In this work, the chemical bath deposition (CBD) technique was utilized in the synthesis of transition metals/GO nanocomposites (Co₃O₄/MnO₂/NiO/GO) for applications in supercapacitor electrodes. The nanocomposites after characterization showed that the electrically conductive nature and wide surface area of graphene oxide (GO) accounted for its incorporation into the nanocomposites. The synergy between the nanocomposites accounts for their improved performance and stable phase. The XRD results revealed cubic, orthorhombic, cubic, and mixed phases for the Co₃O₄/GO (CG), MnO₂/GO (MG), NiO/GO (NG), and Co₃O₄/MnO₂/NiO/GO (CMNG), respectively; their morphologies showed platelet nanoparticles with few agglomerates, with an average particle size of 69 ± 12 nm, 37 ± 09 nm, 58 ± 36 nm, and 36 ± 08 nm, respectively. For the produced materials, electrochemical results revealed maximum specific capacitance values of 2482 F/g from cyclic voltammograms and 1280.48 F/g from the galvanometric test. The results showed that the composites outperform single transition metal oxide (TMO) electrodes, with graphene oxide boosting the electrode performance.

In this paper, the photocatalytic effect of Nb(x)/TiO₂ nanocomposites on the degradation of phenol red (PR) was studied. Nb(x)/TiO₂ nanocomposites are fabricated by a simple sol-gel route with new experimental conditions. The structural and optical properties were determined using high transmission electron microscopy (HRTEM), X-ray diffraction, Raman spectroscopy, photoluminescence, and UV-vis absorbance spectroscopy. Compared to pure anatase TiO₂, the recently fabricated Nb(x)/TiO₂ nanocomposite has a shift in the optical band edge to the visible wavelength. Consequently, it has high performance in adsorption capacity and photocatalytic activities. A time of 160 min has been observed to be suitable for mostly degradable 20 mgL⁻¹ of phenol red on Nb(2.0)/TiO₂ composite. The kinetic results were in good agreement with the first-order kinetic model at different concentrations. In addition, the results showed that the addition of Nb led to a significant degradation process. The decomposition of phenol red pollutants showed a synergistic effect of the Nb(2.0)/TiO₂ nanocomposites on wastewater treatment.

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 OH^- radicals 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 ${\mathrm{SO}}_4^{2-}$ and carbons are byproducts of PR degradation.

Red emitting materials are critical to a wide range of optoelectronic devices, such as displays, lasers, and light-emitting diodes. Ongoing research efforts are focused on enhancing their emission efficiency and improving their thermal and mechanical stability to meet the demands of advanced device applications. Accordingly, a host glass network with the composition 50P₂O₅-20ZnO-20Bi₂O₃-10BaO (PZBB) was proposed and reinforced with 1 mol% of Ce³⁺, Nd³⁺, or Ce³⁺/Nd³⁺ ions to produce efficient red emission with high thermal and mechanical stability. Structural changes due to compositional variations were analyzed via X-ray diffraction (XRD), density measurements, and Fourier transform infrared (FTIR) spectroscopy. These analyses revealed a high network tightness with a very slight increase with the introduction of Ce³⁺, Nd³⁺, or Ce³⁺/Nd³⁺ ions. The produced host PZBB and developed PZBBCe³⁺, PZBBNd³⁺, or PZBBCe³⁺-Nd³⁺ glasses exhibited high thermal stability and elasticity, confirming their potential for use in optoelectronic device applications. Distinctive absorption bands of Ce³⁺ and Nd³⁺ ions were detected across the 200–2500 nm spectral range. Excitation of the PZBBCe³⁺, PZBBNd³⁺, or PZBBCe³⁺-Nd³⁺ glasses at 308 nm resulted in red emission at 619 & 639 nm, 616 & 677 nm, or 626 nm, respectively. Oscillator strength, Judd–Ofelt, and gain analyses confirm the suitability of PZBBCe³⁺, PZBBNd³⁺, and PZBBCe³⁺-Nd³⁺ for efficient red emission applications. Gain cross section analysis reveals that PZBBCe³⁺-Nd³⁺ glass supports broadband and dual-ion emission, with potential energy transfer enhancing Nd³⁺-dominated red emission output, while Ce³⁺ (PZBBCe³⁺) and Nd³⁺ (PZBBNd³⁺) singly doped glasses show broad and selective gain, respectively—highlighting their suitability for tunable and narrow-linewidth red emission applications. Overall, the PZBBCe³⁺, PZBBNd³⁺, or PZBBCe³⁺-Nd³⁺ glasses demonstrated high photoluminescence efficiency in the red region, along with excellent thermal stability and elasticity, making them promising candidates for single- and dual-wavelength optoelectronic applications.

In this work, the effect of KBrO3 on the photodegradation mechanism of Nb-TiO₂ nanocomposites was analyzed. The photocatalytic activities of Nb-TiO₂ were evaluated by using a high concentration of phenol red (PR). Nb-TiO₂ nanocomposites were fabricated by a simple sol–gel route with new experimental conditions. HRTEM and EDX were used to study the structural properties of the Nb-TiO₂ nanocomposites. KBrO₃ decreased the degradation time of 20 mg·L⁻¹ of phenol red to 110 min, shorter than that in our previous work without KBrO₃. In addition, the results showed that the addition of KBrO₃ led to a significant degradation process, which reached an efficiency of 95%. The fast decomposition of the PR pollutants was due to the charge transfer between the KBrO₃ and Nb-TiO₂ nanocomposites in the wastewater treatment.