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Novel and economic supports were prepared to facilitate the NiO‐reducibility and enrich the hydrogen production from the catalytic conversion of methane. Mixed (CaTi)‐oxides of CaO %=10, 20, and 30 were synthesized by direct compositing of CaCO3 and one‐pot synthesized (TiO2)‐nanoparticles. The developed nanostructures were characterized by a high‐resolution transmission electron microscope, X‐ray diffraction (XRD), temperature programmed reduction (TPR), and N2 adsorption‐desorption measurements. Practically, (Ni@30 % CaTiO3) the catalyst of cubic morphology, achieved a high hydrogen production ratio of 62.2 %. The incorporation of CaO to TiO2 hindered the formation of NiTiO3@NiCaTiO3 phases and facilitated the fast reduction of NiO‐phase to Ni (as revealed by temperature programmed reduction (TPR) and XRD. The formation of well‐ordered carbon nanotubes (CNTs) as valuable by‐products was also possible by these nanocomposites. The developed catalysts exhibited remarkable catalytic and structural stabilities. These results reflect the effective use of abundant CaO inorganic salt to enrich the H2 production by (CaTiO3) supports for potential and green energy production. [ABSTRACT FROM AUTHOR]

In this study, metal oxides nanoparticles heterogeneous photocatalysts prepared by coprecipitation and ultrasonic techniques were used for diesel desulfurization. They were characterized by scanning electron microscope, powder X-ray diffraction, energy dispersive analysis, diffused reflectance spectra, photoluminescence analysis and BET surface area. The surface area of catalyst B is larger than catalyst A confirming its higher reactivity. X-ray reflectance spectroscopy was used to analyze the sulfur contents in feed. Thiophene was used as a model fuel to evaluate the photocatalytic activity of catalysts A and B. Using the Scherrer equation, sharp and intense signals suggesting their higher degrees of crystallinity, with average crystal sizes for ZnO, Bi2O3, catalysts A and B, respectively; of 18, 14.3, 29.7, and 23.8 nm. The operational parameters of the desulfurization process were optimized and have been studied and the maximum sulfur removal was achieved via a further solvent extraction step. A diesel fuel with a 24 and 19 ppm sulfur content and hence a total sulfur removal of 94.6% and 95.7% was acquired for catalysts A and B, respectively (sulfur compounds concentration in diesel fuel feedstock was 450 ppm). These findings demonstrated that photocatalysts A and B are good and effective catalysts for desulfurization of diesel fuel. [ABSTRACT FROM AUTHOR]

Hydrogen production through the processes of ethanol catalytic steam reforming (SR) is one of the promising routes due to its extensive yield that can be gained. However, catalyst deactivation (as a result of coke formation) is a major drawback in such a process. Therefore, this research work introduces efficient MgO supported Cubic cobalt oxide catalyst for the process of ethanol SR. This catalyst was successfully able to produce gases that have high contents of CO-free hydrogen was produced (above 78%) at 500°C and various flow rates of feed. This catalyst had also avoided coke formation at that temperature while attaining capture of the in-situ produced CO2 gas. The employment of an operating temperature beyond 500°C, during the SR process, could reduce the percentages of hydrogen (in products) to less than 55%. Such increases in the operational temperature could leave behind the detection of coke deposits onto the catalyst surface. The presence of these deposits was confirmed visually as well as via Raman spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, the structural, thermal, photoluminescence, and optical properties of PVA/Gd2O3 nanocomposite film with different doses of gamma irradiation (0, 15, 30, 45, and 100 kGy) were studied. The Gd2O3 nanoparticles (NPs) were prepared via the co-precipitation technique, and PVA/Gd2O3 nanocomposite film was obtained via the solution casting method. The XRD data demonstrated the successful fabrication of Gd2O3 NPs and PVA/Gd2O3 nanocomposite film. Also, EDX spectra verified the elemental composition of PVA/Gd2O3 nanocomposite film. SEM images illustrated the surface morphology of the studied films. Additionally, a remarkable influence of gamma irradiation on thermal stability has been detected. Four prominent photoluminescence peaks were observed for the PVA/Gd2O3 nanocomposite films. Also, the energy gap decreases as the dose of gamma rays increases from 15 to 45 kGy and suddenly increases in the case of 100 kGy. Also, the Urbach's energy increases from 3.65 eV for un-irradiated PVA/Gd2O3 nanocomposite film to 6.9 eV at a dose of 45 kGy. Overall, the thermal stability, optical, and photoluminescence properties of irradiated PVA/Gd2O3 nanocomposite films make of them suitable materials for flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]

The ionic liquid (IL) 1‐octyl‐3‐methylimidazolium bromide/FeCl3 [OMIM]Br/FeCl3 was prepared with three molar ratios of [OMIM]Br/FeCl3 (0.5 : 1, 1 : 1, and 2 : 1), and fully characterized through 1H and 13C NMR, Fourier‐transform IR, and Raman spectroscopic techniques. The optical properties of the prepared [OMIM]Br/FeCl3 ILs were revealed via diffuse reflectance and photoluminescence spectra. The photocatalytic activity of [OMIM]Br/FeCl3 ILs as homogenous photocatalysts were investigated towards hydrogen generation from methanol/water mixtures under visible light irradiation. The FeCl3‐based IL with [OMIM]Br/FeCl3 molar ratio of 1 : 1 exhibited the highest visible light photocatalytic activity with a hydrogen productivity of 243.2 mmol h−1 g−1 and a hydrogen purity of 95.5 %; such a high hydrogen yield and purity was reported for the first time. It was proposed that [OMIM] Br acted as an electron acceptor, which delayed the electron‐hole pair recombination of FeCl3. Also, [OMIM] Br could capture the produced carbon dioxide that is released with hydrogen gas. Additionally, [OMIM] Br/FeCl3 could be reused six times with nearly the same photocatalytic activity. These outstanding credits in terms of hydrogen generation rate and purity plus the economic feasibility, through several cycles of reuse, could certify such an IL as a promising photocatalyst for employment in water splitting. This paper suggests ways forward for research to develop the use of ILs as efficient and effective photocatalysts for hydrogen generation via water splitting. [ABSTRACT FROM AUTHOR]