ZnO and CuO nanoparticles (NPs) were synthesized using an argon plasma jet with treatment times of 5, 10, 15, and 20 min. XRD Investigation verified the existence of hexagonal wurtzite ZnO and monoclinic CuO phases. The average crystallite sizes were determined to be 27.98 nm for ZnO and 26.95 nm for CuO. UV-vis absorption spectra revealed an increase in absorbance with longer plasma treatment times, attributed to heightened crosslinking and defects. Extinction coefficient and optical conductivity also demonstrated an upward trend with treatment duration. The Urbach energy, indicative of structural disorders, exhibited an increase from 0.088 to 0.112 eV for CuO and 0.102 to 0.134 eV for ZnO as treatment time increased. Additionally, the bandgap energy decreased from 3.73 to 3.53 eV for CuO and 3.90 to 3.43 eV for ZnO with prolonged treatment. This reduction in bandgap and the increases in Urbach energy, extinction coefficient, and optical conductivity with extended plasma treatment are attributed to heightened structural defects and disorders caused by plasma-induced bond breaking and crosslinking. Overall, the argon plasma jet proved effective in synthesizing ZnO and CuO NPs with tunable optical and electronic properties through the controlled adjustment of treatment time.

In the current framework, the n-SnO2/n-CdS/p-Si heterostructure was fabricated at differ-ent tin dioxide (SnO2) thicknesses (d = 30, 60, 90, 120, 150, and 180 nm). In this device,nickel (Ni) and platinum (Pt) strips were used as back and front contact electrodes, respec-tively. The structural and optical properties of the SnO2 cap layers were studied. Usinga frequency of 10  MHz, a typical dark capacitance–voltage (C–V) characteristic of thefabticated heterostructure was measured to determine the electronic parameters. In orderto understand the behavior of the fabricated device under dark conditions, the current den-sity–voltage (J–V) characteristics were analyzed. The measurements showed a significantrectifying behavior, demonstrating the junction’s good rectification characteristic. Thedevices’ performance parameters, including open-circuit voltage (Voc), short-circuit currentdensity (JSC), fill factor (FF), and power conversion efficiency (PCE), were all discoveredto be affected by the cap layer’s thickness when subjected to AM1.5 illumination. In thisstudy, the higher thickness window layer had a power conversion efficiency of 14.25%.Remarkably, the addition of a cadmium sulfide buffer layer, and changing the thicknessof the SnO2 cap layer were critical in improving the photovoltaic properties, with the suit-ability of the last SnO2 cap layer confirmed due to its good structural, optical, quantumefficiency ?, spectral photoresponsivity ℜ and photovoltaic properties.
 

Zn1-xFexO films with x = 0, 5, 10, 15 and 20 at.% were prepared under high vacuum by the electron beam gun evaporation. The impact of Fe doping concentration on the films' structural, optical and magnetic characteristics has been taken into account. The patterns of XRD for all films at various Fe concentrations showed wurtzite-type structures. The results show that the size of nano-films reduces from 24 nm (0%) to 11 nm (0.20%) with elevating Fe content, which is owing to the difference between the ionic radii of Zn and Fe. Peaks associated with the elements to be seen were visible in the XPS spectra of undoped and 10% Fe-doped ZnO nanoparticles produced by the precipitation process: zinc (Zn), iron (Fe), and oxygen (O). The optical constants (n, k) of the Zn1-xFexO films were obtained by the SE measurements by an ellipsometric model, allowing for the verification of the Fe3+ ions in Fe-doped ZnO. With the addition of Fe, the energy band gap decreased from 3.44 eV to 3.28 eV. M-H measurements revealed room-temperature ferromagnetism in Fe-doped ZnO thin film. As the Fe concentration rises, the magnetization increases until it reaches a concentration of 15%, at which point it starts to decrease. This decrease in magnetization was attributable to the spinel phase, which was seen in the XRD spectra. These findings imply that Fe-doped ZnO is a highly suggested material for the creation of spintronic and optoelectronic devices.

In recent times, the global landscape of disease detection and monitoring has been profoundly influenced by the convergence of nanotechnology and biosensing techniques. Biosensors have enormous potential to monitor human health, with flexible or wearable variants, through monitoring of biomarkers in clinical and biological behaviors and applications related to health and disease, with increasing biorecognition, sensitivity, selectivity, and accuracy. The emergence of nanomaterial-based biosensors has ushered in a new era of rapid and sensitive diagnostic tools, offering unparalleled capabilities in the realm of disease identification. Even after the declaration of the end of the COVID-19 pandemic, the demand for efficient and accessible diagnostic methodologies has grown exponentially. In response, the integration of nanomaterial biosensors into breathalyzer devices has gained considerable attention as a promising avenue for low-cost, non-invasive, and early detection of COVID-19. This review delves into the forefront of scientific advancements, exploring the potential of emerging nanomaterial biosensors within breathalyzers to revolutionize the landscape of COVID-19 detection, providing a comprehensive overview of their principles, applications, and implications.

In this work, the deposition of titanium nitride (TiN) thin film using direct current (DC) sputtering technique and its application as diffusion barriers against copper interconnect was presented. The deposited film was analyzed by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS) techniques. XRD patterns showed the face-centered cubic (FCC) structure for the TiN/SiO2/Si film, having (111) and (200) peaks and TiN (111), Cu(111), and Cu(200) peaks for Cu/TiN/SiO2/Si film. FESEM images revealed that the grains were homogeneously dispersed on the surface of the TiN film, having a finite size. XPS study showed that Ti2p doublet with peaks centered at 455.1 eV and 461.0 eV for TiN film was observed. Furthermore, the stoichiometry of the deposited TiN film was found to be 0.98. The sheet resistance of the TiN film was analyzed by using a four-point probe method, and the resistivity was calculated to be 11 µΩ cm. For the utilization, TiN film were tested for diffusion barrier performance against Cu interconnect. The results exhibited that TiN film has excellent performance in diffusion barrier for copper metallization up to a temperature of 700 ◦C. However, at a higher annealing temperature of 800 ◦C, the formation of Cu3Si and TiSi2 compounds were evident. Thus, stoichiometric TiN film with high thermal stability and low resistivity produced in this study could be applied for the fabrication of microelectronic devices.

In this study, the enhanced photodegradation of a high-concentration phenol red (PR) using very fine TiO2 nanocrystals by adding a KBrO3 electron acceptor was reported for the first time. The structural study on TiO2 nanocrystals using HRTEM, XRD, Raman, and EDX was performed and it confirmed the anatase phase of TiO2 nanocrystals. UV–Vis absorbance of 20 mg.L−1 PR was measured and the photodegradation was extracted. The KBrO3 concentration effects exhibited an important enhancement in the degradation of PR dye. The efficiency of PR was increased during 110 min from 75% of pure TiO2 to 92% and 98% of TiO2 with 1 mg and 5 mg KBrO3 , respectively. For different samples, a first-order kinetic of dye degradation is confirmed. The instantaneous amount of degraded dye increased from 150 to 180 and 197 mg/g TiO2 with 1 mg and 5 mg KBrO3 , respectively. The mechanism of the photodegradation reaction confirms the effect of OHradicals on increasing the photocatalytic activities. The addition of electron acceptors KBrO3 improved the photocatalysis rate, where it prevented e-h recombination through conduction band electron capture, which increases the concentration of hydroxyl radicals. The proposed mechanism and results were supported by photocurrent measurements and a Raman spectra analysis of the final photodegraded products. The photocurrent of TiO2 was observed at 1.2 µA, which was significantly improved up to 13.2, and 21.3 µA with the addition of 1 mg and 5 mg of KBrO3 . The Raman spectra of the final products confirmed that SO2− 4 and carbons are byproducts of PR degradation.

The faradic asymmetric electrodes have recently attracted attention in capacitive deionization (CDI) because of their capability to remove both Na⁺ and Cl⁻ ions from saline solution to meet the freshwater requirements. However, the fabrication of CDI electrodes that are high-performing and stable remains a challenge. In this work, an asymmetric electrode with highly stable CDIs has been fabricated by using reduced graphene oxide (RGO) as positive electrodes and spherical-like manganese dioxide nanoparticles decorated RGO sheets (MnO₂/RGO) as negative electrodes to selectively capture salt ions from saline solution. MnO₂/RGO electrodes exhibit a large specific capacitance of about 485 F g⁻¹ at 10 mV s⁻¹ in NaCl with lower internal resistance, which is significantly higher than that of recent electrode materials. Due to the superior specific capacitance and lower internal resistance behavior of MnO₂/RGO electrodes, asymmetric CDI device has been assembled for the desalination of salt using saline water. Especially, MnO₂/RGO//RGO-based asymmetric CDI device shows higher salt uptake capacity (SAC) of 52 mg g⁻¹ with higher average salt adsorption capacity (ASAR) of 2.7 mg g⁻¹ min⁻¹ than recently reported electrode materials. Furthermore, the recycling studies indicate that MnO₂/RGO//RGO electrodes are promising electrode materials for prolonged CDI operation. In summary, the studies confirmed that the MnO₂/RGO system offers excellent potential for producing portable drinking water by capacitive deionization of seawater.