Anion selective <i>p</i>TSA doped polyaniline@graphene oxide-multiwalled carbon nanotube composite for Cr(VI) and Congo red adsorption

Ansari, Mohammad Omaish,Kumar, Rajeev,Ansari, Sajid Ali,Ansari, Shahid Pervez,Barakat, M.A.,Alshahrie, Ahmed,Cho, Moo Hwan Elsevier 2017 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.496 No.-

<P><B>Abstract</B></P> <P>Multiwalled carbon nanotube (CNT)-graphene oxide (GO) composite was combined with polyaniline (Pani) using an oxidative polymerisation technique. The resulting Pani@GO-CNT was later doped with para toluene sulphonic acid (<I>p</I>TSA) to generate additional functionality. The functional groups exposed on the GO, Pani and <I>p</I>TSA were expected to impart a high degree of functionality to the <I>p</I>TSA-Pani@GO-CNT composite system. The composite was characterised by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The characterisation results revealed the characteristics of Pani, GO, CNT, and <I>p</I>TSA, and suggested the successful formation of the <I>p</I>TSA-Pani@GO-CNT composite system. The composite was utilised successfully for the adsorptive removal of Cr(IV) and Congo red (CR) dye and the adsorption of both pollutants was found to be strongly dependent on the solution pH, adsorbate concentration, contact time, and reaction temperature. The maximum adsorption of Cr(IV) and CR was observed in an acidic medium at 30°C. The kinetics for Cr(IV) and CR adsorption was studied using pseudo-first order, pseudo-second order, and intraparticle diffusion models. The adsorption equilibrium data were also fitted to the Langmuir and Freundlich isotherm models. The thermodynamic results showed that the adsorption process was exothermic in nature. The present study provides a new methodology for the preparation of a highly functionalised Pani-based nanocomposite system and its potential applications to the adsorptive removal of a multicomponent pollutant system from an aqueous solution.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Protective effects of Hydro-alcoholic extract of the roots of Kasondi (Cassia occidentalis L.) against gentamicin-induced nephrotoxicity in albino Wistar rats

Jwariya Shamim(Jwariya Shamim ),Athar Parvez Ansari(Athar Parvez Ansari ),Pankaj Goswami(Pankaj Goswami ),Seema Akbar(Seema Akbar ),Huzaifa Ansari(Huzaifa Ansari ),Abdul Wadud(Abdul Wadud ),Pervaiz Ah 셀메드 세포교정의약학회 2023 셀메드 (CellMed) Vol.13 No.6

Objectives:Cassia occidentalis L. is a weed belonging to the Caesalpiniaceae family. The root of this medicinal plant is used for the treatment of various ailments, including kidney diseases. The present study was aimed at evaluating the nephroprotective effects of HAE of the roots of Cassia occidentalis L. against gentamicin-induced renal toxicity in albino Wistar rats. Methods:The renal toxicity was induced by subcutaneous administration of gentamicin at 100 mg/kg in the rats belonging to the disease control and treatment groups from the 4th to the 8th day. The rats in the treatment group received HAE of the roots of Cassia occidentalis L. at 67 mg/kg b. w. orally for 8 days, while no treatment was given to the rats in the disease control and plain control groups. At the end of the experiment, renal biomarkers viz; s. creatinine, b. urea, and s. uric acid, were investigated. The histopathological examination of the kidney specimens was also carried out. Results:The results of the present study revealed that renal function biomarkers such as s. creatinine, b. urea, and s. uric acid were significantly reduced in the rats of the treatment group as compared to those of the disease control group. Moreover, the histoarchitecture reports of the treatment group’s kidney specimens showed significant improvements. Conclusion:The results suggested that the HAE of Cassia occidentalis L. roots promisingly prevented kidney injury in gentamicin-induced nephrotoxic rats. This effect might be due to improved clearance of gentamicin from the renal tubule and decreased generation of reactive oxygen species (ROS).

Metal free earth abundant elemental red phosphorus: a new class of visible light photocatalyst and photoelectrode materials

Ansari, Sajid Ali,Ansari, Mohammad Shahnawaze,Cho, Moo Hwan The Royal Society of Chemistry 2016 Physical Chemistry Chemical Physics Vol.18 No.5

<P>Developing a high-performance photocatalyst and a photoelectrode with enhanced visible light harvesting properties is essential for practical visible light photocatalytic applications. Noble metal-free, highly visible light-active, elemental red phosphorus (RP) was prepared by a facile mechanical ball milling method, which is a reproducible, low cost and controllable synthesis process. The synthesis used inexpensive and abundant raw materials because most RP hybrids are based on expensive noble-metals. The novel milled RP showed significantly enhanced photocatalytic and photoelectrochemical performances with a lower charge transfer resistance compared to commercial RP under wide visible photoirradiation, making it a feasible alternative for photocatalytic applications.</P>

SUPERCYCLICITY OF ℓ^p-SPHERICAL AND TORAL ISOMETRIES ON BANACH SPACES

Ansari, Mohammad,Hedayatian, Karim,Khani-Robati, Bahram Korean Mathematical Society 2017 대한수학회논문집 Vol.32 No.3

Let $p{\geq}1$ be a real number. A tuple $T=(T_1,{\ldots},T_n)$ of commuting bounded linear operators on a Banach space X is called an ${\ell}^p$-spherical isometry if ${\sum_{i=1}^{n}}{\parallel}T_ix{\parallel}^p={\parallel}x{\parallel}^p$ for all $x{\in}X$. The tuple T is called a toral isometry if each Ti is an isometry. By a result of Ansari, Hedayatian, Khani-Robati and Moradi, for every $n{\geq}1$, there is a supercyclic ${\ell}^2$-spherical isometric n-tuple on ${\mathbb{C}}^n$ but there is no supercyclic ${\ell}^2$-spherical isometry on an infinite-dimensional Hilbert space. In this article, we investigate the supercyclicity of ${\ell}^p$-spherical isometries and toral isometries on Banach spaces. Also, we introduce the notion of semicommutative tuples and we show that the Banach spaces ${\ell}^p$ ($1{\leq}p$ < ${\infty}$) support supercyclic ${\ell}^p$-spherical isometric semi-commutative tuples. As a result, all separable infinite-dimensional complex Hilbert spaces support supercyclic spherical isometric semi-commutative tuples.

Highly photoactive SnO₂ nanostructures engineered by electrochemically active biofilm

Ansari, Sajid Ali,Khan, Mohammad Mansoob,Omaish Ansari, Mohd,Lee, Jintae,Cho, Moo Hwan The Royal Society of Chemistry 2014 NEW JOURNAL OF CHEMISTRY Vol.38 No.6

<P>This paper reports the defect-induced band gap narrowing of pure SnO<SUB>2</SUB> nanostructures (p-SnO<SUB>2</SUB>) using an electrochemically active biofilm (EAB). The proposed approach is biogenic, simple and green. The systematic characterization of the modified SnO<SUB>2</SUB> nanostructures (m-SnO<SUB>2</SUB>) revealed EAB-mediated defects in the pure SnO<SUB>2</SUB> nanostructures (p-SnO<SUB>2</SUB>). The modified SnO<SUB>2</SUB> (m-SnO<SUB>2</SUB>) nanostructures in visible light showed the enhanced photocatalytic degradation of <I>p</I>-nitrophenol and methylene blue compared to the p-SnO<SUB>2</SUB> nanostructures. The photoelectrochemical studies, such as the electrochemical impedance spectroscopy and linear scan voltammetry, also revealed a significant increase in the visible light response of the m-SnO<SUB>2</SUB> compared to the p-SnO<SUB>2</SUB> nanostructures. The enhanced activities of the m-SnO<SUB>2</SUB> in visible light was attributed to the high separation efficiency of the photoinduced electron–hole pairs due to surface defects mediated by an EAB, resulting in a band gap narrowing of the m-SnO<SUB>2</SUB> nanostructures. The tuned band gap of the m-SnO<SUB>2</SUB> nanostructures enables the harvesting of visible light to exploit the properties of the metal oxide towards photodegradation, which can in turn be used for environmental remediation applications.</P> <P>Graphic Abstract</P><P>This paper reports the defect-induced band gap narrowing of pure SnO<SUB>2</SUB> nanostructures (p-SnO<SUB>2</SUB>) using an electrochemically active biofilm (EAB). <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3nj01488f'> </P>

Mechanically exfoliated MoS₂ sheet coupled with conductive polyaniline as a superior supercapacitor electrode material

Ansari, Sajid Ali,Fouad, H.,Ansari, S.G.,Sk, Md Palashuddin,Cho, Moo Hwan Elsevier 2017 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.504 No.-

<P><B>Abstract</B></P> <P>The development of electrically conductive metal sulfide-based polymer nanocomposites for energy storage materials has been a major focus by researchers to solve the energy crisis. In this study, a simple and facile method was used to construct a nanocomposite by combining a mechanically exfoliated MoS<SUB>2</SUB> (M-MoS<SUB>2</SUB>) sheet with polyaniline (Pani) using a simple and scalable in-situ chemical oxidative polymerization method. The as-prepared nanocomposite (M-MoS<SUB>2</SUB>-Pani nanocomposite) was characterized further by usual basic spectroscopic techniques, such as X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller surface area analysis. The electrochemical supercapacitive characteristics of the M-MoS<SUB>2</SUB>-Pani nanocomposite was tested in a three-electrode assembly by obtaining cyclic voltammetric (CV) curves and galvanostatic charge-discharge (GCD) measurements. The results were compared with those of a C-MoS<SUB>2</SUB>-Pani nanocomposite that had been synthesized using bulk MoS<SUB>2</SUB>. The M-MoS<SUB>2</SUB>-Pani nanocomposite synthesized using exfoliated MoS<SUB>2</SUB> exhibited a higher specific capacitance of 510.12Fg<SUP>−1</SUP> at a current of 1Ag<SUP>−1</SUP> than the C-MoS<SUB>2</SUB>-Pani nanocomposite (225.15Fg<SUP>−1</SUP>), which was synthesized using bulk C-MoS<SUB>2</SUB> delivered. The enhanced electrochemical supercapacitive performance was correlated to the synergistic effect and chemical interactions between the Pani and MoS<SUB>2</SUB>, which provide high electrical conductivity and a sufficient empty state for electrode/electrolyte contact.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced thermoelectric performance and ammonia sensing properties of sulfonated polyaniline/graphene thin films

Ansari, M.O.,Khan, M.M.,Ansari, S.A.,Amal, I.,Lee, J.,Cho, M.H. North-Holland 2014 Materials letters Vol.114 No.-

Highly conducting nanocomposite film of polyaniline (Pani) with graphene (GN) was prepared by incorporating GN nanoplatelets in Pani matrix, followed by sulfonating it with fuming sulfuric acid. Sheet-like GN nanoplatelets were distributed uniformly in a Pani matrix, leading to high electrical conductivity due to π-π interaction between sulfonated Pani (s-Pani) and GN. Studies of the thermoelectrical behavior and ammonia-sensing behavior on GNσ-Pani showed high DC electrical conductivity retention under ageing conditions as well as excellent reproducible sensing response towards ammonia vapor in contrast to acid-protonated Pani.

Electrically conductive polyaniline sensitized defective-TiO₂ for improved visible light photocatalytic and photoelectrochemical performance: a synergistic effect

Ansari, Mohd Omaish,Khan, Mohammad Mansoob,Ansari, Sajid Ali,Cho, Moo Hwan The Royal Society of Chemistry 2015 NEW JOURNAL OF CHEMISTRY Vol.39 No.11

<P>Sulfonated polyaniline@pure-TiO<SUB>2</SUB> (s-Pani@p-TiO<SUB>2</SUB>) and polyaniline@defective-TiO<SUB>2</SUB> (s-Pani@m-TiO<SUB>2</SUB>) nanocomposites were prepared by the <I>in situ</I> oxidative polymerization of aniline in the presence of TiO<SUB>2</SUB> (p-TiO<SUB>2</SUB> and m-TiO<SUB>2</SUB>) nanoparticles followed by sulfonation with fuming sulfuric acid. Defect-induced TiO<SUB>2</SUB> (m-TiO<SUB>2</SUB>) nanoparticles were obtained by an electron beam (EB) treatment of commercial TiO<SUB>2</SUB> (p-TiO<SUB>2</SUB>) nanoparticles. The resulting s-Pani@p-TiO<SUB>2</SUB> and s-Pani@m-TiO<SUB>2</SUB> nanocomposites were characterized by UV-visible diffuse absorbance spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Polyaniline (Pani) was dispersed uniformly over the defective m-TiO<SUB>2</SUB> surface with intimate contact on the interface to act cooperatively with the deliberately induced defects to achieve remarkably enhanced properties. The s-Pani@m-TiO<SUB>2</SUB> nanocomposite showed better photocatalytic activity and photoelectrochemical performance than s-Pani@p-TiO<SUB>2</SUB> under visible light irradiation, which was attributed partly to the sensitizing effect of Pani, the narrowed band gap of m-TiO<SUB>2</SUB> and the effective interfacial interaction between Pani and m-TiO<SUB>2</SUB>. The electrical conductivity measured using a four-point probe revealed s-Pani@m-TiO<SUB>2</SUB> to have much higher conductivity than s-Pani@p-TiO<SUB>2</SUB>. Therefore, s-Pani@m-TiO<SUB>2</SUB> may be used for a wide range of applications owing to its higher charge mobility and high photocatalytic activity. The proposed methodology can also be a potential route for the development of nanocomposites <I>via</I> EB treatment and can be commercialized.</P> <P>Graphic Abstract</P><P>A proposed scheme for the synthesis of s-Pani@m-TiO<SUB>2</SUB> nanocomposites. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5nj01127b'> </P>

Enhanced Thermal Stability under DC Electrical Conductivity Retention and Visible Light Activity of Ag/TiO₂@Polyaniline Nanocomposite Film

Ansari, Mohd Omaish,Khan, Mohammad Mansoob,Ansari, Sajid Ali,Raju, Kati,Lee, Jintae,Cho, Moo Hwan American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.11

<P>The development of organic–inorganic photoactive materials has resulted in significant advancements in heterogeneous visible light photocatalysis. This paper reports the synthesis of visible light-active Ag/TiO<SUB>2</SUB>@Pani nanocomposite film via a simple biogenic–chemical route. Electrically conducting Ag/TiO<SUB>2</SUB>@Pani nanocomposites were prepared by incorporating Ag/TiO<SUB>2</SUB> in <I>N</I>-methyl-2-pyrrolidone solution of polyaniline (Pani), followed by the preparation of Ag/TiO<SUB>2</SUB>@Pani nanocomposite film using solution casting technique. The synthesized Ag/TiO<SUB>2</SUB>@Pani nanocomposite was confirmed by UV–visible spectroscopy, photoluminescence spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The Ag/TiO<SUB>2</SUB>@Pani nanocomposite film showed superior activity towards the photodegradation of methylene blue under visible light compared to Pani film, even after repeated use. Studies on the thermoelectrical behavior by DC electrical conductivity retention under cyclic aging techniques showed that the Ag/TiO<SUB>2</SUB>@Pani nanocomposite film possessed a high combination of electrical conductivity and thermal stability. Because of its better thermoelectric performance and photodegradation properties, such materials might be a suitable advancement in the field of smart materials in near future.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-11/am500488e/production/images/medium/am-2014-00488e_0013.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am500488e'>ACS Electronic Supporting Info</A></P>

Ammonia vapor sensing and electrical properties of fibrous multi-walled carbon nanotube/polyaniline nanocomposites prepared in presence of cetyl-trimethylammonium bromide

Ansari, M.O.,Ansari, S.P.,Yadav, S.K.,Anwer, T.,Cho, M.H.,Mohammad, F. Korean Society of Industrial and Engineering Chemi 2014 Journal of industrial and engineering chemistry Vol.20 No.4

Electrically conductive HCl-doped multi-walled carbon nanotube (MWCNT)/polyaniline (Pani) nanocomposites were prepared in the presence of cetyl-trimethylammonium bromide by in situ oxidative polymerization of aniline containing different amount of MWCNTs. Thus prepared Pani♂WCNT nanocomposites were characterized by FTIR, XRD, Raman spectroscopy, SEM and TEM. The stability in terms of their electrical conductivity retention was studied under isothermal and cyclic aging conditions. Pani♂WCNT nanocomposites showed increased thermal stability in terms of DC electrical conductivity retention with increasing MWCNT content. One of the Pani♂WCNT nanocomposites was also tested for ammonia sensing which showed good sensing response and high reproducibility.