphere. In this study, we compared the bonding properties to Al in different bonding atmospheres. In the N2+H2 (3%) reducing atmosphere, the bonding strength was not increased even when the bonding temperature was increased. On the other hand, the bonding strength was significantly increased with increasing bonding temperature over 330 °C in air. The failure mode was also rupture in the bonding layer, and good bonding was achieved at the Ni/Al bonding interface. Observation of the bonding interface between Ni nanoparticles and Al using Transmission electron microscope (TEM) showed the presence of an interlayer of oxide film at both bonding interfaces in air and in the N2+H2 (3%) reduction atmosphere. And the oxide layer at the interface bonded in air was thicker, indicating that the structure at the interface between the Ni layer, the oxide layer and the Al layer has changed. It was suggested that the difference in oxide film formation behavior, structure, and thickness affects the bondability due to the difference in the bonding atmosphere. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) are widely investigated in the field of optoelectronics due to their various unique spectral and excellent fluorescence properties. However, QDs suffer from intermittent fluorescence, also known as blinking, that limits their use in optoelectronic devices. The blinking mechanism can be suppressed by numerous processes, and one such process includes the interaction of the QDs with semiconductor nanoparticles (NPs) such as indium tin oxide (ITO) and titanium dioxide ( TiO 2). By encapsulating the QDs in these NPs, the blinking rate is significantly reduced due to the electron transfer pathway between them. The interaction of QDs with metal NPs such as silver (Ag) and gold (Au) also greatly enhances the fluorescence behavior due to energy transfer and plasmonic effects. This work deals with the electron transfer model that analyzes the effect of radiative recombination, non-radiative recombination, and electron transfer between QDs and the NPs. An analysis of the on and off states for QDs under the influence of considered NPs has also been done. The on and off time for QDs have also been studied, which provide a comprehensive framework of the performance of the QDs interfaced with these NPs. A comparison between the QDs interacting with glass and other semiconductor and metal NPs is also drawn to compare the efficacy of QDs under the influence of different NPs. This analysis postulates the physical mechanism for blinking and ways to curb these mechanisms using the semiconductor and metal NPs. The theoretical study demonstrates the quantitative insights and prerequisites for designing QD-based optoelectronic devices. [ABSTRACT FROM AUTHOR]

The production of reactive oxygen species (ROS), such as hydroxyl radicals, by ultrasonic activation of semiconductor nanoparticles (NPs), including TiO2, has excellent potential for use in sonodynamic therapy and for the sonocatalytic degradation of pollutants. However, TiO2 NPs have limitations including low yields of generated ROS that result from fast electron–hole recombination. In this study, we first investigated the sonocatalytic activity of TiO2-supported Au nanoclusters (NCs) (Au NCs/TiO2) by monitoring the production of hydroxyl radicals (•OH) under ultrasonication conditions. The deposition of Au144 NCs on TiO2 NPs was found to enhance sonocatalytic activity for •OH production by approximately a factor of 2. Electron–hole recombination in ultrasonically excited TiO2 NPs is suppressed by Au144 NCs acting as an electron trap; this charge separation resulted in enhanced •OH production. In contrast, the deposition of Au25 NCs on TiO2 NPs resulted in lower sonocatalytic activity due to less charge separation, which highlights the effectiveness of combining Au144 NCs with TiO2 NPs for enhancing sonocatalytic activity. The sonocatalytic action that forms electron–hole pairs on the Au144/TiO2 catalyst is due to both heat and sonoluminescence from the implosive collapse of cavitation bubbles. Consequently, the ultrasonically excited Au144 (3 wt. %)/TiO2 catalyst exhibited higher catalytic activity for the production of •OH because of less light shadowing effect, in contrast to the lower catalytic activity when irradiated with only external light. [ABSTRACT FROM AUTHOR]

The nematic phase of the bent-core family proves to be particularly fascinating due to its distinct properties in comparison to its calamitic counterpart. Here we revealed after the dispersion of semiconducting CdS QD an achiral unsymmetrical (4′-fluoro phenyl azo) phenyl-4-yl 3-[N-(4′-n-hecyloxy two hydroxybenzylidene)amino]-2-methylbenzoate (6-2M-F) a bent-core nematic (BCN) liquid-crystalline medium made of bent-shaped molecules with short cores and low bend angles. These molecules are on the cusp between conventional bent-core molecules and rod-like molecules, with characteristics somewhere in between, resembling hockey sticks. The threshold voltage (V th) , dielectric permittivity (ε ‖ , ε ⊥) , and elastic constants (K 33 , K 11) of pure BCN have been considerably influenced by semiconductor nanoparticles. The threshold voltage (V th) of nano-disperse BCN has decreased with QD doping, and we know that the low operation voltage is one of the key considerations in the development of mobile liquid crystal display technology. Similar to other BCNs with smectic-like clusters previously described, the elastic anisotropy (Δ K = K 33 − K 11) for 6-2M-F is negative; however, the insertion of CdS QDs causes the anisotropy to become very positive (bend elastic constant (K 33) > splay elastic constant (K 11)). While the parallel component of permittivity (ε ‖) has declined with doping, the perpendicular component of permittivity (ε ⊥) has increased, leading to a considerable reduction in dielectric anisotropy (Δ ε = ε ‖ − ε ⊥) in the nanocomposite, which implies the effect on nematic ordering due to the interaction between CdS QDs and the LC molecules. [ABSTRACT FROM AUTHOR]

Manganese-doped cadmium sulphide semiconductor nanoparticles (CdS: Mn) NPs have been created utilizing a microwave-assisted solvothermal technique at different Mn concentrations (0, 1%, 3%, and 5%). The chemicals utilized for the preparation of Mndoped CdS nanoparticles were sodium sulphide (Na2S.xH2O), manganese chloride (MnCl2.4H2O), and cadmium acetate (CH3COO)2Cd., H2O). To determine the structural dimensions of the generated nanoparticles, the Debye-Scherer equation was used to calculate the average crystallite size at the full-width half maximum (FWHM) of the diffraction peaks. FTIR spectra analysis was used to look at the various functional and vibrational groups present in the Mn-doped CdS nanoparticle sample. The structure features of the produced nanoparticles have been examined using X-ray diffraction patterns. Energy dispersive X-rays were employed to ascertain the chemical composition of the synthesized nanoparticles. The optical properties and quantification of the energy band gap of the nanoparticles have been done using UV-V spectroscopy. According to XRD calculations, the cubic zinc-blend structure of the generated NPs had a crystal size of between 4 and 7 nm. By using EDX spectroscopy, the incorporation of Mn at the CdS lattice was confirmed. [ABSTRACT FROM AUTHOR]

In this work, the photocatalytic activity of nanoparticles (NPs) of zinc oxide synthetized by Prosopis laevigata as a stabilizing agent was evaluated in the degradation of methylene blue (MB) dye under UV radiation. The theoretical study of the photocatalytic degradation process was carried out by a Langmuir–Hinshelwood–Hougen–Watson (LHHW) model. Zinc oxide nanoparticles were synthesized by varying the concentration of natural extract of Prosopis laevigata from 1, 2, and 4% (weight/volume), identifying the samples as ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. The characterization of the nanoparticles was carried out by Fourier transform infrared spectroscopy (FT-IR), where the absorption band for the Zn-O vibration at 400 cm−1 was presented; by ultraviolet–visible spectroscopy (UV–vis) the value of the band gap was calculated, resulting in 2.80, 2.74 and 2.63 eV for the samples ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively; XRD analysis indicated that the nanoparticles have a hexagonal zincite crystal structure with an average crystal size of 55, 50, and 49 in the sample ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. The morphology observed by TEM showed that the nanoparticles had a hemispherical shape, and the ZnO_PL4% sample presented sizes ranging between 29 and 45 nm. The photocatalytic study showed a total degradation of the MB in 150, 120, and 60 min for the samples ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. Also, the model explains the experimental observation of the first-order kinetic model in the limit of low concentrations of dye, indicating the influence of the mass transfer processes. [ABSTRACT FROM AUTHOR]

To gain insight into the applicability as building blocks for optoelectronic device development, alkaline earth metal sulfides are investigated. MgS, CaS, SrS, and BaS have been systematically synthesized as colloidal particles in olelyamine. The particle sizes range from around 819 nm for MgS to 12.8 nm for CaS, 25.0 nm for SrS, and 21.6 nm for BaS. The heat-up synthesis uses commerically available precursors without complicated procedures. The structural and optical properties are investigated with X-ray diffraction, spectroscopic ellipsometry, UV–vis spectrophotometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. [ABSTRACT FROM AUTHOR]

Copper indium disulfide nanoparticles continue attracting attention as absorber material in light harvesting devices. The preparation of thin films by deposition of this material from colloidal solution remains challenging. Typically, colloidal semiconductor nanoparticles are surrounded by long organic ligand molecules which are required to stabilize the particles during synthesis. A common way to obtain conductive thin films is the development of ligand exchange procedures that need to be applied prior to film deposition. However, in the case of copper indium disulfide nanoparticles, appropriate procedures are still missing. Therefore, an alternative approach is investigated herein. Colloidal copper indium disulfide nanoparticles are synthesized and deposited on substrates. Instead of applying a ligand exchange procedure, thermal removal of the ligands and sintering of the inorganic film are explored. Results on the preparation of the nanoparticle films, their structural investigation, and conductivity measurements are reported. [ABSTRACT FROM AUTHOR]

This paper reports on a simple and efficient process to obtain semiconductor zinc oxide (ZnO) nanoparticles (NPs) using Artemisia ludoviciana extract as a chelating agent. The properties of the ZnO NPs were analyzed using various characterization techniques, revealing hexagonal and quasi-spherical NPs with sizes going from 30.46 to 16.74 nm and band gap values of 2.5 to 2.2 eV. Additionally, the structural analysis shows a wurtzite phase with no secondary phases, while elemental analysis revealed both the presence of residual carbon from Artemisia ludoviciana and the presence of oxygen vacancies. The photocatalytic assay of the obtained ZnO showed excellent methyl orange (MO) degradation. The best performance was observed with E4, which removed 95.8% of MO after being exposed to UV light for 120 min. The results demonstrate that the ZnO NPs obtained using Artemisia ludoviciana have good photocatalytic capabilities and show potential to be used in other similar applications. [ABSTRACT FROM AUTHOR]

One of the important molecules in homeostasis, especially for hormone metabolism, cellular membrane production, and vitamin D synthesis is cholesterol. However, studies showed that increased levels of this molecule would be associated with increased incidence of cardiovascular diseases including heart failure and myocardial infarction (MI). Thus, the measurement of the blood level of cholesterol is an important step for early detection and prevention of several diseases. Electrochemical sensors with high accuracy could be useful for the detection of cholesterol in body fluids. Due to the outstanding chemical and physical properties that nanoparticles possess, they are perfectly suited for the development of new and improved sensing devices. In particular, electrochemical sensors and biosensors are two types of sensing devices that could benefit from the use of nanoparticles. Many different kinds of nanoparticles, such as metal nanoparticles, oxide nanoparticles, semiconductor nanoparticles, and even composite nanoparticles, have found widespread application in electrochemical sensors and biosensors, respectively. This review has covered a variety of electrochemical biosensors for cholesterol detection, including conductometric, amperometric, and potentiometric-based biosensors, as well as their detection techniques and limitations. [ABSTRACT FROM AUTHOR]

The synthesis of TiO2 nanoparticles (NPs) in supercritical media has been reported over the last two decades. However, very few studies have compared the physicochemical characteristics and photoactivity of the TiO2 powders produced from different precursors, and even fewer have investigated the effect of using different ratios of hydrolytic agent/precursor (HA/P) on the properties of the semiconductor. To bridge this knowledge gap, this research focuses on the synthesis and characterization of TiO2 NPs obtained in a supercritical CO2 medium from four different TiO2 precursors, namely diisopropoxytitanium bis (acetylacetonate) (TDB), titanium (IV) isopropoxide (TIP), titanium (IV) butoxide (TBO), and titanium (IV) 2-ethylhexyloxide (TEO). Further, the effect of various HA/P ratios (10, 20, 30, and 40 mol/mol) when using ethanol as a hydrolytic agent has also been analyzed. Results obtained have shown that the physicochemical properties of the catalysts are not significantly affected by these variables, although some differences do exist between the synthesized materials and their catalytic performances. Specifically, photocatalysts obtained from TIP and TEO at the higher HA/P ratios (HA/P = 30 and HA/P = 40) led to higher CO2 photoconversions (6.3–7 µmol·g−1·h−1, Apparent Quantum Efficiency < 0.1%), about three times higher than those attained with commercial TiO2 P-25. These results have been imputed to the fact that these catalysts exhibit appropriate values of crystal size, surface area, light absorption, and charge transfer properties. [ABSTRACT FROM AUTHOR]

Nowadays, carbon quantum dots (CDs) as semiconductor synthesized nanoparticles have become an attractive subject for lots of applications due to their remarkable features. In the current study, the highly fluorescent (FL) CDs with great characteristics were synthesized through a novel one-step microwave irradiation by citric acid monohydrate and urea as carbon precursors. The as-prepared CDs were quasi-spherical shape with an average diameter of 4.5 nm and emitted bright blue FL under ultraviolet light irradiation (UV). Furthermore, the synthesized CDs possessed different properties such as diverse functional groups, good sensitivity and selectivity, high water-solubility, low toxicity, and significant stability in various environmental conditions. The results indicated that the as-prepared CDs can be applied as a fluorescent probe for detection of different concentrations of tartrazine from 5 to 100 µM in food samples. In addition, the findings revealed that the good linear relationship was obtained between the FL intensity of CDs and different concentrations of tartrazine over the range of 5 to 100 µM with the detection limit of 2.58 µM. [ABSTRACT FROM AUTHOR]

Semiconductor nanoparticles (NPs) are attractive for use as the constituent blocks of artificial solids. Furthermore, the layer-by-layer (LbL) method allows one to accurately arrange and stack NPs and is being explored widely for the fundamental research and development of artificial solids and devices based on NPs. In this study, we determined the absolute values of the dielectric function of monolayered semiconductor NPs deposited by the LbL method. The aim was to measure the structural parameters, such as the thickness, NP volume density, and NP number density, of the monolayered films composed of NPs. A novel fully optical method based on spectroscopic ellipsometry was used to evaluate thin films composed of monolayered CdS NPs deposited by the LbL method. We could successfully determine the absolute values of the dielectric function of the CdS NPs deposited as monolayered films based on the above-listed parameters with accuracy. Thus, the optical constants of monolayered semiconductor NPs as well as their structural information could be obtained successfully using the proposed method, which is highly suited for nondestructively determining the parameters of thin films, including those of semiconductor NPs. [ABSTRACT FROM AUTHOR]

We use excited-state quantum chemistry techniques to investigate the intraband absorption of doped semiconductor nanoparticles as a function of doping density, nanoparticle radius, and material properties. Modeling the excess electrons as interacting electrons confined to a sphere, we find that the excitation evolves from single-particle to plasmonic with increasing number of electrons at fixed density, and the threshold number of electrons to produce a plasmon increases with density due to quantum confinement and electron–hole attraction. In addition, the excitation passes through an intermediate regime where it is best characterized as an intraband exciton. We compare equation-of-motion coupled-cluster theory with those of more affordable single-excitation theories and identify the inclusion of electron–hole interactions as essential to describing the evolution of the excitation. Despite the simplicity of our model, the results are in reasonable agreement with the experimental spectra of doped ZnO nanoparticles at a doping density of 1.4 × 1020 cm−3. Based on our quantum chemistry calculations, we develop a schematic model that captures the dependence of the excitation energy on nanoparticle radius and electron density. [ABSTRACT FROM AUTHOR]

We model the enhancement of near band edge emission from ZnO nanorods using plasmonic metal nanoparticles and compare it with emission enhancement from ZnO with semiconducting quantum dots. Selected CdSe quantum dots with absorption energies close to those of Ag and Au nanoparticles are chosen to construct model systems with ZnO to comprehend the role of ZnO's intrinsic defects and plasmonic excitation in realizing the spectrally selective luminescence enhancement. Excitation wavelength dependent photoluminescence spectra along with theoretical models quantifying the related transitions and plasmonic absorption reveal that a complex mechanism of charge transfer between the ZnO nanorods and metal nanoparticles or quantum dots is essential along with an optimal energy band alignment for realizing emission enhancement. The theoretical model presented also provides a direct method of quantifying the relative transition rate constants associated with various electronic transitions in ZnO and their change upon the incorporation of plasmonic nanoparticles. The results indicate that, while the presence of deep level defect states may facilitate the essential charge transfer process between ZnO and the plasmonic nanoparticles, their presence alone does not guarantee UV emission enhancement and strong plasmonic coupling between the two systems. The results offer clues to designing novel multicomponent systems with coupled plasmonic and charge transfer effects for applications in charge localization, energy harvesting, and luminescence enhancement, especially in electrically triggered nanophotonic applications. [ABSTRACT FROM AUTHOR]

Localized surface plasmon resonances (LSPRs) are gaining considerable attention due to the unique far-field and near-field optical properties and applications. Additionally, the Fermi energy, which is the chemical potential, of plasmonic nanoparticles is one of the key properties to control hot-electron and -hole transfer at the interface between plasmonic nanoparticles and a semiconductor. In this article, we tried to control the diffusion potential of the plasmonic system by manipulating the interface dipole. We fabricated solid-state photoelectric conversion devices in which gold nanoparticles (Au-NPs) are located between strontium titanate (SrTiO3) as an electron transfer material and nickel oxide (NiO) as a hole transport material. Lanthanum aluminate as an interface dipole layer was deposited on the atomic layer scale at the three-phase interface of Au-NPs, SrTiO3, and NiO, and the effect was investigated by photoelectric measurements. Importantly, the diffusion potential between the plasmonic metal and a semiconductor can be arbitrarily controlled by the averaged thickness and direction of the interface dipole layer. The insertion of an only one unit cell (uc) interface dipole layer, whose thickness was less than 0.5 nm, dramatically controlled the diffusion potential formed between the plasmonic nanoparticles and surrounding media. This is a new methodology to control the plasmonic potential without applying external stimuli, such as an applied potential or photoirradiation, and without changing the base materials. In particular, it is very beneficial for plasmonic devices in that the interface dipole has the ability not only to decrease but also to increase the open-circuit voltage on the order of several hundreds of millivolts. [ABSTRACT FROM AUTHOR]

Sarcoidosis is a complex inflammatory multisystem disease of unknown etiology that is characterised by epithelioid cell granulomatous lesions affecting various organs, mainly the lungs. In general, sarcoidosis is asymptomatic, but some cases result in severe complications and organ failure. So far, no accurate and validated modelling for clinical and pathohistological manifestations of sarcoidosis is suggested. Moreover, knowledge about disease-specific diagnostic markers for sarcoidosis is scarce. For instance, pulmonary granulomatosis is associated with the upregulated production of proinflammatory molecules: TNF-α, IL-6, CXCL1, CCL2, CCL18, CD163, serum angiotensin-converting enzyme (sACE), lysozyme, neopterin, and serum amyloid A (SAA). Quantum dots (QDs) are widely applied for molecular diagnostics of various diseases. QDs are semiconductor nanoparticles of a few nanometres in size, made from ZnS, CdS, ZnSe, etc., with unique physical and chemical properties that are useful for the labelling and detection in biological experiments. QDs can conjugate with various antibodies or oligonucleotides, allowing for high-sensitivity detection of various targets in organs and cells. Our review describes existing experimental models for sarcoidosis (in vitro, in vivo, and in silico), their advantages and restrictions, as well as the physical properties of quantum dots and their potential applications in the molecular diagnostics of sarcoidosis. The most promising experimental models include mice with TSC2 deletion and an in silico multiscale computational model of sarcoidosis (SarcoidSim), developed using transcriptomics and flow cytometry of human sarcoid biopsies. Both models are most efficient to test different candidate drugs for sarcoidosis. [ABSTRACT FROM AUTHOR]