Yazar "Haladu, Shamsuddeen A." seçeneğine göre listele
Listeleniyor 1 - 6 / 6
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Enhanced photocatalytic degradation of methylene blue by nanocomposites prepared by laser ablation of Bi on CNT-a-Fe2O3 nanoparticles(Elsevier Sci Ltd, 2022) Manda, Abdullah A.; Elsayed, Khaled; Gaya, Umar İbrahim; Haladu, Shamsuddeen A.; Ercan, İsmail; Ercan, Filiz; Alheshibri, MuidhThe low conductivity and high combination rate of photogenerated electrons (e-) and photogenerated holes (h+) are the real challenges of photocatalysis. These problems could be mitigated by the synthesis of heterostructured nanocomposites (NCs). In this study, Bi@CNT-Fe2O3 nanocomposite was fabricated via pulsed laser ablation in liquid and characterized by UV-Vis spectroscopy, photoluminescence (PL), X-ray diffraction (PXRD) and field scanning electron microscopy (FESEM). These techniques revealed successfully the formation of CNT-alpha-Fe2O3 and Bi@CNT-alpha-Fe2O3 nanocomposites. The photocatalytic activities of the Fe2O3, CNT-alpha-Fe2O3, and Bi@CNT-Fe2O3 photocatalysts were evaluated by the degradation of methylene blue (MB) dye under ultraviolet (UV) light irradiation in the presence of a very low concentration of hydrogen peroxide (H2O2) as an oxidizing agent. The results show that the Bi@CNT-alpha-Fe2O3 NC has the highest photocatalytic degradation efficiency of MB which completes in 20 min of UV light irradiation. In addition, the obtained rate constants (min-1) of Bi@CNT-alpha-Fe2O3 NC were 1.3 and 3.4 times higher than those of CNT-alpha-Fe(2)O(3 )and alpha-Fe2O3. nanocatalysts, respectively.Öğe Fast one-pot laser-based fabrication of ZnO/TiO2-reduced graphene oxide nanocomposite for photocatalytic applications(Elsevier Ltd, 2023) Manda, Abdullah A.; Haladu, Shamsuddeen A.; Elsayed, Khaled; Gaya, Umar İbrahim; Alheshibri, M.; Al, Baroot, A.; Çevik, EmreLaser synthesis is rapidly emerging to be an efficient and unique method for the synthesis of a wide spectrum of nanomaterials owing to its ease of setup, simplicity, and generation of high-purity nanomaterials. This study explores a pulse laser ablation protocol in the synthesis of ZnO-TiO2 (ZT) and ZnO-TiO2-reduced graphene oxide (ZT-rGO) nanocomposites. The effect of rGO loading (5 %, 10 %, and 20 %) was investigated on the nature of the crystalline nanostructures formed, the increased thermal stability achieved, and the effective removal of methylene blue dye. Following fabrication, the nanocatalyst materials were characterized by TEM, PXRD, SEM/EDX, AFM, UV–Vis, TGA, and FTIR. Using UV illumination, the as-synthesized photocatalysts were evaluated in the photodegradation of methylene blue (MB) as a model dye pollutant. Among the nanocomposites, the ZT-rGO 5 % shows the best photocatalytic activity by having a preferential rate constant of 0.149 min?1. The nanocomposites were prepared in 30 min, providing 98.5 % MB removal within just 30 min, using 10 mg/L of MB and 20 mg/L of the catalyst. During the photodegradation process, the rGO component serves as an electron trap, thus enhancing the formation of holes which are the mainstay of any photocatalytic process. As demonstrated by the work reported, the laser ablation technique shows great promise in the fabrication of ZT-rGO nanocomposites and similar analogs relevant to the efficient decolorization of wastewater. © 2022 Elsevier LtdÖğe Investigation on structural, optical, thermal, and dielectric properties of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum nanocomposite prepared by pulsed laser ablation(Elsevier, 2024) Haladu, Shamsuddeen A.; Elsayed, Khaled A.; Ercan, Ismail; Ercan, Filiz; Kayed, T. S.; Demirci, Tuna; Yildiz, MesutPolymer nanocomposite films of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum (CP/ SMAC/Mo) were fabricated by pulsed laser ablation of Mo in the polymer solution for 10, 20, and 30 min. The films were then characterized by various analytical methods. X-ray diffraction (XRD) revealed that the addition of Mo to CP/SMAC removed the crystalline peaks of Mo without changing the amorphous nature of the copolymer. According to the scanning electron microscopy (SEM) and atomic force microscopy (AFM) patterns, Mo atoms were trapped in the amorphous polymer stacks. The energy -dispersive X-ray (EDX) spectrum features C, O, and Mo. FTIR confirmed the embedding of Mo in the polymers. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were carried out on the samples. The pristine polymer film exhibited a band gap energy of 2.9 eV, which decreased to 2.05 eV because of the loading of the Mo nanoparticles. The intensity of the photoluminescence (PL) peak of the films increases with ablation time such that the absorption intensity of the film at a lambda max of 426 nm increases by trifold during the 30 min of irradiation, which is consequently due to the increased amount of Mo in the nanostructure. The incorporation of Mo in the polymer matrix enhances the dielectric constant ( epsilon') (6.28 -18.13) and ac conductivity ( sigma ac ) (3.19 x 10 - 5 -1.12 x 10 -4 S/cm) of the polymer with negligible dielectric loss. The results suggest possible technological utilization of these materials in such applications as supercapacitors, light -emitting diodes, and organic optoelectronic devices, among others.Öğe Pulsed laser ablation-mediated facile fabrication of MoO3/TiO2/rGO nanocomposite as a photocatalyst for dye degradation(Elsevier Sci Ltd, 2024) Al-Otaibi, Amal L.; Elsayed, Khaled A.; Manda, Abdullah A.; Haladu, Shamsuddeen A.; Gaya, Umar Ibrahim; Ercan, Filiz; Kayed, T. S.In this work, for the first time, the MoO3/TiO2/rGO nanocomposites with different weight ratios of rGO (0%, 5%, 10%, and 20%) were fabricated using pulsed laser ablation technique. The as-fabricated nanocomposites were employed for photodegradation of Methylene Blue (MB) under UV light irradiation. The morphological, struc-tural, and chemical properties of the fabricated photocatalysts were characterized using XRD, TEM, SEM, UV -DRS, XPS, FTIR, TGA, DSC, and PL. Comparative experimental studies displayed that MoO3/TiO2/rGO nano -composites fabricated with 5% rGO showed the highest photocatalytic degradation (95%) of MB under UV irradiation. This superior photocatalytic performance could be ascribed to the narrow bandgap of the fabricated nanocomposites as well as the synergistic effect of the three components.Öğe Synthesis and Characterization of Cyclic Cationic Polymer and its Anti-corrosion Property for Low Carbon Steel in 15% HCl Solution(Esg, 2017) Haladu, Shamsuddeen A.; Umoren, Saviour A.; Ali, Shaikh A.; Solomon, Moses M.A new cyclic cationic polymer (CCP) bearing bis-3-phosphorylpropyl pendants was synthesized using chain-growth polymerization technique with ammonium persulphate (APS) as initiator. The synthesized polymer was characterized using FTIR, H-1 NMR and C-13 NMR techniques. The corrosion inhibition performance evaluation of the newly synthesized polymer for low carbon steel in 15% HCl was carried out using weight loss measurements at 25 - 60 degrees C, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and linear polarization resistance (LPR) techniques. The effect of addition of small amounts (5 mM) of ZnCl2 and KI on the corrosion inhibition performance of CCP was also assessed. Results obtained indicate that CCP acts as an inhibitor for low carbon steel corrosion in the aggressive acid environment. Inhibition efficiency increased slightly with increasing CCP concentration. Also, inhibition efficiency was found to decrease with increase in temperature. Addition of ZnCl2 and KI to CCP has profound effect on the corrosion inhibition performance, which was more pronounced with KI compared to ZnCl2. Corrosion protection efficiency followed the trend CCP + KI > CCP + ZnCl2 > CCP. The enhanced corrosion inhibition of CCP on addition of ZnCl2 and KI is due to synergistic effect as confirmed from the calculated synergistic parameter which was found to be greater than unity. Inhibition of low carbon steel corrosion in 15% HCl occurs by virtue of physical adsorption of CCP onto the steel surface which can be approximated by Langmuir adsorption isotherm model. The SEM/EDS images confirm the adsorption of CCP to form protective film on the low carbon steel surface.Öğe Synthesis of Ag nanoparticles-decorated on CNTs/TiO2 nanocomposite as efficient photocatalysts via nanosecond pulsed laser ablation(Elsevier Sci Ltd, 2022) Alheshibri, Muidh; Elsayed, Khaled; Haladu, Shamsuddeen A.; Magami, Saminu Musa; Al Baroot, Abbad; Ercan, İsmail; Ercan, FilizA simple, reproducible, and non-surfactant self-templating approach was developed for the synthesis of silver nanoparticles decorated on CNTs/TiO2 nanocomposite via a nanosecond pulsed laser ablation method. In addition, the effective use of the resulting nanocatalysts was carried out in the enhanced photocatalytic degradation of methylene blue dye contaminant. Following the synthesis of the nanocomposite catalysts, their morphology, heterostructure, and the nature of incorporation of their constituents were confirmed by TEM and SEM microscopy. In addition, characteristic diffraction patterns of the materials were studied by XRD powder diffraction method, confirming the crystalline nature of the nanocatalysts. The photoluminescence (PL) analysis provided information about the surface defects present as well as the electron-hole recombination properties of the prepared nanocatalysts. Despite the poor ultraviolet light absorption of the neat CNT and the TiO2 constituents beyond 400 nm, an efficient ultraviolet light-induced photodegradation of the methylene blue dye was successfully achieved. In this, by carrying out 50 min of ultraviolet light irradiation of the dye in the presence of the TiO2/CNT and the Ag/TiO2/CNT nanocomposite catalysts, 89.8% and 96 % reduction efficiencies were achieved, respectively. The experimental error associated with the photodegradation efficiency was within +/- 3%. The ultraviolet light-induced catalytic degradation of the dye follows first-order reaction kinetics, with rate constants of 3.95 x10-2 min-1 and 4.56 x 10-2 min-1 associated with the TiO2/CNT and the Ag/TiO2/CN catalyzed reactions, respectively.
