Sajjad Keshipour

Urmia University · Nanotechnology Research Center

Using water as a renewable and safe energy source for hydrogen generation has reduced the need to use toxic fossil fuels. Photocatalytic approaches provide a worthy solution to avoid the high expenditure on complicated electrochemical pathways to promote Hydrogen Evolution Reactions. However, several types of photocatalysts including noble metal-ba...

To precise screening concentration of ascorbic acid (AA), a novel electrochemical sensor was prepared using palladium nanoparticles decorated on nitrogen-doped graphene quantum dot modified glassy carbon electrode (PdNPs@N-GQD/GCE). For this purpose, nitrogen doped GQD nanoparticles (N-GQD) were synthesized from a citric acid condensation reaction...

Having high energy content, green nature, and abundant sources for the generation, hydrogen would be a promising fuel for the growing populations of mankind societies. Remarkable efforts have been doing to achieve simple, fast, and inexpensive approaches for the generation of hydrogen. Amongst them, photocatalytic water splitting has gained signifi...

Water splitting is considered one of the worthy approaches to generate hydrogen as a green fuel with diverse applications. Promoting this reaction with the photocatalytic strategy enjoys a free source of solar energy, without the use of expensive instruments. In this research, gold nanoparticles and cobalt(II)-phthalocyanine were deposited on nitro...

The environmental pollution crisis created by the fossil fuels pushes industries to find an alternative clean energy source to save the future of the world. Amongst candidates, hydrogen is considered as an invaluable fuel due to the easy production, high energy content, and getting burned in a green pathway. This report highlights hydrogen generati...

Biopolymer-based catalysts like chitosan, chitin, and cellulose offer sustainability and high efficiency both as the catalyst or catalyst support in a broad range of applications, especially in hydrogen evolution reactions. This review focused on hydrogen evolution catalysts of chitosan, chitin, cellulose, and carbon materials obtained from these b...

Herein, Co(II) citrate complex nanoparticles (CoC NPs) were synthesized by a simple protocol and were subsequently immobilized on GO sheets to provide a binary nanocomposite termed as CoC/GO. By conducting direct pyrolysis of citric acid (CA) in the presence of CoC NPs, the self-condensation reaction of CA facilitated in situ construction of the GO...

Hydrogen gas has attracted a great deal of attention as a fuel due to its non-polluting combustion reaction. A wide variety of approaches have been employed to generate this green fuel with a remarkable concentration on photocatalytic pathways, in which a free source of energy is consumed for hydrogen evolution. Accordingly, we focused on construct...

Abstract Water splitting has been widely studied since the reaction affords hydrogen as an energetic pollutant‐free fuel from the most abundant molecule. Electrolysis, and photolysis of water are reliable pathways for hydrogen generation in green conditions, in which a catalyst is in charge of the transformation, and manipulation of its structure p...

Water as an abundant and safe source has been employed for the hydrogen generation to cutback use of toxic fossil fuels. Promotion of this reaction by photocatalytic approaches is worthy solution to stay away from expenditure of complicated electrochemical pathways. Amongst photocatalysts, noble metal-based catalysts are widely utilized in this rea...

The electrochemical and photochemical properties of graphene derivatives could be significantly improved by modifications in the chemical structure. Herein, reduced graphene oxide (RGO) was functionalized with l-arginine (l-Arg) by an amidation reaction between the support and amino acid. Deposition of a powerful ligand, l-Arg, on the optically act...

Detection of heavy transition metals is of importance protecting humans and the environment from their toxicity. Amongst them, copper(II) and cobalt(II) need more attention due to their wide applications in industry, in which exposures with excess amounts of them cause heathy concerns. Hence, fast and efficient distinguishing copper(II) and cobalt(...

Hydrogen, the most abundant element in the universe, holds a great promise as an alternative to conventional fuels. Among various approaches, the renewable energy-driven electro- and photocatalytic generations have lately gained prominence owing to the plethora of advantages that they offer. It is evident that when employing these methods for the H...

Disadvantages of fossil fuels encourage researchers to develop clean combustion sources, in particular, H2 due to the high potential energy and safe by-products. Herein, Au was deposited on S-doped graphene quantum dots to obtain a heterogeneous photocatalyst for the degradation of formic acid toward H2 generation. Insertion of thiol groups on grap...

While one of the valuable approaches to obtain a heterogeneous catalyst is the supporting them on a high surface area supports, strategy mainly suffers from the low number of chelating agents on most of the supports to grip the metal cations catalysts. Therefore, loading multidentate compounds susceptible to bind with metal cations is a potent stra...

Manipulation of materials is considered as one of the eminent strategies to create desirable catalysts. In this regard, increasing surface area and decreasing dimensions of catalysts have been widely employed on account of effectiveness of these methods. Herein, aerogel form of chitosan as a sustainable, and high aspect ratio compound is employed a...

Interest in cost-effective materials pushes researchers to the inexpensive and abundant semiconductors to use photons’ energy for generating electrons and holes required for photocatalytic transformations. At the same time, polysilicon is one of the economic semiconductors with a disadvantage of high bandgap which could be solved by carbon-doping....

Hydrogen is among the most commonly discussed types of novel energies since it generates high energy in a green manner. Thus, hydrogen production under visible light has been studied with a novel hybrid catalyst including copper(II) phthalocyanine (CuPc) supported on graphene oxide (GO) and TiO2 in a pathway involving formic acid degradation. The h...

Herein, a new catalyst is prepared by covalent functionalization of graphene quantum dot with D-penicillamine (GQD-DPA). The successful functionalization and synthesis of GQD-DPA approved by different characterization methods and resultant GQD-DPA applied as an electrode modifier for preparation of Pb2+ electrochemical sensor. The GQD-DPA-modified...

A new photocatalytic system was introduced to degrade formic acid toward hydrogen production using nickel(II) phthalocyanine (NiPc)@graphene oxide (GO)/TiO 2 as the catalyst. Synthesis of NiPc was performed in the presence of GO leading to a homogeneous distribution of NiPc on GO. While TiO 2 promoted the reaction using each of NiPc and GO under vi...

A novel nanomaterial is synthesized based on the functionalization of graphene quantum dot with dimercaprol (GQD-DMC). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (TEM) are used to approve the successful synthesis of GQD-DMC. The synthesized nanomaterial is...

A new heterogeneous photocatalytic system including gold nanoparticles supported on TiO2 and reduced graphene oxide was introduced for the oxidation of alcohols and alkylarenes. The composite photocatalytically accelerated aerobic oxidation of alcohols and alkylarenes to the corresponding aldehydes and ketones in solvent-free conditions at room tem...

A new photocatalytic system was introduced to degrade formic acid toward hydrogen production using nickel(II) phthalocyanine (NiPc)@graphene oxide (GO)/TiO 2 as the catalyst. Synthesis of NiPc was performed in the presence of GO leading to a homogeneous distribution of NiPc on GO. While TiO 2 promoted the reaction using each of NiPc and GO under vi...

Objectives: This study aimed to evaluate the thermal stability and monomer elution of bulk fill composite resins cured at different irradiation distances. Materials and Methods: Forty cylindrical-shaped (3×4mm) specimens were fabricated from two composite resins (X-tra fil, X-tra base) and cured from 0 and 7mm distances. In 9 specimens, the degree...

Synthesis of new natural polymers-based nanocomposites is the center of attentions for the catalyst researchers on account of their sustainability. In this regard, cellulose aerogel was hydrophobized by polysilicon to give a hydrophobic bio-support which underwent deposition of TiO2 nanoparticles afforded a catalyst with high lipophilicity, superio...

A new heterogeneous catalyst was obtained by growing graphene quantum dots on chitosan and subsequent immobilization of Pd nanoparticles. The catalyst after characterization was used in the reduction of nitroarenes to the corresponding amines by NaBH4 as a weak reducing agent of nitro compounds. The catalyst exhibited excellent catalytic activity a...

The current research presents a very simple method for the colorimetric detection of imidacloprid using a graphene quantum dot/Au (III) chemosensor. The results demonstrated that there is an interaction between Au3+ ions and the imidazole group of the pesticide toward reduction of Au3+ to Au0 in the presence of graphene quantum dots. This phenomeno...

A new colorimetric sensor was designed for the screening pH changes in solutions, as well as, detection of some cations. The sensor preparation includes the chemical binding of alizarine red S (ARS) as a sensor of pH and cation to graphene quantum dots (GQD). Loading ARS on GQD led to the formation of water soluble sensor which finally responded to...

Application of Lemna gibba L. and a bio-based aerogel for the removal of metal(loid)s from stream waters near three gold deposits in northwestern Iran ABSTRACT Mining activities can be regarded as one of the main reasons for heavy metals pollution in the environment. In the present study, the capability of duckweed (Lemna gibba L.) and a modified c...

The purpose of this research is to investigate the residues of imidacloprid and penconazole in cucumbers, since pesticides have been highly demanded in the production of greenhouse crops. According to Codex Alimentarius Commission statement, the maximum residue limits (MRLs) for imidacloprid and penconazole in cucumber are 1 and 0.06 mg kg−1, respe...

The cover image is based on the Full Paper Synthesis and catalytic application of Pd/PdO/Fe3O4@polymer‐like graphene quantum dots by Sajjad Keshipour and Amal Al‐Azmi. Cover image © Sajjad Keshipour Images. https://doi.org/10.1002/aoc.5311.

Ru(III)/dimaval was deposited on chitosan aerogel through the ionic interactions of the proton exchange between the dimaval sulfonic acid and chitosan aerogel amine group. After characterization, the composite was used in the oxidation reaction of certain alkylarenes, aliphatic and benzylic alcohols as well as cyclohexanol. High conversions and exc...

A novel approach was achieved for growing citric acid towards polymer‐like graphene quantum dots (PGQD) with high efficiency in the presence of sodium hydroxide as a base catalyst. This protocol is completely safe, simple, fast, and efficient by a bottom up strategy. Thermal treatment of a mixture containing citric acid with NaOH at 300 °C gave PGQ...

Palladium(II) phthalocyanine (PdPc) tetrasulfonate was chemically bonded to an amine moiety of chitosan aerogel. The reaction was promoted by the transformation of sulfonic acid groups of PdPc to sulfonyl chloride, which is highly active for amination. The porous composite showed good catalytic activity in the oxidation reaction of some alkylarenes...

Novel hydrophobic cellulose aerogel (CA) supported graphene quantum dots (GQD)/Pd were synthesized with high lipophilicity, superior porosity as well as high catalytic activity. The nanocomposite aerogel was obtained in four steps, including transformation of cotton to CA, a silanization reaction of CA in the presence of TiO2 nanoparticles to give...

Phthalocyanines of Fe(II) and Ni(II) were immobilized on microcrystalline cellulose (MCC) via chemical binding. MCC was obtained from cotton as a cheap and abundant source of cellulose. The new composites were characterized by FT-IR, Flame Absorption Atomic Spectroscopy, Brunauer–Emmett–Teller analysis, Energy Dispersive X-ray Spectroscopy, Scannin...

A facile and fast strategy has been employed to fabricate Pd nanoparticles supported on TiO2 nanotubes/Ti plate via sonochemical deposition. Microstructure studies showed the homogeneous deposition of Pd nanoparticles on the walls of TiO2 nanotubes/Ti plate. The synthesized plate was applied as a novel catalyst for the oxidation of benzyl alcohol a...

کاتالیزور ناهمگنی از نانوکامپوزیت سلولز تهیه، شناسایی و برای اکسایش کاتالیزوری اتیل بنزن به استوفنون استفاده شد. نانوکامپوزیت سلولز از طریق اصلاح سلولز با نقاط کوانتومی گرافن دوپه شده با نیتروژن و ترسیب نانوذرات پالادیم بر روی آن سنتز شد. این کاتالیزور برای واکنش اکسایش اتیل بنزن در دمای محیط با استفاده از پتاس و اکسنده ی سبز هیدروژن پراکسید با ب...

Dimercaprol as the chelating agent of Au(III) was loaded on chitosan aerogel. Dimercaprol supported on chitosan aerogel efficiently was complexed with Au(III). The new organometallic compound showed good catalytic activity in the oxidation reaction of some aliphatic alcohols, benzyl alcohol, and ethylbenzene. High conversions and excellent selectiv...

A novel electrochemical sensor based on D-penicillamine anchored nano-cellulose (DPA-NC) modified pencil graphite electrode was fabricated and used for highly selective and sensitive determination of copper (II) ions in the picomolar concentration by square wave adsorptive stripping voltammetric (SWV) method. The modified electrode showed better and...

A new derivative of cellulose aerogel was prepared via functionalization of cellulose with dimercaprol. Dimercaprol, as a chelating agent of Au(III), was applied for the loading of Au(III) on cellulose aerogel. The new organogold compound after characterization was used as an efficient heterogeneous catalyst in the oxidation reactions of aliphatic...

Pd and Co nanoparticles were deposited on cellulose for use as a heterogeneous catalyst in the bimetallic catalytic reduction reaction. The catalyst was characterized with Energy Dispersive X-Ray Spectroscopy, X-Ray Diffraction pattern, Thermal Gravimetric Analysis, Flame Atomic Absorption Spectroscopy, and Transmission Electron Microscopy, and app...

A new efficient heterogeneous catalyst was introduced for the epoxidation of styrene. The catalyst was obtained from functionalization of graphene oxide nano-sheets with d-penicillamine, and then complexation of graphene oxide functionalized d-penicillamine with Co(II). High yield and excellent selectivity were achieved for the epoxidation of styre...

A new efficient heterogeneous catalyst was introduced for the epoxidation of styrene. The catalyst was obtained from functionalization of cellulose with N-(2-aminoethyl)acetamide, and then deposition of nanoparticles and Pd(0) nanoparticles on the modified cellulose. The Fe3O4 nanoparticles were deposited via chemical oxidation in basic media and P...

A new efficient heterogeneous catalyst is introduced for the oxidation of ethylbenzene. The catalyst was obtained in three steps: functionalization of cellulose with d-penicillamine, deposition of Fe3O4 nanoparticles on cellulose–d-penicillamine and then anchoring of Co(II) to the magnetic cellulose–d-penicillamine. High yield and excellent selecti...

A new derivative of chitosan was prepared via a chemical modification process which included chemical bonding of chitosan with d-penicillamine and anchoring of Pd(II) to the chitosan-d-penicillamine. Chitosan-modified Pd(II)-d-penicillamine was characterized by FT-IR, CHNS analysis, flame absorption atomic spectroscopy, energy dispersive X-ray spec...

A new efficient heterogeneous catalyst was introduced for the epoxidation of styrene. The catalyst was obtained from deposition of gold nanoparticles on the cellulose aerogel. The catalyst was characterized with XRD, TGA, EDX, BET, FAAS and SEM. High yield and excellent selectivity were achieved for the epoxidation of styrene in solvent-free condit...

A new support for Pd(II) was synthesized via the functionalization of Fe3O4 nanoparticles with N-(2-aminoethyl)acetamide. PdCl2 was anchored to the support for obtaining a heterogeneous magnetically recoverable catalyst for Pd(II). High yield and excellent selectivity were obtained for the green epoxidation of styrene derivatives using H2O2 as a gr...

Palladium and Fe3O4 nanoparticles were deposited on N-(2-aminoethyl)acetamide-functionalized cellulose for use in a catalytic reaction. The catalyst was characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, energy-dispersive X-ray analysis and transmission electron microscopy, and applied in the...

A new efficient catalyst was introduced for the green reduction of nitroaromatics. The catalyst was obtained via modification of cellulose with N-doped graphene quantum dots and Pd nanoparticles. The new cellulose nanocomposite after characterization was applied as the catalyst in the reduction reaction of nitroaromatics using NaBH4 at room tempera...

A new highly selective and environment-friendly Wacker oxidation process employing PdCl2/Fe3O4 nanoparticles in H2O at 100 °C using H2O2 as an oxidant has been developed. This approach has some advantages such as copper free reaction conditions, green solvent, high yield, excellent selectivity and green oxidant.

A comparative study of the synthesis of new bis-spirooxindolopyrrolizidine(pyrrolidine) ring systems by the cycloaddition of azomethine ylides with a bischalcone is performed. The azomethine ylide was generated in two steps including the condensation of sarcosine or proline with isatin and decarboxylation of the produced intermediate.

A comparative study of the synthesis of new bis-spirooxindolopyrrolizidine(pyrrolidine) ring systems by the cycloaddition of azomethine ylides with a bischalcone is performed. The azomethine ylide was generated in two steps including the condensation of sarcosine or proline with isatin and decarboxylation of the produced intermediate.

A novel approach has been developed for the efficient synthesis of structurally diverse imidazochromen-4-ones via a three-component condensation reaction of 2-aminoazines and various isocyanides with 4-oxo-4H-chromene-3-carbaldehyde derivatives in the presence of p-TSOH/ZnCl 2 as the catalyst in methanol under reflux conditions for 48 h.

Cobalt(II) phthalocyanine covalently immobilized on cellulose as a heterogeneous catalyst was synthesized and characterized. The catalyst showed good catalytic activity for the aerobic oxidation of alkyl arenes and alcohols under relatively mild reaction conditions. The catalyst can readily be recovered from the reaction mixture and reused for seve...

Ethylenediamine-functionalized nanocellulose complexed with cobalt(II) was found to be a highly efficient heterogeneous catalyst for the room temperature aerobic oxidation of various types of primary and secondary benzylic alcohols into their corresponding aldehydes and ketones, respectively. The catalyst showed no significant loss of efficiency af...

Cu(I) and nanoparticles of Pd supported on ethylenediamine‐functionalized cellulose as a novel bio‐supported catalyst was synthesized and characterized. The synthesized catalyst was found to be a highly efficient heterogeneous catalyst for the synthesis of 1,4,5‐trisubstituted 1,2,3‐triazoles through a sustainable 1,3‐dipolar cycloaddition/direct a...

A novel protocol has been developed for the aerobic hydrolysis of nitriles to amides using cobalt(II)/zinc without using any strong acids and bases under solvent-free conditions. The reaction showed good performance for benzonitriles with sensitive groups such as ester and carboxylic acid.

A novel one-pot sequential four-component strategy has been developed for the synthesis of tetrahydroquinazolines using either an aliphatic or an acyl halide, an isocyanide, and a 1,3-diamine, in methanol at 60 degrees C, in good to moderate yields without using a catalyst.

Cu(I) and nanoparticles of Pd supported on ethylenediamine-functionalized cellulose as a novel bio-supported catalyst was synthesized and characterized. The synthesized catalyst was found to be a highly efficient heterogeneous catalyst for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles through a sustainable 1,3-dipolar cycloaddition/direct a...

Ethylenediamine-functionalized nanocellulose complexed with cobalt(II) was found to be a highly efficient heterogeneous catalyst for the room temperature aerobic oxidation of various types of primary and secondary benzylic alcohols into their corresponding aldehydes and ketones, respectively. The catalyst showed no significant loss of efficiency af...

Synthesis of seven-membered ring analogues of ketamine was studied with two strategies. In the first approach a sequence of five reactions was used which previously applied for ketamine synthesis. This strategy led to formation of 1-[(2-chlorophenyl)(methylimino)methyl]cyclohexan-1-ol as a precursor for the target molecule. In the second approach,...

Ethylenediamine-functionalized nanocellulose complexed with cobalt(II) was found to be a highly efficient heterogeneous catalyst for the room temperature aerobic oxidation of various types of primary and secondary benzylic alcohols into their corresponding aldehydes and ketones, respectively. The catalyst showed no significant loss of efficiency af...

Palladium nano-particles supported on ethylenediamine-functionalized cellulose as a novel bio-supported catalyst were synthesized and characterized. The synthesized catalyst was found to be a highly efficient heterogeneous catalyst for the Heck and Sonogashira couplings in H2O as a green solvent at 100 °C in very low loading of Pd. The catalyst cou...

We report herein the fabrication of a novel electrochemical sensor based on palladium nanoparticles immobilized on ethylenediamine cellulose which is consisted of uniformly distributed palladium nanoparticles with the main average size of 4.7–6.9 nm. The structure of the prepared nanocomposite was investigated by X-ray powder diffraction, transmiss...

A novel one-pot pseudo five-component reaction of isocyanides with 2,5-dihydroxycyclohexa-2,5-diene-1,4-dione and various aliphatic and aromatic aldehydes in ethanol at room temperature has been studied. 2,6-Bis(alkylamino)-benzofuro[5,6-b]furan-4,8-dione derivatives were isolated as the products in good yields after 24 h.

The 2,5-dihydroxy-1,4-benzoquinone-assisted oxy-Michael addition reaction between an aromatic aldehyde, EtOH and 2-naphthol or 6-hydroxyquinoline in the presence of HCl to afford the 1-[ethoxy(aryl)methyl]-2-naphthol and 5-[ethoxy(phenyl)methyl]-6-hydroxyquinoline derivatives at room temperature is described. Graphical abstract

Broader substrate scope, improved availability of the starting materials, ease of handling, simple work-up, and improvement of general yields are advantages over previously reported methods.

Chromenes as one of the privileged structures are a large group of naturally-occurring compounds with a wide range of biological activities and they are present abundant in the diet of humans due to their origin in plants [1]. The therapeutic applications of chromenes include tyrosine and protein kinase C inhibitors, antifungal, antiviral, antitubu...

a b s t r a c t A new protocol has been developed for the efficient synthesis of structurally diverse 1H-pyrazolo[1,2-b] phthalazine-1,2-dicarboxylates and 1H-pyrazolo[1,2-a]pyridazine-1,2-dicarboxylates via a four-component reaction of hydrazine hydrate, dialkyl acetylenedicarboxylates, isocyanides and various cy-clic anhydrides such as succinic a...

The zwitterionic intermediate generated from the reaction of triphenylphosphine with electron deficient acetylenic compounds was trapped by various NH acids. The synthesis resulted in a new class of highly functionalized heterocyclic compounds. Some of the reactions produced E and Z isomers. And the stability and transformation of them were studied...

An unexpected coupling reaction between isocyanides and carboxylic acids which led to the synthesis of highly stable symmetrical and unsymmetrical alkylamidine and arylamidine carbocations under mild reaction conditions is described. The structures of these compounds were confirmed by IR, mass, 1H NMR, 13C NMR, and single-crystal X-ray diffraction...

A new class of pyridinium, quinolinium, isoquinolinum, and N-methylimidazolium-3-(2,5-dihydro-5-oxofuran-3-yl)-4-hydroxyfuran-2(5H)-one salts have been prepared in high yields by reacting pyridine, quinoline, isoquinoline, N-methylimidazole, 1,4-diazabicyclo[2.2.2]octane, and their derivatives with tetronic acid in CH2Cl2.

A novel and efficient method has been developed for the synthesis of tetrahydro-2,4-dioxo-1H-benzo[b][1,5]diazepine-3-yl-2-methylpropanamide derivatives using an aromatic diamine, Meldrum's acid, and an isocyanide in CH(2)Cl(2) at ambient temperature in high yields without using any catalyst or activation. The procedure provides an alternative meth...

The three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylate and isocyanides with 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one is described. The reaction afforded the corresponding special type of fully substituted pyrano[2,3-c]pyrazole derivatives in good yields without using any catalyst and activation.