Md. Khorshed Alam

• PhD ( Engineering)
• Head of Faculty at University of Barishal

Predicting electronically excited states across electron-donor/electron acceptor interfaces is essential for understanding charge photogeneration process in organic solar cells. However, organic solar cells are large and disordered systems, and their...

In this study, the density functional theory (DFT) and Monte Carlo (MC) simulations were conducted to determine the equilibrium conformation of Pt2Ru3 nanoparticles with diameters 1.0–3.5 nm at finite temperature. DFT calculations were carried out to estimate the binding energy using slab configurations and energy could be correlated with some stru...

his paper presents a periodic density functional theory study on the adsorption of H, CO, and OH on Pt2Ru3 alloy surfaces containing different conformations of Pt and Ru atoms. The results show that for separate adsorption, H is preferentially adsorbed at Pt sites, whereas CO and OH are preferentially adsorbed at Ru sites. The adsorption strengths...

For improving the tribological performance of hard disk drives, nanometer-thick perfluoropolyether (PFPE) lubricant films are generally treated with ultraviolet (UV) irradiation to bond them to the carbon overcoats of the disks. By modeling UV irradiation as an electron emission and attachment process, we investigate the UV bonding of nonfunctional...

Ceria has attracted intensive interest in the past decade because of its vital role in emerging technologies for exhaust gas purification in automobiles. In this study, we have investigated the process of conversion of CO to CO2 via the creation of an oxygen vacancy on the ceria surface. The study was conducted using a new ultra accelerated quantum...

We investigated CO coverage ( θ CO ) on Pt 2 Ru 3 nanoparticle with various morphologies in H 2 /CO mixture gas atmosphere at 333 K by grand canonical ensemble Monte Carlo (GCMC) combined with quantitative structure–property relationship. In nanoparticles enclosed by (111) facets, θ CO was significantly reduced when the surface and the subsurface w...

Graphene Oxide (GO) and Reduced Graphene Oxide (RGO) have become the main focal point of research interest for their extraordinary physic-chemical properties of materials performance and potential fields of applications in various sectors, especially in electronic, optoelectronic device and circuit etc. The purpose of this study is to investigate t...

Infrared (IR) photodissociation spectra of adenine-thymine (AT +) hetero-dimer cluster has been recorded in the region of 2900-3700 cm-1 in order to investigate the most stable conformer of adenine-thymine hetero-dimer. A new conformer (conformer I) was found which is more stable by 285, 221 and 312 cm-1 than the Watson-Crick conformer (conformer I...

Reducing the head-media spacing is of crucial importance in enabling future high-density magnetic recording. In this work,we have studied the effect of nitrogen incorporation and ultraviolet (UV) irradiation on the interaction between the perfluoropolyether (PFPE) to the carbon surface using quantum chemical method. This paper explores that the UV...

The energy from sunlight reaching the earth is a vast potential that can be exploited and used for generating electricity. Among several available technologies, solar Photovoltaic (PV) is the most promising. PV technology converts sunlight into direct current (DC) electricity. When light falls on the active surface of the solar cell, electrons beco...

In this work, molecular dynamics (MD) study of triglyme (G3) solution containing lithium bis (trifluoro methyl sulfonyl) amide (Li[TFSA]) were investigated using classical atomistic force fields. G3 is a typical solvent used in non-aqueous Li-air battery. It shows here coordination of Li+ with G3 and [TFSA]-does not significantly change with increa...

The electronic structure at organic-organic interfaces is of great importance in the performance of various organic electronic devices. In organic photovoltaic (OPV) devices charge-transfer (CT) states at the interface between electron donor (D) and electron acceptor (A) materials play a major role in both exciton-dissociation and charge-recombinat...

Terahertz (THz) absorption spectra of poly 3-hydroxyalkanoates (PHB) for different conformations were investigated using molecular dynamics (MD) method. Temperature-dependent THz absorption spectra of PHB were measured over a temperature range of 10 K to 200 K. Peaks around (2.4-2.6THz) and (3.1-3.2THz) were observed due to vibrational transition o...

Terahertz (THz) absorption spectra of poly 3-hydroxyalkanoates (PHB) for different conformations were investigated using molecular dynamics (MD) method. Temperature-dependent THz absorption spectra of PHB were measured over a temperature range of 10 K to 200 K. Peaks around (2.4-2.6THz) and (3.1-3.2THz) were observed due to vibrational transition o...

This study deals with the benchmark analysis of a cross section library generated from Japanese evaluated nuclear data library (JENDL)-3.3 for the winfrith improved multi- group scheme (WIMS) D-5B code system by calculating the theoretical results of the integral parameters for TRX and BAPL benchmark lattices of thermal reactor. The nuclear data pr...

We have investigated the equilibrium conformation of Pt2Ru3 nanoparticles in the presence of H2 and CO mixture gas using density functional theory (DFT) and Monte Carlo (MC) simulation. A multiple linear regression equation was prepared using DFT results to calculate adsorption energy from the structural descriptors. Using the regression equation,...

Ti doping in CeO 2 can be used to modify its reactivity with respect to the oxygen vacancy formation and the redox properties. In the present study, we have investigated the effect of Ti doping on CeO 2 surface and its reduction properties using ultra accelerated quantum chemical molecular dynamics (UA-QCMD) method. A substitution of Ce atom by Ti...

Ti doping in CeO 2 can be used to modify its reactivity with respect to the oxygen vacancy formation and the redox properties. In the present study, we have investigated the effect of Ti doping on CeO 2 surface and its reduction properties using ultra accelerated quantum chemical molecular dynamics (UA-QCMD) method. A substitution of Ce atom by Ti...

This study deals with the benchmark analysis of a cross section library generated from Japanese evaluated nuclear data library (JENDL)-3.3 for the winfrith improved multi-group scheme (WIMS) D-5B code system by calculating the theoretical results of the integral parameters for TRX and BAPL benchmark lattices of thermal reactor. The nuclear data pro...

We present classical molecular dynamics (MD) and first principles molecular dynamics (FPMD) studies to investigate the transport mechanisms of hydroxide ions through poly(arylene ether sulfone ketone)s containing quaternized ammonio-substituted fluorenyl groups (QPE) as anion exchange polymers used in applications such as alkaline fuel cells. The e...

Attended this conference with special invitation and travel award by ICTP

Third-generation solar cells are understood to be the pathway to overcoming the issues and drawbacks of the existing solar cell technologies. Since the introduction of graphene in solar cells, it has been providing attractive properties for the next generation of solar cells. Currently, there are more theoretical predictions rather than practical r...

It has long been considered that Pt is the most effective electrocatalysts for PEMFCs. If pure hydrogen is used as the fuel, Pt is a good anode material, but Pt anodes are deactivated by little amount of CO in the H2 fuel [1]. It is well established that the catalytic properties of metal can be markedly changed by alloying with a second metal in po...

In this work, we present results of periodic density functional theory study of the adsorption of carbon monoxide (CO) and hydroxyl (OH) on Pt2Ru3 alloy surface for different conformation of Pt and Ru. These results were compared with CO and OH adsorption on pure Pt and Ru surfaces. We find that the mixing of Pt by Ru leads to stronger bond of CO a...

It is well known that Pt-Ru alloy exhibits a promising catalytic activity for fuel cells. In this work we present density functional theory (DFT) study of the randomly mixed Pt-Ru alloys and discussed its stability based on the relative position of Pt and Ru atoms. The structures are modelled as five layer slabs because the ratio of surface atoms c...

The lithium-O2 systems capture worldwide attention as a possible battery for electric vehicle propulsion. However, there are numerous scientific and technical challenges that must be overcome if this alluring promise is to turn into reality. In this study, using first principles molecular dynamics (FPMD), we first time report the dynamical behavior...

In the recent years, interest has grown in the development of anion exchange membranes (AEMs) for alkaline fuel cells, which have advantage over proton exchange membranes (PEM) fuel cells including cost and performance. In this work, we present molecular dynamics (MD) and first principles molecular dynamics (FPMD) studies to investigate transport m...

Santa Clara, California, USA, June 18-20, 2012.

Nagoya, Japan, May 10-12, 2012

Ceria plays an important role in catalysis, due to its ability to store and release oxygen depending on the condition present in the catalyst environment. To analyze the role of ceria in catalytic reactions it is necessary to know the details of the interaction of ceria surface with environmentally sensitive molecules. This study was conducted usin...

In this article modeling of dissociative adsorption of hydrogen on Pd (1 1 1) surface by ultra-accelerated quantum chemical molecular dynamics (UA-QCMD) was reported for the better understanding of the role of hydrogen vacancy for the dissociative adsorption of hydrogen. Here we have demonstrated and examined the isolated steps of hydrogen dissocia...

In catalytic reaction doping of metal oxides can be used to modify their reactivity. Ti doping may change the reduction properties of ceria. Here we study the Ti doping effects on ceria surface and its redox behavior using ultra accelerated quantum chemical molecular dynamics (UA-QCMD) method.

Ultra accelerated quantum chemical molecular dynamics method (UA-QCMD) was used to study the dynamics of the hydrogen spillover process on Pt/CeO2 catalyst surface for the first time. The direct observation of dissociative adsorption of hydrogen on Pt/CeO2 catalyst surface as well as the diffusion of dissociative hydrogen from the Pt/CeO2 catalyst...

Ceria plays an important role in catalysis, due to its ability to store and release oxygen depending on the condition present in the catalyst environment. To analyze the role of ceria in catalytic reactions, it is necessary to know the details of the interaction of ceria surface with environmentally sensitive molecules. This study was conducted usi...

The hydrogen spillover mechanism has earned intensive interest in the past decades because it plays a vital role in emerging technologies for the reduction of NOx in automobile exhausts. Hydrogen spillover arises in hydrogen-catalyzed reactions on a supported metal catalyst. In the present study, we applied quantum chemical molecular dynamics (QCMD...