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Green synthesis is a reliable way to synthesize metal oxide nanoparticles (NPs) without affecting the environment. Plant extracts act as reducing agents that favor the synthesis of NPs. In this study, jackfruit aqueous extract was used as a fuel in the solution combustion synthesis of lanthanum oxide (La2O3) NPs. X-ray diffraction (XRD) confirmed the formation of the hexagonal structure of La2O3 NPs. The scanning electron microscope (SEM) and energy dispersive X-ray (EDS) spectrum confirm the needle-shaped morphology and purity of the La2O3 NPs, respectively. Furthermore, La2O3 was utilized as a photocatalyst for the photodegradation of methylene blue dye under visible light radiation, demonstrating high efficiency within 90 min of light irradiation. The electrochemical characteristics of La2O3 were studied using a carbon paste electrode in a 0.1 M HCl solution. These La2O3 samples exhibited superior sensitivity in cyclic voltammetry tests towards the detection of ascorbic acid and lead nitrate. Consequently, La2O3 holds potential for applications in electrochemical sensor technology. [ABSTRACT FROM AUTHOR]

Lithium-doped anatase-TiO2 nanoparticles (LixTi1-xO2 NPs, x = 0, 0.05, 0.10, 0.15 and 0.20) could be synthesized by a simple sol–gel process. X-ray diffraction (XRD) results displayed the tetragonal (space group: I41/amd) of polycrystalline TiO2 anatase phase. The spectroscopy results of Raman and FT-IR confirmed the anatase phase of TiO2 through the specific modes of metal oxides vibration in the crystalline TiO2. Surfaces micrographs by scanning electron microscope (SEM) of agglomerated LixTi1-xO2 NPs showed a spongy like morphology. Transmission electron microscope (TEM) illustrated a cuboidal shape of dispersed NPs with particle size distributed in a narrow range 5–10 nm. Bruanauer Emmett-Teller (BET) results showed the increased surface area of LixTi1−xO2 NPs with increasing Li content. LixTi1-xO2 NPs (x = 0.05–0.20) working electrodes illustrated a pseudocapacitive behavior with excellent electrochemical properties through the whole cycles of GCD test. Interestingly, Li0.1Ti0.9O2 NPs electrode illustrated a high performance in terms of maximum specific capacitance 822 F g−1 at 1.5 A g−1 in 0.5 M Li2SO4 electrolyte, with excellent capacitive retention 92.6% after 5000 cycles GCD test. [ABSTRACT FROM AUTHOR]

The main goal of this work is to study the effects of some transition metal-oxides, i.e. ZnO, TiO2, and Fe2O3, on inhibition of spinel formation during cordierite fabrication from granite waste, talc, and alumina by direct coagulation casting method. Moreover, the effect of these oxides on sinterability, microstructure, hardness and electrical properties was achieved. The casted specimens were sintered at different temperatures then examined by X-ray diffraction technique to follow the formed phases. The physical properties were determined according to Archimedes rule. The microstructure was also investigated by scanning electron microscope, while the hardness was determined by Vicker's method. The electrical properties were evaluated by an impedance analyzer. The results indicated that sintered cordierite-spinel ceramics were successfully prepared with inhibition of spinel formation after addition of some transition metals and sintering up to 1250 °C. ZnO promoted the formation of spinel while TiO2 and Fe2O3 inhibited the formation of spinel and promoted the formation of cordierite. The ZnO-containing cordierites exhibited their best properties after sintering at 1200 °C, while the samples containing TiO2 and Fe2O3 showed their best properties after sintering at 1250 °C. The physical, mechanical and electrical properties were improved after increasing the amount of added metal oxides. The dielectric constant values were higher for the samples that contain TiO2 than those contain Fe2O3 and ZnO. Moreover, the hardness of all samples was in a narrow range of 6.14–6.61 GPa. [ABSTRACT FROM AUTHOR]

Bismuth based metal oxides are regarded as potential candidates for fabricating photoelectrodes due to their cost-effectiveness, high stability, and significant light absorbing capability. Hence, our present study focuses on rendering an extensive evaluation of nano-sized bismuth tungstate (Bi2WO6) as photoanodes for photoelectrochemical water splitting activity. Bismuth tungstate nanoparticles have been prepared by a facile solvothermal route, and their structural, morphological, elemental composition, and optical properties have been characterized by employing powder X-ray diffraction analysis (PXRD), high-resolution scanning electron microscope (HRSEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-DRS) technique. For Bi2WO6 sample, the onset potential obtained for OER under dark and light conditions are ηdark = 0.83 V and ηlight = 0.71 V vs. Ag/AgCl respectively. The magnitude of photocurrent density at 1.23 V vs. RHE has been measured as 0.17 µA/cm2. From the Mott–Schottky plot, the flat band potential (Efb) for Bi2WO6 photocatalyst has been obtained as − 0.38 V vs. Ag/AgCl. Nanosized Bi2WO6 exhibited low onset potential, good photocatalytic stability, and suitable band edge potentials facilitating them to act as an efficient photoanode under stimulated solar light irradiation. [ABSTRACT FROM AUTHOR]