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Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Spectroscopic And Physico-Chemical Characterization Of Ir(I) And Ru(Iii) Complexes Of 32-Membered Unsymmetrical Dinucleating Macrocyclic Ligand, Mohammad Mansoob Khan Dr Dec 2013

Spectroscopic And Physico-Chemical Characterization Of Ir(I) And Ru(Iii) Complexes Of 32-Membered Unsymmetrical Dinucleating Macrocyclic Ligand, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

No abstract provided.


Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho Dec 2013

Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of coupled photoactive materials (metal/semiconductor) has resulted in significant advancements in heterogeneous visible light photocatalysis. This work reports the novel biogenic synthesis of visible light active Ag–ZnO nanocomposite for photocatalysis and photoelectrode using an electrochemically active biofilm (EAB). The results showed that the EAB functioned as a biogenic reducing tool for the reduction of Ag+, thereby eliminating the need for conventional reducing agents. The as-prepared Ag–ZnO nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic experiments showed that the Ag–ZnO nanocomposite possessed excellent visible light photocatalytic activity …


Production Of Bioelectricity, Bio-Hydrogen, High Value Chemicals And 3 Bioinspired Nanomaterials By Electrochemically Active Biofilms, S. Kalathil, Mohammad Mansoob Khan Dr, M. H. Cho, J. Lee May 2013

Production Of Bioelectricity, Bio-Hydrogen, High Value Chemicals And 3 Bioinspired Nanomaterials By Electrochemically Active Biofilms, S. Kalathil, Mohammad Mansoob Khan Dr, M. H. Cho, J. Lee

Dr. Mohammad Mansoob Khan

Microorganisms naturally form biofilms on solid surfaces for their mutual benefits including protection from environmental stresses caused by contaminants, nutritional depletion or imbalances. The biofilms are normally dangerous to human health due to their inherited robustness. On the other hand, a recent study suggested that electrochemically active biofilms (EABs) generated by electrically active microorganisms have properties that can be used to catalyze or control the electrochemical reactions in a range of fields, such as bioenergy production, bioremediation, chemical/biological synthesis, bio-corrosion mitigation and biosensor development. EABs have attracted considerable attraction in bioelectrochemical systems (BESs), such as microbial fuel cells and microbial …


Highly Visible Light Active Ag@Tio2 Nanocomposites Synthesized By Electrochemically Active Biofilm: A Novel Biogenic Approach, Mohammad Mansoob Khan Dr, Sajid A. Ansari, J. Lee, M. H. Cho Mar 2013

Highly Visible Light Active Ag@Tio2 Nanocomposites Synthesized By Electrochemically Active Biofilm: A Novel Biogenic Approach, Mohammad Mansoob Khan Dr, Sajid A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Titanium dioxide (TiO2) nanoparticles were decorated with different amounts of silver nanoparticles (AgNPs) using an electrochemically active biofilm (EAB), which is a biogenic approach that leads to the formation of Ag@TiO2 nanocomposites. UV-vis spectroscopy, photoluminescence, x-ray diffraction and electron microscopy showed AgNPs, 2 - 5 nm in size, well-dispersed and anchored to the TiO2 surface and overall synthesis of Ag@TiO2 nanocomposites. The photocatalytic performance of the as-synthesized Ag@TiO2 nanocomposites was evaluated in terms of their efficiency for the photodecomposition of methylene blue (MB) in an aqueous solution under visible light irradiation. The nanocomposites showed exceptionally high photodecomposition efficiency (> 7 …


Electrochemically Active Biofilm Mediated Bio-Hydrogen Production Catalyzed By Positively Charged Gold Nanoparticles, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho Mar 2013

Electrochemically Active Biofilm Mediated Bio-Hydrogen Production Catalyzed By Positively Charged Gold Nanoparticles, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

An electrochemically active biofilm (EAB) was used for the synthesis of positively charged gold nanoparticles [(+)AuNPs] and in-situ hydrogen production without any external energy input. The EAB generate electrons and protons by decomposing sodium acetate (carbon source) in water at 30 C. These electrons were used initially to reduce Au3+ to Au0, and later in-situ, these generated electrons and protons were used for hydrogen produc-tion. The as-synthesized (+)AuNPs acted as catalyst by providing a charged surface to reduce the protons, leading to the formation of molecular hydrogen according to the Volmer-Heyrovsky mechanism. The hydrogen produced was confirmed and estimated by …


Enhanced Optical, Visible Light Catalytic And Electrochemical Properties Of Au@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, Sajid A. Ansari Mar 2013

Enhanced Optical, Visible Light Catalytic And Electrochemical Properties Of Au@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, Sajid A. Ansari

Dr. Mohammad Mansoob Khan

Au@TiO2 nanocomposites and pure TiO2 were successfully used to know the effect of Au on TiO2 and their comparative optical, visible light catalytic andelectrochemical activities were investigated. Optical parameters such as band gap energy (Eg = 2.4 eV), absorption coefficient (a), refractive index (n) and dielectric constants (s) have been determined using different methods. Visible light (590 nm) catalytic activity of Au@TiO2 nanocomposites was performed for reducing methyl orange (MO) under visible light irradiation. CV, EIS and DPV studies demonstrate that Au@TiO2 nanocomposites exhibit redox behavior, charged its surface by accumulating electrons, store and release the electrons.


Enhanced Performance Of A Microbial Fuel Cell Using Cnt/Mno2 Nanocomposites As A Bioanode Materials, S. Kalathil, A Hoa, J Shim, Mohammad Mansoob Khan Dr, J Lee, M H. Cho Jan 2013

Enhanced Performance Of A Microbial Fuel Cell Using Cnt/Mno2 Nanocomposites As A Bioanode Materials, S. Kalathil, A Hoa, J Shim, Mohammad Mansoob Khan Dr, J Lee, M H. Cho

Dr. Mohammad Mansoob Khan

The anode electrode material is a crucial factor for the overall performance of a microbial fuel cell (MFC). In this study, a plain carbon paper modified with the CNT/MnO 2 nanocomposite was used as the anode for the MFC and a mixed culture inoculum was used as the biocatalyst. The modified anode showed better electrochemical performance than that of plain carbon paper, and Brunauer Emmett Teller (BET) analysis showed the high surface area (94.6 m2/g) of the composite. The Mn4+ in the nanocomposite may enhance the electron transfer between the microorganisms and the anode material which facilitates electron conduction. Additionally, …


Synthesis Of Gold Nanoparticles Using A Stainless Steel Mesh, Thi Hiep Han, Mohammad Mansoob Khan Dr, S Kalathil, J Lee, M H. Cho Dec 2012

Synthesis Of Gold Nanoparticles Using A Stainless Steel Mesh, Thi Hiep Han, Mohammad Mansoob Khan Dr, S Kalathil, J Lee, M H. Cho

Dr. Mohammad Mansoob Khan

A novel, rapid, one-pot, and facile approach was developed to synthesize positively charged gold nanoparticles [(+) AuNPs] by employing an aqueous solution of HAuCl4·3H2O as a precursor at 30 °C and a stainless-steel mesh as a reducing agent. The penetration of Cl− ions into the stainless-steel surface results in corrosion on the stainless-steel surface and excretion of electrons which are used for reduction of Au3+ → Au0. As a result, (+) AuNPs 5-20 nm in size, mostly monodispersed, were synthesized within 3 h. The as-synthesized AuNPs were charaterized by UV-vis, DLS, XRD, TEM, HR-TEM, EDX and SAED. The utilization of …


Positively Charged Gold Nanoparticles Synthesized By Electrochemically Active Biofilm – A Biogenic Approach, Mohammad Mansoob Khan Dr, S. Kalathil, J. Lee, Moo Hwan Cho Dec 2012

Positively Charged Gold Nanoparticles Synthesized By Electrochemically Active Biofilm – A Biogenic Approach, Mohammad Mansoob Khan Dr, S. Kalathil, J. Lee, Moo Hwan Cho

Dr. Mohammad Mansoob Khan

Positively charged gold nanoparticles [(+) AuNPs] of 5-20 nm were synthesized by using electrochemically active biofilm (EAB) formed on a stainless steel mesh, within 30 minutes, in aqueous solution containing HAuCl4 as a precursor and sodium acetate as an electron donor. Electrochemically active bacteria present on biofilm oxidize the sodium acetate by producing electrons. Simultaneously, stainless steel also provides electrons because of the Cl− ions penetration into the stainless steel. Combined effect of both the EAB and stainless steel mesh enhances the availability of electrons for the reduction of Au3+ in the solution, which makes this synthesis efficient and fast. …