Synthesis and Characterizations of Titanium Tungstosilicate and Tungstophosphate Mesoporous Materials

The work reports a development approach for the synthesis of novel multi-components mesoporous materials of titanium tungstate (meso-TiW) titanium tungstosilicate (meso-TiWSi) and tungstophosphate (meso-TiWP) mixed oxides that have high surface area and ordered mesoporous structures at nanometer length scale. Using the solvent evaporation-induced self-assembly (EISA) new oxides of bi- and tri-component of meso-TiW, meso-TiWSi and meso-TiWP oxides with different compositions and porosity were achieved. The physicochemical properties of the mesoporous oxides were characterized by X-ray diffraction, BET surface area analyzer, scanning, and transmission electron microscopes. Subject to the oxide composition, the obtained meso-TiW, meso-TiWSi and meso-TiWP exhibits high surface area, ordered 2D hexagonal mesostructured with order channels extended over a large area. The produced meso-TiW, meso-TiWSi, and meso-TiWP adsorbents exhibit good adsorption efficiency for the removal of Pb(II), Cd(II) and Hg(II) ions from water solution due to the presence of high surface area and accessibility of surface active sites. The adsorption efficiency of these mesoporous oxide reaches up to 95% and is found to be dependent contact time and adsorbents dose. The synthesis strategy is particularly advantageous for the production of new complex (multi-component) inorganic mesoporous materials that might have an application in the field of environmental, catalysis or energy storage and production

Determination of Cadmium and Lead in Sewage Sludge from the Middle Region (Misrata, Msallata and Tarhünah Cities) of Libya

The concentrations of cadmium and lead in sewage sludge samples were determined by Atomic Absorption Spectrometric Method. Samples of sewage sludge were obtained from three sewage treatment plants localised in Middle Region of Libya (Misrata, Msallata and Tarhünah cities). The results shows that, the mean levels of Cadmium for all regions are ranges from 81 to 123.4 ppm and these values are higher than the limitations for the international standard which are not registered more than 50 ppm (dry weight) in USA, Egypt and the EU countries. While, the lead concentrations are ranged from 8.0 to 189.2 ppm and all values are within the standard limits which graduated between (275–613) ppm

Exploiting the synergistic catalytic effects of CoPi nanostructures on Zr-doped highly ordered TiO2 nanotubes for efficient solar water oxidation

Photoelectrochemical (PEC) catalysis offers promising strategies for sustainable development. This study demonstrated the synergistic catalytic behavior of ZrO2 and a cobalt phosphate on anodized TiO2 nanotubes (TNTs), which significantly enhanced the PEC performance for visible-light-driven water splitting reactions. The sequential addition of ZrO2/CoPi-decorated TNTs was performed via electrodeposition and photoassisted electrodeposition. The substitution of Zr4+ by Ti4 can lead to the creation of oxygen vacancies, enabling electron trapping, reducing charge recombination, and thereby enhancing the charge transfer efficiency. Further, in the case of TNTs/ZrO2/CoPi photoanode, the CoPi WOC functioned as a hole-transfer relay to promote the water-splitting reaction. Specifically, incorporating ZrO2/CoPi rushes the surface reaction kinetics of TNTs and considerably improves charge transfer efficiency (ηCT = 90%), photocurrent density (0.86 mA/cm2 at 1.23 VRHE) and durability were obtained. Further, the mechanistic examination by impedance measurements showed the enhanced charge transfer, and surface conductivity for prepared materials. The proposed method can be widely used to develop electrodes made of other materials to produce solar fuels

Enhancing the Optical Absorption and Interfacial Properties of BiVO4 with Ag3PO4 Nanoparticles for Efficient Water Splitting

Photoelectrochemical water splitting using semiconductor materials has emerged as a promising approach to produce hydrogen (H2) from renewable resources such as sunlight and water. In the present study, Ag3PO4 nanoparticles were electrodeposited on BiVO4 photoanodes for water splitting. A remarkable water oxidation photocurrent of 2.3 mA·cm–2 at 1.23 V versus reversible hydrogen electrode with ∼100% Faradaic efficiency was obtained, which constitutes a notable increase compared to the pristine BiVO4 photoanode. It is demonstrated that the enhancement of optical absorption (above-band gap absorbance) and the decrease of surface losses after the optimized deposition of Ag/Ag3PO4 nanoparticles are responsible for this notable performance. Remarkably, this heterostructure shows promising stability, demonstrating 25% decrease of photocurrent after 24 h continuous operation. This approach may open new avenues for technologically exploitable water oxidation photoanodes based on metal oxides

Photoelectrochemical performance of strontium titanium oxynitride photo-activated with cobalt phosphate nanoparticles for oxidation of alkaline water

Photoelectrochemical (PEC) solar water splitting is favourable for transforming solar energy into sustainable hydrogen fuel using semiconductor electrodes. Perovskite-type oxynitrides are attractive photocatalysts for this application due to their visible light absorption features and stability. Herein, strontium titanium oxynitride (STON) containing anion vacancies of SrTi(O,N)3−δ was prepared via solid phase synthesis and assembled as a photoelectrode by electrophoretic deposition, and their morphological and optical properties and PEC performance for alkaline water oxidation are investigated. Further, cobalt-phosphate (CoPi)-based co-catalyst was photo-deposited over the surface of the STON electrode to boost the PEC efficiency. A photocurrent density of ~138 μA/cm at 1.25 V versus RHE was achieved for CoPi/STON electrodes in presence of a sulfite hole scavenger which is approximately a four-fold enhancement compared to the pristine electrode. The observed PEC enrichment is mainly due to the improved kinetics of oxygen evolution because of the CoPi co-catalyst and the reduced surface recombination of the photogenerated carriers. Moreover, the CoPi modification over perovskite-type oxynitrides provides a new dimension for developing efficient and highly stable photoanodes in solar-assisted water-splitting reactions

Structure and electrochemical activity of nickel aluminium fluoride nanosheets during urea electro-oxidation in an alkaline solution

An electrocatalyst of potassium nickel aluminium hexafluoride (KNiAlF6) nanosheets has been prepared using solid-phase synthesis at 900 °C. X-ray diffraction, scanning electron microscopy, and conductivity studies confirmed the formation of KNiAlF6 nanosheets having a cubic defect pyrochlore structure with an average thickness of 60–70 nm and conductivity of 1.297 × 103 S m−1. The electrochemical catalytic activity of the KNiAlF6 nanosheets was investigated for urea oxidation in alkaline solution. The results show that the KNiAlF6 nanosheets exhibit a mass activity of ∼395 mA cm−2 mg−1 at 1.65 V vs. HRE, a reaction activation energy of 4.02 kJ mol−1, Tafel slope of 22 mV dec−1 and an oxidation onset potential of ∼1.35 V vs. HRE which is a significant enhancement for urea oxidation when compared with both bulk Ni(OH)2 and nickel hydroxide-based catalysts published in the literature. Chronoamperometry and impedance analysis of the KNiAlF6 nanosheets reveal lower charge transfer resistance and long-term stability during the prolonged urea electro-oxidation process, particularly at 60 °C. After an extended urea electrolysis process, the structure and morphology of the KNiAlF6 nanosheets were significantly changed due to partial transformation to Ni(OH)2 but the electrochemical activity was sustained. The enhanced electrochemical surface area and the replacement of nickel in the lattice by aluminium make KNiAlF6 nanosheets highly active electrocatalysts for urea oxidation in alkaline solution

The multifaceted presentation of chronic recurrent multifocal osteomyelitis: A series of 486 cases from the Eurofever international registry

Objectives. Chronic non-bacterial osteomyelitis (CNO) or chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory disorder characterized by sterile bone osteolytic lesions. The aim of this study was to evaluate the demographic data and clinical, instrumental and therapeutic features at baseline in a large series of CNO/CRMO patients enrolled in the Eurofever registry. Methods. A web-based registry collected retrospective data on patients affected by CRMO/CNO. Both paediatric and adult centres were involved. Results. Complete baseline information on 486 patients was available (176 male, 310 female). The mean age of onset was 9.9 years. Adult onset (>18 years of age) was observed in 31 (6.3%) patients. The mean time from disease onset to final diagnosis was 1 year (range 0-15). MRI was performed at baseline in 426 patients (88%), revealing a mean number of 4.1 lesions. More frequent manifestations not directly related to bone involvement were myalgia (12%), mucocutaneous manifestations (5% acne, 5% palmoplantar pustulosis, 4% psoriasis, 3% papulopustular lesions, 2% urticarial rash) and gastrointestinal symptoms (8%). A total of 361 patients have been treated with NSAIDs, 112 with glucocorticoids, 61 with bisphosphonates, 58 with MTX, 47 with SSZ, 26 with anti-TNF and 4 with anakinra, with a variable response. Conclusion. This is the largest reported case series of CNO patients, showing that the range of associated clinical manifestations is rather heterogeneous. The study confirms that the disease usually presents with an early teenage onset, but it may also occur in adults, even in the absence of mucocutaneous manifestations

International cohort study for pediatric Behçet’s Disease: update 2011

PubMe