Structuring of ZnTiO3/TiO2 Adsorbents for the Removal of Methylene Blue, Using Zeolite Precursor Clays as Natural Additives

Adsorption is an effective method of removing harmful pollutants from air and water. In the present study, zeolites prepared by sol-gel method from two Ecuadorian clays were combined with precursor clays and the ZnTiO3/TiO2 semiconductor for adsorbing methylene blue (MB) as a water contaminant. The synthesized compounds were characterized using powder X-ray diffraction, X-ray fluorescence, scanning electron microscopy, energy dispersive X-ray, and surface area measurement. These compounds were combined to form cylindrical extrudates of 0.2 cm (diameter) and 1.0 cm (length). The adsorption characteristics of the composites were measured using batch sorption studies as a function of pH, initial concentration, and contact time. The pseudo-second-order model and the Langmuir isotherm model were better suited to the adsorption process. The equilibrium state was achieved around 180 min of adsorption, and a pH of 7 was established as the optimal operating condition. The maximum adsorption values of the dye were obtained with the composites derived from G-Clay, whose average adsorption capacity was 46.36 mg g−1, in contrast with composites derived from R-Clay, whose average adsorption value was 36.24 mg g−1. The results reflect that synthesized composites could be used potentially for the removal of cationic dye from wastewater.

Specifications study of Hydrophobic Silica Aerogel Doped with Rhodamine 6G Prepared via Sub-Critical Drying Technique

The influence of dye laser Rhodamine 6G (R6G) on the molecular structure of silica aerogel prepared by normal drying method is reported. The study also tests the effect of dye concentration on morphological and physical properties. Fourier Transform Infrared Spectroscopy (FTIR) was used to examine this effect, in addition to Field Emission Scanning Electron Microscopy (FESEM), contact angle, and surface area measurement. It was found from FTIR data that the dye laser stays with the inner structure of samples and, at high concentration, it gives a good influence by reducing (OH) band and increasing (CH) band, leading to changing the contact angle from (123ᴼ) to (145ᴼ). Whereas particle size varied from 22 nm to 47 nm after doping, resulting in a decrease in surface area from 673 m2/gm before doping to 357 m2/gm after doping. It was also found that the samples became lightweighted through the noticeable decrease in the amount of density from 0.28 to 0.17 gm/cm3.

Electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite cathode for ammonia synthesis from water and nitrogen

Purpose This paper aims to investigate the electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite (CFMo-CGDC) for the direct synthesis of ammonia from H2O and N2 under atmospheric pressure. Designs CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using X-ray diffraction (XRD), Brunauer–Emmet–Teller (BET) specific surface area measurement and scanning electron microscope (SEM). Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied. Findings CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using XRD, Brunauer–Emmet–Teller (BET) specific surface area measurement and SEM. Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied. Originality/value The usage of CFMo-CGDC composite as an electrocatalyst for the synthesis of ammonia directly from H2O and N2.

Catalytic hydrogenation of n-butene with nanosized Pt/NBCNT hybrid membranes reinforced with bacterial cellulose

One of the main challenges in the field of heterogeneous catalysis is the involvement of thin solid films and membranes and their application in flow systems. In this regard, we report here the application of self-supported bacterial cellulose (BC) reinforced nanosized platinum (Pt)/N-doped bamboo-like carbon nanotube (NBCNT) hybrid catalyst membrane with a thickness of 35 ± 5 µm in the hydrogenation of n-butene. To synthetized the BC-NBCNT/Pt nanohybrid membrane catalyst a simple impregnation route was applied in a two-step process. As-prepared material was tested in a continuous flow system and the conversion was followed directly by using Fourier transform infrared spectroscopy. Furthermore, the fabricated films were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and specific surface area measurement (Brunauer–Emmett–Teller). Hydrogenation performance was studied on both single and double films. Results revealed that 97% conversion of n-butene can be achieved using these bacterial cellulose reinforced hybrid membranes. Graphic abstract

Kinetic Study of the Adsorption of Polyphenols from Olive Mill Wastewater onto Natural Clay: Ghassoul

The aim of this study is based on natural clay as an adsorbent in the elimination of polyphenols from olive mill wastewater (OMW). This clay was analyzed using XRD, SEM/EDX, FTIR, surface area measurement (BET method), thermal analysis (TGA/DTA), and X-ray fluorescence (XRF) and then used in adsorption experiments. The results reveal that the best quantity of adsorption of polyphenols is 161 mg/g at the temperature of 25°C, but they decrease at 35°C and 45°C. A great agreement with pseudo-second-order and Freundlich model is represented by kinetic and isotherms models, and several parameters such as ΔG0, ΔS0, and ΔH0 were determined using the thermodynamic function relationship.

Silane Modification of Crumb Rubber on the Rheological Properties of Rubberized Asphalt

Because there is a lack of studies on rubberized asphalt based on silane coupling agent modification, KH-550 modified crumb rubber and rubberized asphalts incorporating normal rubber and modified rubber were prepared, respectively. The rheological properties of asphalt samples were evaluated by a dynamic shearing rheometer and a bending beam rheometer; then, mechanisms of KH-550 on rubber surface and functional group changes were analyzed by a Brunauer–Emmett–Teller specific surface area measurement and a Fourier transform infrared spectroscopy. The results imply that: (i) rubber surface area rises and chemical reactions accrue between rubber and asphalt; (ii) modified rubber achieves a more stable state within asphalt, which helps to enhance the mechanical properties of asphalt; (iii) modified rubber helps asphalt to dissipate stress so as to resist the formation of cracks and deformation under low temperature conditions.