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Abstract We report the fabrication and characterization of a Bi(III) oxide/polypyrrole (Bi2O3/Ppy) nanocomposite thin film optoelectronic photodetector synthesized by a simple one-pot method. The nanocomposite consists of spherical Bi2O3 nanoparticles embedded in a Ppy matrix, forming a porous structure with a high surface area. The XRD analysis reveals that the Bi2O3 nanoparticles have a poly-crystalline nature with a crystal size of 40 nm and an optical bandgap of 2.86 eV. The SEM images show that the nanoparticles are agglomerated into clusters of about 100 nm in diameter, with pores of about 200 nm in width. The device exhibits a high sensitivity to light, as evidenced by the increase of the photocurrent density (Jph) from − 0.06 mA.cm−2 in the dark to -0.12 mA.cm−2 under illumination at -2.0 V. The device also shows a wavelength-dependent response, with the highest responsivity (R) of 1.0 and 0.9 mA/W and detectivity (D) of 0.221 × 109 and 0.20 × 109 Jones at photon energies of 3.6 eV and 2.8 eV, respectively. The Bi2O3/Ppy nanocomposite is a promising material for low-cost, high-performance optoelectronic applications, making it a superior choice over many contemporary devices reported in recent literature.

Abstract A polypyrrole-bismuth tungstate (Ppy-Bi2WO6) core-shell nanocomposite (n-type material) has been developed on a layered Ppy (p-type) base as an efficient light-capturing material exhibiting photodiode behavior. This device demonstrates promising sensitivity for light sensing and captures across a broad spectral range, from near IR to UV. The Bi2WO6/Ppy nanocomposite boasts an optimal bandgap of 2.0 eV, compared to 3.4 eV for Ppy and 2.5 eV for Bi2WO6. The crystalline size of the core-shell composite is approximately 21 nm, emphasizing its photon absorption capabilities. The composite particles, around 100 nm in length, feature a highly porous morphology that effectively traps incident photons. The performance of this optoelectronic device is evaluated using current density (J) measurements under light (Jph) and dark (Jo) conditions. In darkness, the n-p type semiconductor exhibits limited current with a Jo of −0.22 mA cm−2 at 2.0 V. When exposed to white light, the Ppy- Bi2WO6/Ppy device generates hot electrons, achieving a Jph value of 1.1 mA/cm−2 at 2.0 V. It shows a superior responsivity (R) of 6.6 mA/W at 340 nm, gradually decreasing to 6.3 mA/W at 440 nm and 4.2 mA/W at 540 nm, indicating high sensitivity across the UV-Vis spectrum. At 730 nm, the R-value is 2.6 mA/W, highlighting its sensitivity in the near IR region. Additionally, at 340 nm, the device achieves a detectivity (D) value of 0.15 × 10¹⁰ Jones, which decreases with longer wavelengths to 0.14 × 10¹⁰ Jones at 440 nm, 0.9 × 10⁹ Jones at 540 nm, and 0.63 × 10⁹ Jones at 730 nm. With its great stability, low cost, easy fabrication, and potential for mass production, this optoelectronic light sensor and photodiode device holds significant promise for industrial applications as a highly effective optoelectronic device.

Abstract A nanocomposite with a unique satellite dish-like structure, termed arsenic (III) oxide iodide (AsO2I)/polypyrrole (Ppy) intercalated with iodide ions (AsO2I/Ppy-I), has been meticulously developed via a two-step process. It features natural satellite dish-like nanostructures, potentially serving as nanoresonators for efficient single photon absorption. With a bandgap of 2.8 eV, the AsO2I/Ppy-I nanocomposite efficiently absorbs photons in the UV and visible light regions, making it suitable for single photon detection. Impressive performance is seen in photocurrent sensitivity measurements, recording values of 0.017 mA.cm−2 under white light and 0.009 mA.cm−2 under monochromatic light at 340 nm. Additionally, it exhibits high responsivity and detectivity, with peak values at wavelengths of 340 nm and 440 nm associated with the diameter of the Satellite dish nanostructure. Cost-effectiveness and simple synthesis methods make it attractive for industrial applications, while its unique structural characteristics and enhanced optical properties position it as a valuable asset in optoelectronic technologies. It holds promise as a leading material in advanced quantum technology, marking a significant leap forward in optoelectronic technologies, with potential applications in quantum cryptography, communication, and computing.

Improving solar cell performance hinges significantly on the application of anti-reflective surface coatings. A wide variety of coating techniques, including blade coating, spin coating, dip coating, and others were employed. The present research investigation employed various coating materials, namely SiO2 (Silicon dioxide), ZrO2 (Zirconium dioxide), and SiO2–ZrO2 blends, to apply a protective layer onto polycrystalline silicon solar cells using the sputter coating process. The efficiency of these solar cells with multilayer coating was assessed through diverse characterization methods. The uniform thin films were obtained using a 45-min coating process using an input voltage source of 17 kV, which was confirmed through analyses conducted using FESEM and AFM techniques. The UV–Vis spectroscopy and current-voltage source metre were employed to examine the light absorption and transmittance of bare and coated silicon solar cells. When compared to alternative solar cells, the solar cell coated with a combination of SiO2 and ZrO2 demonstrated uniform deposition and a low light reflectance of only 6 %. SiO2–ZrO2 gains a highest power conversion efficiency (PCE) of 17.6 % under controlled light source. This superior performance was due to the increase in photon transmittance in to the depletion region. Furthermore, the electrical resistivity of the SiO2–ZrO2 blend coated solar cell was measured using the four-probe method was found to be 2.89 × 10−3 Ω-cm, which was lower than that of other solar cells. From the experimental results, it was clear that SiO2 - ZrO2 blend-coated solar cells outperformed both other coated and uncoated solar cells. Consequently, SiO2–ZrO2 blends emerged as superior anti-reflective materials for achieving peak performance.

This study involved the preparation of novel samples of polypyrrole-doped carbon/polyvinyl alcohol/lithium titanate nanocomposites, PPY-C/PVA/LiO, with a tuning of LiO concentration using the casting technique to be applicable in different applications. Various analytical procedures were employed to examine their optical, morphological, structural, and electrical properties. It was decided that the PPY-C/PVA is an amorphous structure that became crystalline when LiO NPs were added. This happened because the functional groups of the PPY-C/PVA and LiO NPs interacted with each other. It confirmed that by appearing the new characteristic diffraction peaks of LiO and the new vibrational stretching peak at 588 cm−1 of the metal-O bond and deducing the uniform distribution of the blend matrix with an increase in the number of white dots, it served as evidence of the impact of surface roughness on tuning the electrical properties of the nanocomposite. Also, studies on conductivity showed that as the concentration of LiO goes up, AC conductivity, dielectric constant, and dielectric loss all go down. This is because more nanofiller is added, more immobile ions form in clumped areas, and dipole polarization goes down. Also, adding LiO NPs to the polymeric matrix makes the matrix's chains less flexible, which raises the crystallinity ratio. The obtained results suggest that the prepared PPY-C/PVA/LiO nanocomposite is promising candidates in the fabrication of nano-electronic devices.

Wide bandgap semiconductors such as Zinc Oxide (ZnO) have earned much attention on account of its interesting optical and electrical properties. Also, doping ZnO with suitable transition elements enables to tune its properties, making it suitable for applications like transparent conducting oxides and LEDs. To this aim, Vanadium-doped ZnO (V:ZnO) thin films are fabricated using the SILAR method and studied the structural, optical, vibrational, photophysical and electrical properties. Introducing vanadium creates lattice relaxation in the ZnO wurtzite structure, influencing its electronic band structure. The X-ray diffraction (XRD) analyses have verified the structural integrity of the vanadium-doped zinc oxide (V:ZnO) films, revealing their polycrystalline composition. The Raman spectroscopy shows the reduced phonon line widths due to the improved crystallite quality with the presence of vanadium. Furthermore, it has been noted that optical characteristics such as the bandgap and refractive index are sensitive to vanadium doping as a consequence of modified electronic structures. Hall-effect experiments have shown that undoped ZnO films possess a mobility of 1.31 cm2/Vs and a charge carrier density of 5.58 × 1013 cm−3. It has been observed that doping with V markedly influences these parameters of ZnO films. Then, the time-resolved photoluminescence measurements reveal the increased carrier lifetimes, suggesting the introduction of dopants mitigates carrier-phonon interactions. Such interactions need to be minimized to prevent the dissipation of carrier energy. In essence, the reported work demonstrates the potential of V:ZnO for optoelectronic applications.

Spinel Li4Ti5O12 (LTO) is a potential anode material for innovative high-power lithium-ion batteries (LIBs) because of its ''zero strain'' features during quick charging/discharging, extended cycle life, and elevated rate capability. However, LTO has limited application due to its poor ionic/electronic conductivity and slow ionic diffusion coefficient. In this work, LTO/polyether sulfone (PES) composite is synthesized via pulsed laser ablation in liquid media technique based on an infrared Nd:YAG nanosecond laser. The influences of laser ablation power were used to vary the particle sizes of the generated LTO nanoparticles on the formation of the LTO/PES structure, followed by the electrochemical performances of LTO. Various methods were used to investigate the composite's structural, optical, and morphological properties. The interactions between the polymer and nanoparticles, as well as the fine dispersion of NPs, were evident in the optical tests, which showed that the absorbance greatly improved and the energy band gap decreased. Also, the morphological images display the cubic shape of pure LTO NPs with varying particle sizes between 5 and 26 nm as the laser power changes. Furthermore, from XRD characterization, the intensity of this crystalline peak of PES decreases as a function of LTO wt. % increase without appearing of any other impurities. After that, the electrochemical performances were tested for all prepared samples, which showed that the as-prepared composite structure with a lower particle size exhibits excellent electrochemical performances. This result demonstrates that providing surface defects by forming Ti3+/Ti4+ pairs and oxygen vacancies in LTO is a successful method for increasing ion/electron mobility. This method can be applied to improve the battery efficiency of other substances with low ionic conductivities in the developed batteries.

Polymer nanocomposites based on recycled polystyrene (PS) and polyvinylpyrrolidone (PVP) with various reduced graphene oxide (rGO) loadings were prepared through a facile casting technique for enhancing the electrical conductivity of the insulator waste polystyrene to be applicable in electronic devices. The prepared nanocomposites were investigated by different techniques. FTIR analysis shows a reduction and shift of the main vibrational peaks of the blend, which confirms the introduction of (rGO) to the polymeric matrix, while XRD diffractograms provide complementary evidence for the transformation of graphene oxide into (rGO). The SEM image of the fractured edge of the sample points to a homogenous distribution of the PVP inside the major phase of the PS matrix. Moreover, the TEM image shows graphene oxide nanoparticles appearing in the form of dark lamellar structures with some light dots on a gray background, representing the polymeric domain. Besides, the TGA shows the existence of (rGO) led to some shifts in the PS and PVP onset decomposition temperatures when compared to the reference blend sample. Besides, the conductivity and dielectric properties of the prepared nanocomposites were characterized over a wide frequency range. Introducing (rGO) considerably enhanced their dielectric constant and ionic conductivity. The conductivity of these nanocomposites ranged from 10−11 to 10−6 S/m. The dielectric constant and dielectric loss of these composites were tested through frequencies, 0.1 Hz - 1 MHz, at 30 °C. The obtained values of the dielectric constant, loss tangent, and DC conductivity (σdc) suggested that the prepared nanocomposites could be used in various technological sectors such as energy storage, electronics, anti-static, and electro-static dissipation applications.

The opto-photocatalytic applications of Mn-doped NiO nanoparticles (NPs) are discussed. A facile synthesis of NiO doped with different Mn contents is performed and studied using experimental techniques. The structural properties and microstructural parameters of Mn:NiO NPs were examined by X-ray diffraction patterns. The average crystallite sizes of the pure NiO and 1.0-, 2.5-, 5.0-, 10-wt.% Mn-doped NiO NPs were found to be 25–19 nm by Williamson–Hall plots and 23–18 nm by the Debye–Scherer method. The crystallite size decreases with increasing doping concentration in the NiO host lattice. The optical bandgaps are found to be 3.53, 3.46, 3.39, 3.24, and 3.12 eV for pure NiO and 1.0-, 2.5-, 5.0-, and 10-wt.% Mn:NiO NPs, respectively, using the Kubelka–Munk function. X-ray photoelectron spectroscopy spectra of 2.5-wt.% Mn:NiO NPs were recorded for Mn, Ni, and O to determine the oxidation states. The photocatalytic performances of pure NiO and Mn:NiO NPs are examined. The 2.5-wt.% Mn:NPs exhibit the best photocatalytic performance owing to the greatest activation sites. The mechanism of the photocatalytic decolorization reaction is also investigated. The results demonstrate the high ability of Mn:NiO NPs as photocatalysts for methylene blue dye degradation, with 92% removal.

This research explores the novel photo-response properties of cobalt (Co) doped cadmium sulfide (CdS) thin films developed using a facile and cost-effective spray coating technique. The microstructural parameters were evaluated using XRD patterns and the estimated values of crystallite sizes, lattice strains, dislocation densities and induced stress were found to be in the range of 16.1–25.9 nm, 5.9 × 10−3-3.4 × 10−3, 3.8 × 10−3-1.4 × 10−3 and 3.4–1.9 (GPa) for undoped and Co:CdS films, respectively. The optical band gap energies were found to be 2.369, 2.454, 2.469, and 2.501 eV for undoped, 1 wt. %, 3 wt. %, and 5 wt. % Co: CdS films, respectively using Tauc's plots. The values of extinction coefficient (k) and refractive index (n) were observed in the range of 0.45–0.69 and 2.72–3.05 for as-prepared thin films. Photocurrent (Iph)-applied voltage (V) characteristic of the prepared thin films was measured under visible light condition of low power densities (0.15, 0.25, 0.50, 1.57, 2.50 and 5.0 mW/cm2). A remarkable photosensitivity of 0.165–8.842 × 103 (mW/cm2) at 5.0 mW/cm2 was observed. Saturated surface resistivity of as-prepared thin films was measured for pure CdS, which decreases by increasing Co content. External quantum efficiency (EQE) and Detectivity (DET) were enhanced with Co contents. The values of EQE and DET were found to be 1.0 × 103-2.47 × 1012 and 9.88 × 1012 -2.41 × 1012 for 5.0 wt. % Co: CdS films, respectively at power densities (0.15, 0.25, 0.50, 1.57, 2.50 and 5.0 mW/cm2). Our findings proposed the major role of such prepared films in the fabrication of advanced photodetectors suitable for optoelectronic devices developments.

In this report, an economical spray pyrolysis technique was used to develop pure and 2% of Er, Gd, Pr doped MoO3 thin films. Different characterization techniques were utilized to study the properties of the pure and 2% of Er, Gd, Pr doped MoO3 thin films. The structural XRD analysis revealed monoclinic crystal structure of the MoO3 thin films with high purity and highest crystal size of 59 nm for the Pr doped MoO3 thin film. Furthermore, the lattice constant values increase with the substitution of Er, Gd, Pr dopants in MoO3 thin films. The morphological studies revealed reticulated nano-fibrous mesh morphology for all the samples and tiny rod-shaped protrusions over the surface of Pr doped MoO3 thin film. The optical studies demonstrated lower transparency, small bandgap and important defects. The gas sensing studies established the good response of the Pr doped MoO3 thin film towards the NH3 gas of 1.34 × 104% (250 ppm) with high stability and fast response (54 s) with a recovery time of 12 s. This opens door to our synthesized Pr doped MoO3 thin film materials to be used for the construction of commercial ammonia gas sensors.

The capacity to detect and monitor NH3 in the environment in real time has been established using an ammonia (NH3) sensing material consisting of Cobalt (Co) doped Molybdenum trioxide (MoO3) thin films on glass substrates. With Co doping, the XRD peaks of MoO3 films shifted towards lower angle and increase cell volume in the case of 3% Co doped MoO3 film compared to other samples, depicts the successful Co doping into the host structure. The chain link particles observed for as-fabricated MoO3film increased for Co doped films and obtained maximum particle size for 3% Co doped MoO3 film. In addition, to test the films elemental and optical properties, energy-dispersive X-ray (EDX) and UV spectroscopy were used to analyze the prepared samples. Simultaneously, we established the gas-sensing characteristics of Co-doped MoO3 sensors for NH3 detection at room temperature and attained maximum gas response of 9120 % for 3% Co doped MoO3 film. The sensor with 3%Co doped MoO3 sensing film exhibited faster response and recovery times than sensor with undoped MoO3 film, which is critical for MoO3 sensor practical applications. Furthermore, the ammonia selectivity of the doped MoO3 sensors was found to be remarkable.

Chalcogenide glasses are promising contenders for use in radiation shielding applications because of their remarkable radiation shielding properties, such as transparency and good thermal stability. In the current study, the shielding parameters for gamma rays and neutrons are estimated for different compositions of Se75−x–Te25–Agx (0 ≤ x ≤ 10 mole %) chalcogenide glasses using the Phy-X/PSD online software. We referred to the investigated Se75−x–Te25–Agx (x = 0, 2, 4, 6, 8, and 10 mole %) glasses by coded abbreviations as (STA1, STA2, STA3, STA4, STA5 and STA6 respectively). The linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), effective atomic number (Zeff), effective electron density (Neff), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), energy absorption buildup factor (EABF), and exposure buildup factor (EBF) in the photon energy range of 0.15–15 MeV. The specified energy range (0.015–15 MeV) corresponds to the energies emitted from radioactive sources such as (241Am, 55Fe, 133Ba, 60Co, 109Cd, 131I, 152Eu, 22Na, and 137Cs) which may be used in medical, industrial, and nuclear facilities where workers may frequently be exposed to harmful radiations. In the current work, we investigate shielding materials to protect people from radiation-related harm. Furthermore, the fast neutron removal cross section (FNRCS) is estimated. The findings refer to increasing the Ag content results in an enhancement in the shielding characteristics for the glass under investigation. The lowest Zeff values (36.657–37.465) occur at a photon energy of 0.02 MeV; the Zeff values then increase to reach their maxima (43.259–44.347) at a photon energy of 0.06 MeV. The MFP, TVL, and HVL values decrease with increasing Ag content, especially in the intermediate and high photon energy ranges. The results show low HVL and MFP values compared with those obtained for traditional and commercial glasses, especially in the intermediate and high photon energy ranges. The Zeff values increase as the Ag content increases. The FNRCS values are in the range of 0.083–0.092 cm−1 for the investigated glasses. The FNRCS values of these glasses are higher than those of some commercial glasses. The most performance sample for radiation shielding between the investigated glasses is STA6 corresponds to the higher concentration of Ag.

A highly uniform spherical MoO2-MoO3/polypyrrole core-shell nanocomposite has been successfully synthesized as an optoelectronic photon sensing material, capable of detecting light in the UV, Vis, and IR domains. The nanocomposite is prepared through the oxidation of pyrrole using Na2MoO4, resulting in a uniform spherical morphology that has been confirmed by TEM, theoretical modeling, and SEM analyses. This morphology contributes to its promising optical behavior, characterized by a small bandgap of 1.36 eV. The optoelectronic photosensing capability of the nanocomposite has been evaluated across the UV, Vis, and IR spectra, demonstrating high efficiency. The photoresponsivity R values indicate the ability of the nanocomposite to generate hot electrons in response to incident photons. With an R value of 4.15 mA·W−1 at 440 nm, this optoelectronic device exhibits considerable promise for integration into an advanced technological apparatus. The detection (D) value of 9.30 × 108 Jones at 440 nm further confirms the high sensitivity in the Vis region. The excellent stability of the device can be attributed to the inherent MoO2-MoO3 oxide and Ppy polymer materials. This stability has been demonstrated through reproducibility studies and current-voltage measurements under various optical conditions. The combination of stability, efficiency, and sensitivity makes this optoelectronic device well suited for light sensing applications in both industrial and commercial settings. Its promising performance opens up opportunities for advancements in various fields requiring accurate and reliable light detection.

Undoped and codoped (Eu/Na) ZnO nanocrystals (NCs) were successfully manufactured through an economical sol-gel method. X-ray diffraction (XRD) analysis demonstrated pure hexagonal wurtzite structure without secondary phases for all the samples. The size of the NCs was found to decrease with codoping by Eu3+/Na+ which is related to the existence of strain and stress in the lattice. The dominance of the E2(high) mode in Raman spectra indicates the good crystallinity of the samples. The study from the X-ray photoelectron spectroscopy (XPS) shows the successful insertion of both Eu3+ and Na+ ions into the ZnO lattice and the generation of the zinc and oxygen vacancies (Vo) defects. The band gap energy was reduced and the Urbach energy increased with Na+ content, proving the distortion of the lattice. From the photoluminescence (PL) study, the activation of the Eu3+ ions by Na+ ones was evidenced. Longer PL lifetimes were obtained from Eu3+ ions when they were sensitized by Na+, which may be beneficial to several applications. A process of excitation transfer from both the ZnO host and Na+ sensitizers to the Eu3+ ions was evidenced and discussed. As an application, we tested the performances of the prepared NCs as photocatalysts for Rhodamine B photodegradation under sunlight irradiation. The ZnO NCs codoped with 1% Eu/4% Na displayed the best photodegradation rate with a good stability and a high kinetic rate constant k of 0.021 min−1. The photocatalytic mechanism is discussed in terms of longer radiative recombination from Eu3+ and the generated oxygen vacancies.

This study focused on identifying the effect of the laser wavelengths used in cleaning some manifestation damage appearing in pigments used on archaeological cartonnage preserved in the Egyptian Museum, Egypt. The manifestations of damage appear as mud, resin, color, dust and microbiological damage stains. Lasers were chosen as one of the modern applications that give good results when cleaning the pigment materials without making direct contact with the material. Accordingly, lasers with a wavelength of 532 and 1064 nm were tested to identify their effect on stains caused by pigments and to choose the best one for use in cases similar to those materials in the future. This study was conducted to identify the effect of the selected wavelengths and choose the best ones to apply to the archaeological model. The evaluations were conducted using several tests and analyses, such as digital microscopy, X-ray florescence, Fourier transform infrared spectroscopy, and Handy colorimetry to evaluate that effect of lasers with a wavelength of 532 and 1064 nm to remove stains. The experimental study demonstrated the good effect of the Nd:YAG laser with a wavelength of 1064 nm compared with that of the 532 nm laser. The results of using the Nd:YAG laser proved the good effect of removing all stains compared with the 532 nm laser, which caused big changes when used to clean the stains on the pigment’s surfaces; it also did not help in removing or reducing some stains such as mud stains. According to these results, the good effect of the Nd:YAG laser (1064 nm) make it more suitable for cleaning than that of the Nd:YAG laser (532 nm), which is not recommended for use as it gave bad results when applied.

This study explores the effects of Si and Si-P heteroatoms doping and co-doping on a monolayer graphene surface through density functional analysis. The results suggest that doping with Si and co-doping with Si-P significantly alters the bonding arrangement of the atoms surrounding the graphene sheet. Additionally, the surface of the graphene material had a high concentration of electrons in both Si doping and Si-P co-doping, based on electron population analysis. The HOMO–LUMO gap of graphene sheets was found to decrease in the following order: pristine graphene sheet > Si-doped graphene sheet > Si-P co-doped graphene sheet. Furthermore, a TD-DFT study revealed that the absorption wavelength of Si and Si-P co-doped graphene systems had a greater shift to a lower range compared to pristine graphene. The order of decreasing absorption wavelength is Si-P co-doped graphene, Si doped graphene, and pristine graphene. These materials are suggested to have a high potential for photodetector applications due to their broad absorption range.

The high-quality n-type CdS on a p-type Si (111) photodetector device was prepared for the first time by a one-pot method based on an ns laser ablation method in a liquid medium. Cadmium target was ablated in DMSO solution, containing sulfur precursor, and stirred, assisting in 1D-growth, to create the sulfide structure as CdS nano-ropes form, followed by depositing on the Si-substrate by spin coating. The morphological, structural, and optical characteristics of the CdS structure were examined using X-ray diffraction, transmission, and scanning electron microscopy, photoluminescence, and UV-VIS spectroscopy. From X-ray diffraction analysis, the growing CdS spheres have a good crystal nature, with a high purity and desired c-axis orientation along the (002) plane, and the crystallinity was around 30 nm. According to optical characterization, high transparency was found in the visible–near-infrared areas of the electromagnetic spectrum, and the CdS spheres have a direct optical energy band gap of 3.2 eV. After that, the CdS/Si hetero-structured device was found to be improved remarkably after adding CdS. It showed that the forward current is constantly linear, while the dark current is around 4.5 µA. Up to a bias voltage of 4 V, there was no breakdown, and the reverse current of the heterojunctions somewhat increased with reverse bias voltage, while the photocurrent reached up to 580 and 690 µA for using 15 and 30 W/cm2 light power, respectively. Additionally, the ideal factors for CdS/Si heterojunction were 3.1 and 3.3 for 15 and 30 W/cm2 light power, respectively. These results exhibited high performance compared to the same heterojunction produced by other techniques. In addition, this opens the route for obtaining more enhancements of these values based on the changing use of sulfide structures in the heterojunction formation.

A polymeric nanocomposite film, composed of PMMA/PVDF and different amounts of CuO NPs, was successfully prepared using the casting method to enhance its electrical conductivity. Various techniques were employed to investigate their physicochemical properties. The addition of CuO NPs causes a noticeable difference in the intensities and locations of vibrational peaks in all bands, confirming the incorporation of CuO NPs inside the PVDF/PMMA. In addition, the broadening of the peak at 2θ = 20.6° becomes more intense with increasing amounts of CuO NPs, confirming the increase in the amorphous characteristic of PMMA/PVDF incorporated with CuO NPs in comparison with PMMA/PVDF. Furthermore, the image of the polymeric structure exhibits a smoother shape and interconnection of pore structure associated with spherical particles that agglomerate and give rise to a web-like organization that becomes a matrix. Increasing surface roughness is responsible for an increasing surface area. Moreover, the addition of CuO NPs in the PMMA/PVDF leads to a decrease in the energy band gap, and further increasing the additional amounts of CuO NPs causes the generation of localized states between the valence and conduction bands. Furthermore, the dielectric investigation shows an increase in the dielectric constant, dielectric loss, and electric conductivity, which may be an indication of an increase in the degree of disorder that confines the movement of charge carriers and demonstrates the creation of an interconnected percolating chain, enhancing its conductivity values compared with that without the incorporation of a matrix.

A graphene oxide (GO)/poly 3-methyl aniline (P3MA) photodetector has been developed for light detection in a broad optical region: UV, Vis, and IR. The 3-methyl aniline was initially synthesized via radical polymerization using an acid medium, i.e., K2S2O8 oxidant. Consequently, the GO/P3MA composite was obtained through the adsorption of GO into the surface of P3MA. The chemical structure and optical properties of the prepared materials have been illustrated via XRD, FTIR, SEM, and TEM analysis. The absorbance measurements demonstrate good optical properties in the UV, Vis, and near-IR regions, although a decrease in the bandgap from 2.4 to 1.6 eV after the composite formation was located. The current density (Jph) varies between 0.29 and 0.68 mA·cm−2 (at 2.0 V) under dark and light, respectively. The photodetector has been tested using on/off chopped light at a low potential, in which the produced Jph values decrease from 0.14 to 0.04 µA·cm−2, respectively. The GO/P3MA photodetector exhibits excellent R (and D) values of 4 and 2.7 mA·W−1 (0.90 × 109 and 0.60 × 109 Jones) in the UV (340 nm) and IR (730 nm) regions, respectively. The R and D values obtained here make the prepared photodetector a promising candidate for future light detection instruments.

Graphitic carbon nitride (G-C3N4) and NiS-NiO/G-C3N4 nanocomposite have been synthesized via combustion and hydrothermal techniques, respectively. The chemical and morphological properties of these materials were confirmed using different analytical methods. SEM confirms the formation of G-C3N4 sheets containing additional petal-like shapes of NiS-NiO nanoparticles. The electrochemical testing of NiS-NiO/G-C3N4 symmetric supercapacitors is carried out from 0.6 M HCl electrolyte. Such testing includes charge/discharge, cyclic voltammetry, impedance, and supercapacitor stability. The charge/discharge time reaches 790 s at 0.3 A/g, while the cyclic voltammetry curve forms under a high surface area. The produced specific capacitance (CS) and energy density values are 766 F/g and 23.55 W.h.kg−1, correspondingly.

Graphitic carbon nitride (G-C3N4) was synthesized through the direct combustion of urea in the air. The CoS-Co2O3/G-C3N4 composite was synthesized via the hydrothermal method of G-C3N4 using cobalt salts. The morphological and chemical structures were determined through XRD, XPS, SEM, and TEM. XRD and XPS analyses confirmed the chemical structure, function groups, and elements percentage of the prepared nanocomposite. SEM measurements illustrated the formation of G-C3N4 sheets, as well as the flower shape of the CoS-Co2O3/G-C3N4 composite, evidenced through the formation of nano appendages over G-C3N4 sheets. TEM confirmed the 2D nanosheets of G-C3N4 with an average width and length of 80 nm and 170 nm, respectively. Two symmetric electrodes for the supercapacitor from the CoS-Co2O3/G-C3N4 composite. Electrochemical measurements were carried out to determine the charge/discharge, cyclic voltammetry, stability, and impedance of the prepared supercapacitor. The measurements were carried out under acid (0.5 M HCL) and basic (6.0 M NaOH) mediums. The charge and discharge lifetime values in the acid and base medium were 85 and 456 s, respectively. The cyclic voltammetry behavior was rectangular in a base medium for the pseudocapacitance feature. The supercapacitor had 100% stability retention up to 600 cycles; then, the stability decreased to 98.5% after 1000 cycles. The supercapacitor displayed a specific capacitance (CS) of 361 and 92 F/g, and an energy density equal to 28.7 and 30.2 W h kg−1 in the basic and acidic mediums, respectively. Our findings demonstrate the capabilities of supercapacitors to become an alternative solution to batteries, owing to their easy and low-cost manufacturing technique.

The controlled-release characteristic of drug delivery systems is utilized to increase the residence time of therapeutic agents in the human body. This study aimed to formulate and characterize salsalate (SSL)-loaded chitosan nanoparticles (CSNPs) prepared using the ionic gelation method and to assess their in vitro release and antibacterial and antibiofilm activities. The optimized CSNPs and CSNP–SSL formulation were characterized for particle size (156.4 ± 12.7 nm and 132.8 ± 17.4 nm), polydispersity index (0.489 ± 0.011 and 0.236 ± 132 0.021), zeta potential (68 ± 16 mV and 37 ± 11 mV), and entrapment efficiency (68.9 ± 2.14%). Physicochemical features of these nanoparticles were characterized using UV–visible and Fourier transform infrared spectroscopy and X-ray diffraction pattern. Scanning electron microscopy studies indicated that CSNPs and CSNP–SSL were spherical in shape with a smooth surface and their particle size ranged between 200 and 500 nm. In vitro release profiles of the optimized formulations showed an initial burst followed by slow and sustained drug release after 18 h (64.2 ± 3.2%) and 48 h (84.6 ± 4.23%), respectively. Additionally, the CSNPs and CSNP–SSL nanoparticles showed a sustained antibacterial action against Staphylococcus aureus (15.7 ± 0.1 and 19.1 ± 1.2 mm) and Escherichia coli (17.5 ± 0.8 and 21.6 ± 1.7 243 mm). Interestingly, CSNP–SSL showed better capability (89.4 ± 1.2% and 95.8 ± 0.7%) than did CSNPs in inhibiting antibiofilm production by Enterobacter tabaci (E2) and Klebsiella quasipneumoniae (SC3). Therefore, CSNPs are a promising dosage form for sustained drug delivery and enhanced antibacterial and antibiofilm activity of SSL; these results could be translated into increased patient compliance.

Two-dimensional (2D) materials have attracted significant attention with their high optical response due to their interesting and unique fundamental phenomena. A lateral 2D MoS2 nanosheets was prepared via a facile one-step electrophoretic deposition method on polyethylene terephthalate (PET)/ITO. These nanosheets have been used as photoelectrode materials for photoelectrochemical (PEC) hydrogen generation and optoelectronics. The chemical structure and morphology were confirmed using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The optical absorbance of the 2D MoS2 nanosheets extended to the UV, Vis, and near-IR regions with a bandgap value of 1.59 eV. The testing of the prepared photoelectrode material, PET/ITO/MoS2, was carried out through a three-electrode system, in which the current density (Jph) value represents the rate of H2 gas evaluated. The Jph enhanced under light illumination compared to the dark conditions with values of 0.4 to 0.98 mA·cm−2, respectively. The produced photocurrent at V = 0 V was 0.44 mA·cm−2. This confirms the great abilities of the PET/ITO/MoS2 photoelectrode in light detection and hydrogen generation with high photoresponsivity values. Soon, our team will work on the development of a prototype of this three-electrode cell to convert the water directly into H2 fuel gas that could be applied in houses and factories, or even in advanced technology such as spacecraft and airplane F-35s by providing H2 gas as a renewable energy source.

Due to a suitable band gap and high light absorption behavior, Bi2S3 is showing major success in photo-to-current conversion applications. In this current work, the authors used a low-cost nebulizer spray pyrolysis method to create nano-sized pure and unique Eu contents (1–5 wt.%)-loaded Bi2S3 thin layers by taking bismuth nitrate and thiourea as the source materials. The parent and Eu doped Bi2S3 thin films, deposited on a well-cleaned glass substrate at 350 °C, were analyzed using a variety of characterization approaches, including FESEM, EDS, XRD, PL, UV-Vis, and I-V, to describe the morphologies, compositions, crystallinity, defect states, band gap, and photodetection capability, respectively. The X-ray diffraction outcomes confirmed an orthorhombic polycrystalline structure for all Eu concentrations, and they were highly oriented along the (130) plane. Incorporation of Eu into the host matrix improves the intensity of all the peaks, and the crystallite size (25 nm) was found to be highest for the 3% Eu doped Bi2S3 thin film. The formation of a nanowire-like morphology was confirmed thorough field emission electron microscopy analysis, which is preferred for photo detectors. Upon excitation at 325 nm, grown pure and Eu doped Bi2S3 thin films indicated five emission peaks at 387, 418, 439, 480, and 523 nm, respectively. All the films showed significant absorption in the UV region, and importantly, a narrowing of the band gap is seen from 2.29 to 2.17 eV. Finally, the current-voltage characteristics of the pure and Eu doped Bi2S3 thin films were tested using silver contacts as electrodes. The results showed that the 3% Eu doped Bi2S3 sample showed a higher UV photocurrent characteristic, with high specific detectivity (1.82 × 1010 Jones), photoresponsivity (3.88 × 10−1 AW−1), external quantum efficiency (125%), and rapid photo response, as well as a recovery speed of 0.3 s and 0.4 s, due to the effective light absorption and photocarrier generation. We believe that our study may provide a cost-effective approach for UV photosensor applications.

We have fabricated α-Sn/Ge quantum well heterostructures by sandwiching nano-films of α-Sn between Ge nanolayers. The samples were grown via e-beam deposition and characterized by Raman spectroscopy, atomic force microscopy, temperature dependence of electrical resistivity and THz time-resolved spectroscopy. We have established the presence of α-Sn phase in the polycrystalline layers together with a high electron mobility μ = 2500 ± 100 cm2 V−1 s−1. Here, the temperature behavior of the resistivity in a magnetic field is distinct from the semiconducting films and three-dimensional Dirac semimetals, which is consistent with the presence of linear two-dimensional electronic dispersion arising from the mutually inverted band structure at the α-Sn/Ge interface. As a result, the α-Sn/Ge interfaces of the quantum wells have topologically non-trivial electronic states. From THz time-resolved spectroscopy, we have discovered unusual photocurrent and THz radiation generation. The mechanisms for this process are significantly different from ambipolar diffusion currents that are responsible for THz generation in semiconducting thin films, e.g., Ge. Moreover, the THz generation in α-Sn/Ge quantum wells is almost an order of magnitude greater than that found in Ge. The substantial strength of the THz radiation emission and its polarization dependence may be explained by the photon drag current. The large amplitude of this current is a clear signature of the formation of conducting channels with high electron mobility, which are topologically protected.

MoO3 thin films are fabricated using nebulizer spray pyrolysis technique, which is doped with Fe at various concentrations of 1, 2, 3, and 4% for ammonia gas sensors application at room temperature. X-ray diffraction (XRD) study confirms the growth of the crystal by Fe doping up to 3%, nano rods shape morphology of the thin film samples observed by field emission scanning electron microscope (FESEM), reduction in bandgap is evidenced via UV-VIS spectrophotometer. Gas sensing study is performed using gas analyzing chamber attached with Keithley source meter. Since 3% Fe doped MoO3 sample displayed nano rods over the film surface which exhibits highest sensitivity of 38,500%, in a short period of raise and decay time 54 and 6 s. Our findings confirms that the 3% Fe doped MoO3 films suitability for ammonia gas sensing application.

Al2O3-poly(vinyl alcohol) nanocomposite (Al2O3-PVA nanocomposite) was generated in a single step using an eco-friendly method based on the pulsed laser ablation approach immersed in PVA solution to be applicable for the removal of Ni(II) from aqueous solution, followed by making a physicochemical characterization by SEM, XRD, FT-IR, and EDX. After that, the effect of adsorption parameters, such as pH, contact time, initial concentration of Ni(II), and medium temperature, were investigated for removal Ni(II) ions. The results showed that the adsorption was increased when pH was 5.3, and the process was initially relatively quick, with maximum adsorption detected within 90 min of contact time with the endothermic sorption process. Moreover, the pseudo-second-order rate kinetics (k2 = 9.9 × 10−4 g mg−1 min−1) exhibited greater agreement than that of the pseudo-first-order. For that, the Ni(II) was effectively collected by Al2O3-PVA nanocomposite prepared by an eco-friendly and simple method for the production of clean water to protect public health.

NiO thin films deposed on a glass substrate, “NiO/glass”, are successfully prepared using a spray pyrolysis technique (SPT) at 460 °C and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray, Atomic force microscopy (AFM), spectroscopic ellipsometry (SE), Photoluminescence (PL) and diverse electric and magnetic studies. The structural investigation shows that the synthesized films crystallized in a cubic structure with (111) preferential orientation. The NiO layers exhibit a uniform grain of regular sizes with aggregates randomly distributed across their surface. The optical properties of the NiO thin films evidenced a normal optical dispersion as well as good transparency of the NiO films. An unpredicted ferromagnetic aspect was raised due to the high oxygen presence in the synthetized material. A high thermal dependency of the conductivity, as well as a semiconductor behavior of the grown NiO material, is also demonstrated.

A three-dimensional numerical modelling of a time-dependent, turbulent thermal plasma jet was developed to synthetize silicon nanopowder. Computational fluid dynamics and particle models were employed via COMSOL Multiphysics®v. 5.4 (COMSOL AB, Stockholm, Sweden) to simulate fluid and particle motion in the plasma jet, as well as the heat dependency. Plasma flow and particle interactions were exemplified in terms of momentum, energy, and turbulence flow. The transport of nanoparticles through convection, diffusion, and thermophoresis were also considered. The trajectories and heat transfer of both plasma jet fields, and particles are represented. The swirling flow controls the plasma jet and highly affects the dispersion of the nanoparticles. We demonstrate a decrease in both particles’ velocity and temperature distribution at a higher carrier gas injection velocity. The increase in the particle size and number affects the momentum transfer, turbulence modulation, and energy of particles, and also reduces plasma jet parameters. On the other hand, the upstream flame significantly impacts the particle’s behavior under velocity and heat transfer variation. Our findings open the door for examining thermal plasma impact in nanoparticle synthesis, where it plays a major role in optimizing the growth parameters, ensuring high quality with a low-cost technique.

Plasma parameters of radiofrequency discharge generated at low pressures in an argon-oxygen mixture addressed for biomedical surface sterilization have been optimized. Numerical results illustrate the density distributions of different species and electron temperatures during the electrical discharge process. The current discharge acting in the abnormal range decreases at higher oxygen gas flow rates. The temperature of electrons drops with pressure while it rises by adding oxygen. Nevertheless, electron density displays an adverse trend, exhibited by the electron’s temperature. The average particle density of the reactive species is enhanced in Ar/O2 compared to He/O2, which ensures a better efficiency of Ar/O2 in sterilizing bacteria than He/O2. The impact of oxygen addition on the discharge mixture reveals raised oxygen atom density and a reduction in metastable oxygen atoms. A pronounced production of oxygen atoms is achieved at higher frequency domains. This makes our findings promising for biomedical surface sterilization and leads to optimal parameter discharges used for sterilization being at 30% of oxygen gas ratio and 0.3 Torr pressure.

Chromium (Cr)-doped zinc oxide (ZnO) nanorods with wurtzite hexagonal structure were prepared through a thermal decomposition technique. The concentration effect of the Cr doping on the structural, morphological, and optical properties of the ZnO nanorods was established by correlating various measurements: transmission electron microscopy (TEM), photoluminescence (PL), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and several UV-visible studies. The obtained nanorods were investigated as photocatalysts for the photodegradation process of methyl orange (MO), under UV-vis light illumination. Different weights and time intervals were studied. A 99.8% photodegradation of MO was obtained after 100 min in the presence of 1 wt.% Cr III acetate hydroxide and zinc acetate dehydrate “ZnO-Cr1”. The kinetic rate constant of the reaction was found to be equal to 4.451 × 10−2 min−1 via a pseudo-first order rate model. Scavenger radicals demonstrated the domination of OH• radicals by those of O2•− superoxide species during the photodegradation. The interstitial oxygen site Oi is proposed to play a key role in the generation of holes in the valence band under visible irradiation. The ZnO-Cr1 photocatalyst displayed good cycling stability and reusability.