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Full-Text Articles in Catalysis and Reaction Engineering

Electrochemically Active Biofilm Assisted Synthesis Of Ag@Ceo2 Nanocomposites For Antimicrobial Activity, Photocatalysis And Photoelectrodes, Mohammad Mansoob Khan Dr, S. A. Ansari, J. H. Lee, M. O. Ansari, J Lee, M. H. Cho Sep 2014

Electrochemically Active Biofilm Assisted Synthesis Of Ag@Ceo2 Nanocomposites For Antimicrobial Activity, Photocatalysis And Photoelectrodes, Mohammad Mansoob Khan Dr, S. A. Ansari, J. H. Lee, M. O. Ansari, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Ag@CeO2 nanocomposites were synthesized by a biogenic and green approach using electrochemically active biofilms (EABs) as a reducing tool. The as-synthesized Ag@CeO2 nanocomposites were characterized and used in antimicrobial, visible light photocatalytic and photoelectrode studies. The Ag@CeO2 nanocomposites showed effective and efficient bactericidal activities and survival test against Escherichia coli O157:H7, and Pseudomonas aeruginosa. The as-synthesized Ag@CeO2 nanocomposites also exhibited enhanced visible light photocatalytic degradation of 4-nitrophenol and methylene blue than pure CeO2. A photocatalytic investigation showed that the Ag@CeO2 nanocomposites possessed excellent visible light photocatalytic activities compared to pure CeO2. Electrochemical impedance spectroscopy and photocurrent measurements showed that the …


Au@Tio2 Nanocomposites For The Catalytic Degradation Of Methyl Orange And Methylene Blue: An Electron Relay Effect, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho Aug 2014

Au@Tio2 Nanocomposites For The Catalytic Degradation Of Methyl Orange And Methylene Blue: An Electron Relay Effect, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Au@TiO2 nanocomposites were used for the catalytic degradation of methyl orange and methylene blue by NaBH4. A detail pathway for step by step reduction, oxidation and complete mineralization of intermediates into the respective end-products was established by UV-vis spectroscopy, chemical oxygen demand, ion chromatography and cyclic voltammetry (CV). CV studies confirmed that the dyes were reduced and oxidized to the end-products by NaBH4 in the presence of Au@TiO2 nanocomposites and O2•, •OH and HO2• radicals generated in-situ. Results suggest that Au@TiO2 nanocomposites not only assist in the decolorization of dyes, but also promote their complete mineralization into harmless end-products.


Highly Visible Light Active Ag@Zno Nanocomposites Synthesized By Gel-Combustion Route, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho Aug 2014

Highly Visible Light Active Ag@Zno Nanocomposites Synthesized By Gel-Combustion Route, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Highly visible light active 1% and 3% Ag@ZnO nanocomposites were synthesized via a gel combustion route using citric acid as a fuel. The formation of the nanocomposites with enhanced properties was confirmed using a range of characterization techniques, photocatalysis and photoelectrochemical studies. Compared to the pristine ZnO nanoparticles, the Ag@ZnO nanocomposites exhibited enhanced visible light photocatalytic activity for the degradation of methylene blue and photoelectrochemical response. A mechanism was proposed to account for the photocatalytic activities of the Ag@ZnO nanocomposite that showed the surface plasmon resonance (SPR) of Ag is an effective way of enhancing the visible light photocatalytic activities.


Band Gap Engineering Of Ceo2 Nanostructure Using An Electrochemically Active Biofilm For Visible Light Applications, S A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho Apr 2014

Band Gap Engineering Of Ceo2 Nanostructure Using An Electrochemically Active Biofilm For Visible Light Applications, S A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Narrowing the optical band gap of cerium oxide (CeO2) nanostructures is essential for visible light applications. This paper reports a green approach to enhance the visible light photocatalytic activity of pure CeO2 nanostructures (p-CeO2) through defect-induced band gap narrowing using an electrochemically active biofilm (EAB). X-ray diffraction, UV-visible diffuse reflectance/absorption spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, Raman spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy confirmed the defect-induced band gap narrowing of the CeO2 nanostructure (m-CeO2). The structural, optical, photocatalytic and photoelectrochemical properties also revealed the presence of structural defects caused by the reduction of Ce4+ to …


Highly Photoactive Sno2 Nanostructures Engineered By Electrochemically Active Biofilm, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho Feb 2014

Highly Photoactive Sno2 Nanostructures Engineered By Electrochemically Active Biofilm, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports the defect-induced band gap narrowing of pure SnO2 nanostructures (p-SnO2) using an electrochemically active biofilm (EAB). The proposed approach is biogenic, simple and green. Systematic characterization of the modified SnO2 nanostructures (m-SnO2) revealed EAB-mediated defects in pure SnO2 nanostructures (p-SnO2). m-SnO2 nanostructures in visible light showed the enhanced photocatalytic degradation of p-nitrophenol and methylene blue compared to p-SnO2 nanostructures. Photoelectrochemical studies, such as electrochemical impedance spectroscopy and linear scan voltammetry, also revealed a significant increase in the visible light response of m-SnO2 compared to p-SnO2 nanostructures. The enhanced activities of m-SnO2 in visible light was attributed to …


Band Gap Engineered Tio2 Nanoparticles For Visible Light Induced Photoelectrochemical And Photocatalytic Studies, Mohammad Mansoob Khan Dr, S A. Ansari, D Pradhan, D H. Han, J Lee, M. H. Cho Dec 2013

Band Gap Engineered Tio2 Nanoparticles For Visible Light Induced Photoelectrochemical And Photocatalytic Studies, Mohammad Mansoob Khan Dr, S A. Ansari, D Pradhan, D H. Han, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Visible light-active TiO2 (m-TiO2) nanoparticles were obtained by an electron beam treatment of commercial TiO2 (p-TiO2) nanoparticles. The m-TiO2 nanoparticles exhibited a distinct red-shift in the UV-visible absorption spectrum and a much narrower band gap (2.85 eV) due to defects as confirmed by diffuse reflectance spectroscopy (DRS), photoluminescence (PL), X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and linear scan voltammetry (LSV). The XPS revealed changes in the surface states, composition, Ti4+ to Ti3+ ratio, and oxygen deficiencies in the m-TiO2. The valence band XPS, DRS and PL results were …


Optimization Of Gold Nanoparticles Synthesis By Stainless Steel For H2o2 And Glucose Detection, T. H. Han, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho Sep 2013

Optimization Of Gold Nanoparticles Synthesis By Stainless Steel For H2o2 And Glucose Detection, T. H. Han, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The synthesis of (+)AuNPs procedure using a stainless-steel mesh was optimized. The optimal synthetic parameters were found to be one piece of stainless-steel mesh (22.5 cm2 in surface area) in 100 mL of a 1 mM precursor, precursor solution pH 4, and reaction temperature of 30°C. Under the optimal conditions, the as-synthesized (+)AuNPs were highly positively charged (+24.2 mV). Therefore, the as-synthesized (+)AuNPs act as a peroxidase mimic and provide a simple, fast, highly sensitive and selective colorimetric method for H2O2 detection with a detection limit of 0.06 mM in the linear range from 0.06 mM to 4.29 mM.


Novel Ag@Tio2 Nanocomposite Synthesized By Electrochemically Active Biofilm For Nonenzymatic Hydrogen Peroxide Sensor, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho Jul 2013

Novel Ag@Tio2 Nanocomposite Synthesized By Electrochemically Active Biofilm For Nonenzymatic Hydrogen Peroxide Sensor, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

A novel nonenzymatic sensor for H2O2 was developed based on an Ag@TiO2 nanocomposite synthesized using a simple and cost effective approach with an electrochemically active biofilm. The optical, structural, morphological and electrochemical properties of the as-prepared Ag@TiO2 nanocomposite were examined by UV-vis spectroscopy, x-ray diffraction, transmission electron microscopy and cyclic voltammetry (CV). The Ag@TiO2 nanocomposite was fabricated on a glassy carbon electrode (GCE) and their electrochemical performance was analyzed by CV, differential pulse voltammetry and electrochemical impedance spectroscopy. The Ag@TiO2 nanocomposite modified GCE (Ag@TiO2/GCE) displayed excellent performance towards H2O2 sensing at −0.73 V in the linear response range from 0.83 …


Simultaneous Enhancement Of The Methylene Blue Degradation And Power Generation In Microbial Fuel Cell By Gold Nanoparticles, Mohammad Mansoob Khan Dr, T. H. Han, S. Kalathil, J. Lee, M. H. Cho May 2013

Simultaneous Enhancement Of The Methylene Blue Degradation And Power Generation In Microbial Fuel Cell By Gold Nanoparticles, Mohammad Mansoob Khan Dr, T. H. Han, S. Kalathil, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This study examined the effect of positively charged gold nanoparticles ((+)AuNPs) on the enhancement of methylene blue (MB) degradation in microbial fuel cell (MFC) cathode. The maximum electricity production of 36.56 mW/m2 and complete MB degradation were achieved simultaneously. The MFC performance and MB degradation are strictly dependent on cathodic conditions, such as N2 bubbling, air bubbling and addition of H2O2. MB was reduced rapidly under anaerobic condition, whereas complete oxidative mineralization of MB occurred in the presence of dissolved oxygen (DO) or H2O2. (+)AuNPs enhanced the electricity generation in the MFCs involving MB degradation owing to its electron relay …


Band Gap Narrowing Of Titanium Dioxide (Tio2) Nanocrystals By Electrochemically Active Biofilm And Their Visible Light Activity, S. Kalathil, Mohammad Mansoob Khan Dr, Sajid A. Ansari, M. H. Cho, J. Lee May 2013

Band Gap Narrowing Of Titanium Dioxide (Tio2) Nanocrystals By Electrochemically Active Biofilm And Their Visible Light Activity, S. Kalathil, Mohammad Mansoob Khan Dr, Sajid A. Ansari, M. H. Cho, J. Lee

Dr. Mohammad Mansoob Khan

We report a simple biogenic-route to narrow the band gap of TiO2 nanocrystals for visible light application by offering a greener method. When an electrochemically active biofilm (EAB) was challenged with a solution of Degussa-TiO2 using sodium acetate as electron donor, greyish blue-colored TiO2 nanocrystals were obtained. Band gap study showed that band gap of the modified TiO2 nanocrystals was significantly reduced (Eg = 2.85 eV) compared to the unmodified white Degussa TiO2 (Eg = 3.10 eV).