Sharif Digital Repository

A triple photocatalytic composite of biochar, metal–organic framework, and phosphomolybdic acid was prepared through hydrothermal treatment of iron (III) chloride hexahydrate, terephthalic acid, lavandulifolia-derived biochar, and phosphomolybdic acid. It was characterized and utilized for photodegradation of Rhodamine-B (RhB) dye under visible-light irradiation. Investigations of reaction variables confirmed that, the highest yield of 96.2% was achieved at ambient temperature using 0.07 g of catalyst at pH of 7, and a dye concentration of 10 ppm. Under these optimum conditions, Methyl Orange (MO) dye was also degraded to yield 93% removal. In addition, the kinetic and thermodynamic... 

This study investigated the feasibility of using calcined Salmon fish bone wastes as an inexpensive and reusable catalyst-support for the biodiesel production via transesterification of sunflower oil. In this venue, a series of catalysts were synthesized by impregnating potassium hydroxide (KOH) onto the calcined Salmon fish bones. The as-prepared catalysts were characterized through several techniques, including the FESEM, BET-BJH, TGA, FT-IR, and XRD. In this regard, the effects of the calcination temperature of the waste Salmon fish bone, KOH loading amount, and the calcination temperature of KOH-impregnated support upon the catalytic activity of the final catalyst were understudied.... 

Three Keggin-type heteropolyacids were impregnated upon halloysite to produce heterogeneous acidic catalysts for synthesizing 5-hydroxymethylfurfural (5-HMF). Comparing the effectiveness of variously prepared catalysts in producing 5-HMF from fructose revealed the important role of halloysite in the final catalyst's acidic properties and performance in the reaction of halloysite-supported silicotungstic acid. Adjusting the reaction parameters for obtaining optimal results for the catalyst of choice was conducted via Response Surface Methodology and it was found that use of catalyst with 11 wt% active ingredient at 125 °C in DMSO solvent yielded the target compound with 99.5% after 43 min.... 

In this research, an appreciable Hal′@MIL-PMA photocatalyst was prepared through a hydrothermal approach to photo-oxidize Tetracycline. The as-fabricated composite was diagnosed by multiple catalyst characterization tests, including XRD, FTIR, FESEM, PL, EIS, EDS, TGA, BET, and DRS techniques. Under optimized conditions (i.e.; a 1 g/L dosage of photocatalyst, antibiotic concentration of 40 mg/L, pH = 7 and at ambient temperature), 97.11% of Tetracycline elimination was achieved by the pristine Hal′@MIL-PMA photocatalyst. Kinetics computation revealed that the photo-degradation rate of Tetracycline obeys the pseudo-first-order model. Tests on radical trapping manifested that hydroxyl radical... 

The synthesis of diamino triphenyl methanes from aniline and aromatic aldehydes was conducted in near critical water and supercritical water. The reaction parameters, such as temperature, density, and reaction time, have been studied. Significant acceleration of the condensation reaction of aniline and aromatic aldehydes can be achieved by using high temperature water, especially near the critical point, in the absence of any acid catalysts. It has been demonstrated that high temperature water act effectively in the place of conventional acid catalysts  

By a single-step supercritical hydrothermal synthesis method, yttrium oxide nanoparticles were successfully prepared without additional treatment. Yttrium oxide nanoparticles were employed as an adsorbent to study the adsorption of some heavy metal ions. This study revealed that nano structure yttrium oxide was an effective adsorbent for removal of lead ions from aqueous solutions  

A simple, efficient, and practical procedure for the synthesis of imidazo[1,2-a]quinoline and quinolino[1,2-a]quinazoline derivatives using CuO nanoparticles as a novel catalyst in excellent yields is described. The catalyst can be recovered conveniently and reused at least four times without any loss of activity  

A novel efficient and cost-effective heterogeneous catalyst for the production of biodiesel from transesterification of sunflower oil was prepared through the impregnation of K2CO3 upon the Talc material. The physicochemical features of the catalyst were studied through several characterization analyses. The effect of the K2CO3 loading was investigated by comparing the catalytic activity of various prepared catalysts. Moreover, the effect of the calcination temperature upon the catalytic activity was examined. To maximize the yield of the produced biodiesel fuel, reaction variables such as the reaction time and temperature, catalyst concentration, and methanol: oil molar ratio were... 

Hand in hand with the flourish of the biodiesel industry, glycerol (GLY) as an inconvenient by-product has generated environmental and sustainability concerns. Devising measures for efficient transformation of GLY into value-added products is a promising solution. In this contribution, the transformation of GLY to lactic acid (LA) as a valuable chemical was investigated in a continuous process for industrial applications. In this regard, a catalytic method using heterogeneous Cu nanoparticles in NaOH solution was studied in a microreactor by a CFD simulation. A seven-inlet micromixer comprising an optimized mixing unit was incorporated for uniform distribution of the species. The effects of... 

A new magnetic, catalytic nanocomposite of Hal-MT-Cys-Ag/MNCD was fabricated and utilized for catalyzing reductive de-colorization of methyl orange and rhodamin B in aqueous media at room temperature. To prepare this material, Cl-functionalized halloysite nanoclay was successively reacted with melamine and 2,4,6-trichloro-1,3,5-triazine to furnish multi-nitrogen containing ligand on halloysite surface. Then, magnetic carbon dots were crafted through a facile method and decorated with Ag nanoparticles and cysteine to furnish Cys-Ag/MNCD species. The final nanocomposite was obtained via incorporation of this latter species onto functionalized halloysite. This new composite was characterized... 

Structural flexibility and soil nonlinearity have important effects on the rocking performance of structures. However, there are a limited number of studies taking into account the consequences of these attributes simultaneously. This paper presents a comprehensive parametric study performed to explore the key parameters affecting the behavior of deformable rocking systems lying on compliant soil. The results illustrated that an increase in pulse motion amplitude and pulse motion period typically increases residual settlement and rotational amplitude. Finally, the performance of a relatively stiff rocking system with two different slenderness ratios was correlated to well-known intensity... 

A cost-effective and recyclable catalyst, K2CO3 supported on calcined salmon fish bone (K2CO3/SFB), was synthesized using an ultrasonic-assisted wet impregnation method. Various characterization techniques, including XRD, XPS, BET, FESEM, TGA, and FT-IR, were used to analyze the prepared catalysts. The catalytic efficiency of the sonicated K2CO3/SFB catalysts was evaluated in the transesterification reaction between Castor oil and methanol to produce biodiesel. The study also investigated the impact of calcination temperature and K2CO3 loading on the catalyst's performance, revealing that the highest catalytic activity was achieved with K2CO3 calcined at 773 K with a loading of 20 wt%.... 

The current study aimed at application of the plain and supported platinum nanoparticles as a heterogenous catalyst for the reduction of aromatic nitro compounds. Monodispersed platinum nanoparticles were synthesized by reduction of H2PtCl6 by ethanol in the presence of polyvinyl pyrrolidone as a stabilizer, and then were immobilized on four types of zeolites. The obtained catalyst granules were characterized by X-ray diffractometry and transmission electron microscopy. The study then focused on elaboration of the catalytic activity of the nano catalysts under different operational conditions. It was found that reaction is adequately rapid at ambient temperature, and by utilizing a...