Chemistry Commons^™

Cobalt-Doped Ceria/Reduced Graphene Oxide Nanocomposite As An Efficient Oxygen Reduction Reaction Catalyst And Supercapacitor Material, Shaikh Parwaiz, Kousik Bhunia, Ashok Kumar Das, Mohammad Mansoob Khan Dr, Debabrata Pradhan

Dr. Mohammad Mansoob Khan

Editorial Of Special Issue: Nanomaterials As Photocatalysts, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

This thematic special issue entitled “Nanomaterials as Photocatalysts” based on selected research/review articles submitted to the Journal of Saudi Chemical Society focuses on the visible/UV light photocatalytic activities of the selected nanomaterials. Topics of these research/review articles cover diverse and exciting areas of research related to nanomaterials such as metal oxides, nanoparticles, nanocomposites, their synthesis, and photocatalysis for waste water treatment, photocatalysis for effective conversion of waste, photochemical conversions, energy generation and other chemical energy production.

Electrically Conductive Polyaniline Sensitized Defective-Tio2 For Improved Visible Light Photocatalytic And Photoelectrochemical Performance: A Synergistic Effect, M O. Ansari, Mohammad Mansoob Khan Dr, S A. Ansari, M H. Cho

Dr. Mohammad Mansoob Khan

Sulfonated polyaniline@pure-TiO2 (s-Pani@p-TiO2) and polyaniline@defective-TiO2 (s-Pani@m-TiO2) nanocomposites were prepared by the in-situ oxidative polymerization of aniline in the presence of TiO2 (p-TiO2 and m-TiO2) nanoparticles followed by sulfonation with fuming sulfuric acid. Defect-induced TiO2 (m-TiO2) nanoparticles were obtained by an electron beam (EB) treatment of commercial TiO2 (p-TiO2) nanoparticles. The resulting s-Pani@p-TiO2 and s-Pani@m-TiO2 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-TiO2 surface with intimate contact on the interface to act cooperatively with the defects introduced deliberately to achieve remarkably …

Biogenic Synthesis Of A Ag–Graphene Nanocomposite With Efficient Photocatalytic Degradation, Electrical Conductivity And Photoelectrochemical Performance, Mohammad Mansoob Khan Dr, Mohammad Ehtisham Khan, M. H. Cho Prof

Dr. Mohammad Mansoob Khan

This paper reports the environmentally benign, simple, cost efficient, one-step, surfactant free, and biogenic synthesis of silver-graphene (Ag-Graphene) nanocomposite using an electrochemically active biofilm (EAB). The EAB was used for the reduction of Ag+ to Ag0 onto the graphene sheets. The morphology, structure, composition, and optical properties and contact angle of the Ag-Graphene were obtained using a range of techniques which confirmed the anchoring/presence of silver nanoparticles (AgNPs) onto the graphene sheets. The photocatalytic activity of the Ag-Graphene was evaluated by the degradation of methylene blue and Congo red dye in aqueous solution at an ambient temperature in dark and …

Polythiophene Nanocomposites For Photodegradation Applications: Past, Present And Future, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

Polythiophene (PTh) has been the subject of considerable interest because of its good environmental stability, unique redox electrical behavior, stability in doped and neutral states, ease of synthesis, and wide range of applications in many fields. Apart from its applications in the electrical or electronic field, PTh has shown promising applications in photocatalytic degradation. The fabrication of a catalyst, metal oxides with PTh, extends the absorption range of the modified composite system, thereby enhancing the photocatalytic activity under UV or visible light irradiation. Substituted PTh, such as alkyl substitution, modifies the electronic properties of the polymer, thereby enlarging the potential …

Zno/Cdo Nanocomposites For Textile Effluent Degradation And Electrochemical Detection, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

In this report, the photocatalytic and electrochemical activity of ZnO and ZnO/CdO nanocomposites were determined. Pure ZnO and nanocomposite ZnO/CdO were prepared by a vapor to solid mechanism and were characterized by different physical and chemical techniques. The CdO-modified ZnO possessed high efficiency to degrade textile effluent. It also showed high efficiency of degradation, such as 98% for methylene blue and 93% for methyl orange. Cadmium oxide (impurity) plays an important role in achieving zinc oxide materials that exhibit UV to visible light degradation of textile effluent. Additionally, uric acid sensing performed to study the electrochemical activity revealed that ZnO/CdO …

Silver Nanoparticles And Defect-Induced Visible Light Photocatalytic And Photoelectrochemical Performance Of Ag@M-Tio2 Nanocomposite, Mohammad Mansoob Khan Dr, S. A. Ansari, M. O. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

An electrochemically active biofilm-assisted visible light active Ag@m-TiO2 photocatalyst was fabricated. The resulting nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse absorbance/reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalyst showed high photocatalytic activity and photoelectrochemical behavior due to the synergistic effect of the surface plasmon resonance (SPR) of Ag nanoparticles (AgNPs) and the induced defects in TiO2 (m-TiO2) nanoparticles. Ag@m-TiO2 nanocomposite showed much higher light harvesting ability because of the reduced band gap of m-TiO2 as well as the SPR characteristics of the AgNPs. The visible light photocatalytic experiments showed that the Ag@m-TiO2 nanocomposite possessed excellent …

Metal Oxides As Photocatalysts, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

Metal oxides are of great technological importance in environmental remediation and electronics because of their capability to generate charge carriers when stimulated with required amount of energy. The promising arrangement of electronic structure, light absorption properties, and charge transport characteristics of most of the metal oxides has made possible its application as photocatalyst. In this article definition of metal oxides as photocatalyst, structural characteristics, requirements of the photocatalyst, classification of photocatalysts and the mechanism of the photocatalytic process are discussed.

Zno/Ag/Cdo Nanocomposite For Visible Light-Induced Photocatalytic Degradation Of Industrial Textile Effluents, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

A ternary ZnO/Ag/CdO nanocomposite was synthesized using thermal decomposition method. The resulting nanocomposite was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, UV–Vis spectroscopy, and X-ray photoelectron spectroscopy. The ZnO/Ag/CdO nanocomposite exhibited enhanced photocatalytic activity under visible light irradiation for the degradation of methyl orange and methylene blue compared with binary ZnO/Ag and ZnO/CdO nanocomposites. The ZnO/Ag/CdO nanocomposite was also used for the degradation of the industrial textile effluent (real sample analysis) and degraded more than 90% in 210 min under visible light irradiation. The small size, high surface area and synergistic effect in the ZnO/Ag/CdO …

Dc Electrical Conductivity Retention And Electrical Compensation Of Polyaniline By Tio2 At Higher Loading Percentages In Polyaniline@Tio2 Nanocomposites, Mohammad Mansoob Khan Dr, M. O. Ansari, S. A. Ansari, M. H. Cho

Dr. Mohammad Mansoob Khan

Electrically conductive HCl-doped polyaniline Pani)@titanium dioxide (TiO2) nanocomposites were prepared by the in-situ oxidative polymerization of aniline in the presence of different amounts of TiO2 nanoparticles. The synthesized Pani@TiO2 nanocomposites were confirmed by transmission electron microscopy, X-ray diffraction, UV-visible spectroscopy, and thermogravimetric analysis. The stability of the Pani@TiO2 nanocomposites in terms of their electrical conductivity retention was examined under isothermal and cyclic aging conditions, and compared with that of pure Pani. The Pani@TiO2 nanocomposites showed higher thermal stability than pure Pani. The effect of competitive doping/de-doping by TiO2 was examined at different Pani to TiO2 weight ratios. TiO2 at a …

Zno/Ag/Mn2o3 Nanocomposite For Visible Lightinduced Industrial Textile Effluent Degradation, Uric Acid And Ascorbic Acid Sensing And Antimicrobial Activity, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

A facile and inexpensive route has been developed to synthesize a ternary ZnO/Ag/Mn2O3 nanocomposite having nanorod structures based on the thermal decomposition method. The as-synthesized ternary ZnO/Ag/Mn2O3 nanocomposite was characterized and used for visible light-induced photocatalytic, sensing and antimicrobial studies. The ternary ZnO/Ag/Mn2O3 nanocomposite exhibited excellent and enhanced visible light-induced photocatalytic degradation of industrial textile effluent (real sample analysis) compared to pure ZnO. Sensing studies showed that the ternary ZnO/Ag/Mn2O3 nanocomposite exhibited outstanding and improved detection of uric acid (UA) and ascorbic acid (AA). It also showed effective and efficient bactericidal activities against Staphylococcus aureus and Escherichia coli. These results …

Gold Nanoparticles-Sensitized Wide And Narrow Band Gap Tio2 For Visible Light Applications: A Comparative Study, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

Gold nanoparticles (AuNPs)-sensitized wide band gap TiO2 (Au/P-TiO2) and narrow band gap TiO2 (Au/M-TiO2) nanocomposites were prepared using an electrochemically active biofilm. The optical and structural properties of the Au/P-TiO2 and Au/M-TiO2 nanocomposites were characterized using standard techniques. The surface plasmon resonance (SPR) absorption characteristics of the AuNPs on the TiO2 surface extended the absorption edge of P-TiO2 and M-TiO2 to the visible light region. The photocatalytic activity of the Au/P-TiO2 and Au/M-TiO2 nanocomposites was evaluated by the photodegradation of methylene blue and methyl orange, and 2-chlorophenol under visible light irradiation, where Au/M-TiO2 nanocomposite exhibited enhanced photocatalytic activity compared to …

Improved Electrode Performance In Microbial Fuel Cells And The Enhanced Visible Light-Induced Photoelectrochemical Behaviour Of Ptox@M-Tio2 Nanocomposites, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

Visible light active PtOx@M-TiO2 and PtOx@P-TiO2 (x = 0, 1 and 2) nanocomposites were fabricated via a simple, green and environmentally benign process using an electrochemically active biofilm. The formation of the PtOx@M-TiO2 and PtOx@P-TiO2 nanocomposites was confirmed by X-ray diffraction, ultraviolet–visible–near infrared spectrophotometry, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS revealed the presence of Pt0, Pt2+ (PtO) and Pt4+ (PtO2) species on the surface of M-TiO2 and P-TiO2. The presence of mixed valence states of PtOx on the surface of the PtOx@M-TiO2 nanocomposite and defect states in M-TiO2 helps absorb visible light more efficiently compared to the PtOx@P-TiO2 …

Green Synthesis, Photocatalytic And Photoelectrochemical Performance Of Au-Graphene Nanocomposite, Mohammad Mansoob Khan Dr, Mohammad Ehtisham Khan, M. H. Cho

Dr. Mohammad Mansoob Khan

A simplistic and environment friendly approach using electrochemically active biofilms (EABs) was developed for the synthesis of Au-Graphene (Au-G) nanocomposite without the use of surfactants or capping agents. The as-prepared Au-G nanocomposite was characterized by X-ray diffraction, diffuse reflectance spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and transmission electron microscopy. In this study, the anchoring of gold nanoparticles (AuNPs) on graphene sheets was achieved using an EAB. The EAB assists in the bio-reduction of Au3+ to Au0, and the AuNPs prevent the aggregation of graphene sheets and keep them apart because of the decrease in attractive forces between the …

Visible Light-Induced Enhanced Photoelectrochemical And Photocatalytic Studies Of Gold Decorated Sno2 Nanostructures, Mohammad Mansoob Khan Dr, S. A. Ansari, M. E. Khan, M. O. Ansari, B. K. Min, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports a novel one-pot biogenic synthesis of Au–SnO2 nanocomposite using electrochemically active biofilm. The synthesis, morphology and structure of the as-synthesized Au–SnO2 nanocomposite were in-depth studied and confirmed by UV-vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was observed that the SnO2 surface was decorated homogeneously with Au nanoparticles. The photoelectrochemical behavior of the Au–SnO2 nanocomposite was examined by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry in the dark and under visible light irradiation. Visible light-induced photoelectrochemical studies confirmed that the Au–SnO2 nanocomposite had enhanced activities compared …

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

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.

Visible Light-Driven Photocatalytic And Photoelectrochemical Studies Of Ag-Sno2 Nanocomposites Synthesized Using An Electrochemically Active Biofilm, Mohammad Mansoob Khan Dr, S. A. Ansari, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Ag-SnO2 nanocomposites (1 mM and 3 mM) were synthesized in water at room temperature using an electrochemically active biofilm. The resulting nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy and X-ray photoelectron spectroscopy. The Ag-SnO2 nanocomposites exhibited enhanced photocatalytic activity under visible light irradiation for the degradation of methyl orange, methylene blue, 4-nitrophenol and 2-chlorophenol compared with pure SnO2 nanostructures. Photoelectrochemical measurements, such as electrochemical impedance spectroscopy, linear scan voltammetry and differential pulse voltammetry in the dark and under visible light irradiation, further supported the visible light activity of the Ag-SnO2 nanocomposites. These results …

Enhanced Thermoelectric Behaviour And Visible Light Activity Of Ag@Tio2/Polyaniline Nanocomposite Synthesized By Biogenic-Chemical Route, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports the synthesis of visible light-active Ag@TiO2/Pani nanocomposite through a facile biogenic-chemical route. Ag@TiO2/Pani nanocomposite was prepared by the in-situ oxidative polymerization of aniline in the presence of Ag@TiO2 nanocomposite, which was obtained via a biogenic route. The synthesized Ag@TiO2/Pani nanocomposite was confirmed by UV-visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The Ag@TiO2/Pani nanocomposite was doped with HCl or para-toluene sulfonic acid to render it conducting. An analysis of the thermoelectrical behavior using a cyclic aging technique showed that the electrical conductivity and thermal stability of Pani got improved after …

Defect-Induced Band Gap Narrowed Ceo2 Nanostructures For Visible Light Activities, Mohammad Mansoob Khan Dr, S. A. Ansari, D. Pradhan, D. H. Han, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This work reports an electron beam irradiation (30 kGy and 90 kGy) approach to narrow the band gap of the pristine CeO2 nanostructure (p-CeO2) to enhance their visible light activity through defect engineering. This was confirmed by diffuse reflectance spectroscopy, photoluminescence, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller, electrochemical impedance spectroscopy and linear scan voltammetry. XPS revealed changes in the surface states, composition, Ce4+ to Ce3+ ratio and other defects in the modified CeO2 nanostructures (m-CeO2). The m-CeO2 exhibits excellent photocatalytic activities by degrading 4-nitrophenol and methylene blue in the presence of visible light (λ > 400 nm) compared …

Enhanced Thermal Stability Under Dc Electrical Conductivity Retention And Visible Light Activity Of Ag/Tio2@Polyaniline Nanocomposite Film, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, K Raju, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

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/TiO2@Pani nanocomposite film via a simple biogenic-chemical route. Electrically conducting Ag/TiO2@Pani nanocomposites were prepared by incorporating Ag/TiO2 in N-methyl-2-pyrrolidone solution of polyaniline (Pani), followed by the preparation of Ag/TiO2@Pani nanocomposite film using solution casting technique. The synthesized Ag/TiO2@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/TiO2@Pani nanocomposite film showed superior activity towards the photodegradation of methylene blue under visible light compared to Pani, …

Biogenic Fabrication Of Au@Ceo2 Nanocomposite With Enhanced Visible Light Activity, Mohammad Mansoob Khan Dr, S. A. Ansari, M. O. Ansari, B. K. Min, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This study reports a biogenic approach to the synthesis of Au@CeO2 nanocomposite using electrochemically active biofilms (EABs) in water under normal pressure and 30 °C. This work presents the results of extensive morphological, structural, optical, visible light photoelectrochemical and photocatalytic studies of Au@CeO2 nanocomposite. The presence of a large number of interfaces between Au nanoparticles and CeO2 for charge transfer is believed to play a key role in enhancing the optical and visible light photoelectrochemical and photocatalytic performance of Au@CeO2 nanocomposite. The enhanced visible light degradation of methyl orange and methylene blue by Au@CeO2 nanocomposite was much higher than that …

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 …

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

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 …

Oxygen Vacancy Induced Band Gap Narrowing Of Zno Nanostructure By Electrochemically Active Biofilm, Mohammad Mansoob Khan Dr, A. A. Ansari, S. Kalathil, A. Nisar, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, x-ray photoelectron spectroscopy, electron paramagnetic …

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

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

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

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.