Tarik Chafik - Academia.edu (original) (raw)

Papers by Tarik Chafik

Abstract The evolution of surface species formed during the CO/H 2 reaction at 220°C on a 1wt% Rh... more Abstract The evolution of surface species formed during the CO/H 2 reaction at 220°C on a 1wt% Rh/Al 2 O 3 catalyst was studied by transient methods using both mass spectrometry and FTIR. There is a very small amount of active carbon, C α (θ C α CO =0.95). Also present on the Rh surface are a hydrogenated carbon and an inactive carbon, C β , species which do not exchange with gaseous or surface 13 CO. The amount of these two species grows with time on stream. The kinetics of isothermal hydrogenation of carbon species formed after CO/H 2 reaction depends on the Rh particle size.

Applied Catalysis A-general, Nov 1, 1993

... et al./Appl. Catal. A 101 (1993) 297-315 31549 PG Menon and GF Froment, Appl. Catal., 1 (1981... more ... et al./Appl. Catal. A 101 (1993) 297-315 31549 PG Menon and GF Froment, Appl. Catal., 1 (1981) 31.50 TM Apple, P. Gajardo and C. Dybowski, J. Catal., 68 (1981) 103.51 PT Dawson and YK Peng, Surf. Sci., 33 (1972) 565.52 ...

World

The growing interest in energy storage devices, both batteries and capacitors, could lead to the ... more The growing interest in energy storage devices, both batteries and capacitors, could lead to the improvement of electrochemical properties such as extended charge/discharge cycles, high specific capacitance, and power density. Furthermore, the use of easily available raw materials for the production of carbon electrodes has attracted interest due to the criticality of the resources related to the current technologies of high-performance capacitors. The present article reviews carbon-based materials for supercapacitors derived from affordable coal deposits or crop waste with appropriate characteristics in terms of specific surface area, electrical conductivity, and charge/discharge stability. In addition, the substitution of organic liquids electrolytes with less dangerous solutions, such as aqueous electrolytes containing high concentrations of salt, is a valuable strategy for the design of green devices that is discussed in this review. Finally, the present article reviews the elec...

Energies, Dec 20, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

2017 International Renewable and Sustainable Energy Conference (IRSEC), 2017

Molybdenum disulfide nanoparticles are known by their high performance as solid lubricants and oi... more Molybdenum disulfide nanoparticles are known by their high performance as solid lubricants and oil-additives thanks to their intrinsic structure and properties reducing wear and friction coefficient in different lubricating conditions. In this contribution, MoS2 nanospheres were successfully synthesized via a facile solvothermal route under lower temperature (190°C). Then, these nanoparticles are used as additives in PAO base oils. The dispersibility and the stability of those nano-additives was enhanced using dispersants based on alkyl-silane moieties. The synthesized nano-aditives were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transformation Infrared Spectroscopy (Ft-IR) and X-ray Analysis (EDX), while the dispersibility and the stability of the prepared suspension was studied using Dynamic Light Scattering technique and Turbiscan analysis.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021

Highlights  Flower shaped MoS 2 of about 150 nm were prepared via a hydrothermal method in a mix... more Highlights  Flower shaped MoS 2 of about 150 nm were prepared via a hydrothermal method in a mixture of ethylene glycol/water (1: 4 volume ratio).  Excellent dispersibility and long-term stability were achieved in wind turbine engine oil by surface hydrophobization of MoS 2 nanoparticles with alkyl-silane derivatives.  A high deterministic relationship was found between the stability enhancement and the tribological efficiency.  Grafting MoS 2 with longer alkyl chain (octadecyl vs octyl) lead to better tribological performance and higher lubricity power.

Chemical Engineering & Technology, 2020

2019 7th International Renewable and Sustainable Energy Conference (IRSEC), 2019

A new criterion and a potentiostatic method were carried out in order to define the electrochemic... more A new criterion and a potentiostatic method were carried out in order to define the electrochemically stable potential window (ESPW) of symmetric activated carbon electrodes cell, for capacitive ionization application in water solution with different concentration of NaCl salt. Moreover, the effect of thermal treatment of the activated carbon on the specific capacitance was investigated. The specific capacitance of activated carbon treated at 450°C present an important increase of specific capacity of 42 F g−1compared with untreated activated carbon.

International Journal of Innovation and Applied Studies, 2016

At present, although there are several studies and waste management strategies at the internation... more At present, although there are several studies and waste management strategies at the international echelon, but there is no consensual method for the characterization of waste. Also at the national level reducing the quantities of final waste with the development of recycling branches and made the valuation and reducing pollution linked to the storage and disposal of waste is a regulatory objective, political, economic and priority order for the preservation of the environment.It remains clear that a single parameter is not enough to characterize and describe such heterogeneous and hazardous waste such as those in our country: with more than 60% organic matter, a high humidity and sometimes containing hospital and / or industrial waste. The different analysis methods followed in this work is devoted to the characterization of Household Garbage and assimilated. The particularity of the sampling approach was highlighted on the landfill site based on plans of town-collect and to provi...

Leachate, the liquid percolating through solid waste, remains a major concern for managers of the... more Leachate, the liquid percolating through solid waste, remains a major concern for managers of the new controlled landfills in Morocco, especially those built under European standards i.e., with waterproof membrane and leachate collecting systems. The center of urban waste disposal of Agadir is one of these controlled landfills. After a few years of operation, the involved stakeholders are now facing the major challenge, which is dealing with the quantitative and qualitative issues of the subsequent leachate,. The aim of this study is to characterize and compare two different leachate; one from the controlled landfill of Agadir, where the analysis of the composition of heavy metals revealed a significant iron load of these effluents (36.01 mg / l), whereas, the other from the uncontrolled waste disposal of Tangier, where analyzes shows a heavy load of the leachate TSS, chlorides and iron probably due to industrial activities. Leachate samples were collected, quarterly between January...

Journal of Chemical Research, 2020

Amorphous MoS2 spheres with diameters ranging from 150 nm to 1.5 μm are successfully prepared fol... more Amorphous MoS2 spheres with diameters ranging from 150 nm to 1.5 μm are successfully prepared following a reliable one-pot hydrothermal route using a homemade autoclave and inexpensive reactants, at a low temperature (160 °C) and a short reaction time (12 h). The obtained material is comprehensively characterized by X-ray diffraction, scanning-electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, and infrared spectroscopy. The X-ray diffraction pattern reveals the amorphous structure of the prepared sample without stacking layers, whereas scanning-electron microscopy and atomic force microscopy images indicate the formation of spheres with regular shape and morphology.

Chinese Journal of Chemical Physics, 2019

Thin cuprous oxide films have been prepared by chemical vapor deposition (pulsed spray evaporatio... more Thin cuprous oxide films have been prepared by chemical vapor deposition (pulsed spray evaporation-chemical vapor deposition) method without post-treatment. The synthesis of cuprous oxide was produced by applying a water strategy effect. Then, the effect of water on the morphology, topology, structure, optical properties and surface composition of the obtained films has been comprehensively investigated. The results reveal that a pure phase of Cu 2 O was obtained. The introduction of a small quantity of water in the liquid feedstock lowers the band gap energy from 2.16 eV to 2.04 eV. This finding was mainly related to the decrease of crystallite size due to the effect of water. The topology analyses, by using atomic force microscope, also revealed that surface roughness decreases with water addition, namely more uniform covered surface. Moreover, theoretical calculations based on density functional theory method were performed to understand the adsorption and reaction behaviors of water and ethanol on the Cu 2 O thin film surface. Formation mechanism of the Cu 2 O thin film was also suggested and discussed.

Fuel, 2016

h i g h l i g h t s Illite natural clay is an interesting support for the autothermal reforming o... more h i g h l i g h t s Illite natural clay is an interesting support for the autothermal reforming of CH 4. The addition of Ce increases the surface area and the dispersion of nickel particles. The best catalytic activity and stability are obtained with the catalyst containing 15% in weight of Ce. High CH 4 and CO 2 conversions are maintain during 4 h on stream in the presence of O 2.

Journal of Nanoparticle Research

Chemical Product and Process Modeling

The design of large-scale nanomaterial production is nowadays a major research topic that require... more The design of large-scale nanomaterial production is nowadays a major research topic that requires efficient tools for appropriate decision-making and process simulation is considered among the rational approach to address such difficult issue. The present study deals with process design and economic assessment of Molybdenum Disulfide (MoS2) nanomaterials production at large-scale via solvothermal method basing on our previous bench scale results. The commercial simulator Aspen Plus was used for process modelling and assuming a plant capacity of 100 tonnes/year. The simulation results were used to perform the cost assessment and profitability analysis while taking into account two relevant cases with (Recycle Case) and without recycling of Ethylenediamine and Hydrazine (Base Case). Note that for the technological and economical assessment the effluent treatment system was not taken into account. The total capital investment was estimated to be ca.14.3 M$ for the base case and ca. 17...

C

The chemical exfoliation of graphite to produce graphene and its oxide is undoubtedly an economic... more The chemical exfoliation of graphite to produce graphene and its oxide is undoubtedly an economical method for scalable production. Carbon researchers have dedicated significant resources to developing new exfoliation methods leads to graphene oxides with high quality. However, only a few studies have been dedicated to the effect of the starting graphite material on the resulting GO. Herein, we have prepared two different GOs through chemical exfoliation of graphite materials having different textural and structural characteristics. All samples have been subjected to structural investigations and comprehensive characterizations using Raman, X-ray diffraction, scanning electron microscopy, TGA, N2 physisorption, and FTIR spectroscopy. Our results provide direct evidence of how the crystallite size of the raw graphite affects the oxidation degree, surface functionality, and sheet size of the resulting GO. Building on these significant understandings, the optimized GO achieves a highly...

2017 International Renewable and Sustainable Energy Conference (IRSEC), 2017

Today, in Morocco, there are various types of wind turbines in operation, in more than 67 station... more Today, in Morocco, there are various types of wind turbines in operation, in more than 67 stations, with a workable wind potential of 25 GW. The installation of wind farms requires a deep study of the climatic conditions of the chosen region. The most important parameter, undoubtedly, remains the wind, that influents the energy production and the life time of wind turbines. It must be optimal on where they should be built, and also requires that the wind is not blowing in all directions. On the other hand, wind turbines which do not have a pitch and yaw system, can suffer an accelerate strain in their gearboxes and consequently a minimum life time, hence the importance of an efficient lubrication that has the role of increasing the lifetime of gearboxes. In this contribution, a study of the effect of wind speed on the efficiency and reliability of wind turbines installed on Morocco parks will be presented.

La presente etude compare les proprietes d'une argile marocaine a celles d'une alumine co... more La presente etude compare les proprietes d'une argile marocaine a celles d'une alumine commerciale (Degussa P110) vis-a-vis de l'adsorption de l'o-xylene. Un interet particulier est porte a l'etude de la desorption du o-xylene dans le but de regenerer le materiau adsorbant et de recuperer le solvant. Les resultats obtenus montrent que les deux materiaux permettent d'adsorber a la temperature ambiante, 466 μmol/g sur l'argile naturelle et 1458 μmol/g sur l'alumine pour une pression partielle de xylene de 750 Pa. Les quantites adsorbees exprimees par unite de surface specifique sont tres proches sur les deux solides (13 μmol/m 2 ). L'argile naturelle se regenere plus facilement que l'alumine par traitement thermique et peut etre envisagee, a ce titre, comme un materiau d'adsorption pour la depollution des rejets gazeux contenant des composes organiques volatiles de types o-xylene.

Monoliths clay for treatment of contaminants gaseous effluents. Clays which are formed monoliths ... more Monoliths clay for treatment of contaminants gaseous effluents. Clays which are formed monoliths have interesting environmental application for simultaneous abundance, low cost, extrudability and capacity to adsorb volatile organic compounds. By the present invention the recovery of an economical and abundant in Northern Morocco so far has only been used to manufacture traditional ceramic objects by use in environmental protection technologies natural resource is intended. Moroccan studied clays can be used in the control of pollutant emissions from various types of industries, both in powder formed as monoliths with honeycomb structure. This design with recognized advantages can be achieved in these materials without further additives water and therefore without increasing the preparation process.

Abstract The evolution of surface species formed during the CO/H 2 reaction at 220°C on a 1wt% Rh... more Abstract The evolution of surface species formed during the CO/H 2 reaction at 220°C on a 1wt% Rh/Al 2 O 3 catalyst was studied by transient methods using both mass spectrometry and FTIR. There is a very small amount of active carbon, C α (θ C α CO =0.95). Also present on the Rh surface are a hydrogenated carbon and an inactive carbon, C β , species which do not exchange with gaseous or surface 13 CO. The amount of these two species grows with time on stream. The kinetics of isothermal hydrogenation of carbon species formed after CO/H 2 reaction depends on the Rh particle size.

Applied Catalysis A-general, Nov 1, 1993

... et al./Appl. Catal. A 101 (1993) 297-315 31549 PG Menon and GF Froment, Appl. Catal., 1 (1981... more ... et al./Appl. Catal. A 101 (1993) 297-315 31549 PG Menon and GF Froment, Appl. Catal., 1 (1981) 31.50 TM Apple, P. Gajardo and C. Dybowski, J. Catal., 68 (1981) 103.51 PT Dawson and YK Peng, Surf. Sci., 33 (1972) 565.52 ...

World

The growing interest in energy storage devices, both batteries and capacitors, could lead to the ... more The growing interest in energy storage devices, both batteries and capacitors, could lead to the improvement of electrochemical properties such as extended charge/discharge cycles, high specific capacitance, and power density. Furthermore, the use of easily available raw materials for the production of carbon electrodes has attracted interest due to the criticality of the resources related to the current technologies of high-performance capacitors. The present article reviews carbon-based materials for supercapacitors derived from affordable coal deposits or crop waste with appropriate characteristics in terms of specific surface area, electrical conductivity, and charge/discharge stability. In addition, the substitution of organic liquids electrolytes with less dangerous solutions, such as aqueous electrolytes containing high concentrations of salt, is a valuable strategy for the design of green devices that is discussed in this review. Finally, the present article reviews the elec...

Energies, Dec 20, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

2017 International Renewable and Sustainable Energy Conference (IRSEC), 2017

Molybdenum disulfide nanoparticles are known by their high performance as solid lubricants and oi... more Molybdenum disulfide nanoparticles are known by their high performance as solid lubricants and oil-additives thanks to their intrinsic structure and properties reducing wear and friction coefficient in different lubricating conditions. In this contribution, MoS2 nanospheres were successfully synthesized via a facile solvothermal route under lower temperature (190°C). Then, these nanoparticles are used as additives in PAO base oils. The dispersibility and the stability of those nano-additives was enhanced using dispersants based on alkyl-silane moieties. The synthesized nano-aditives were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transformation Infrared Spectroscopy (Ft-IR) and X-ray Analysis (EDX), while the dispersibility and the stability of the prepared suspension was studied using Dynamic Light Scattering technique and Turbiscan analysis.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021

Highlights  Flower shaped MoS 2 of about 150 nm were prepared via a hydrothermal method in a mix... more Highlights  Flower shaped MoS 2 of about 150 nm were prepared via a hydrothermal method in a mixture of ethylene glycol/water (1: 4 volume ratio).  Excellent dispersibility and long-term stability were achieved in wind turbine engine oil by surface hydrophobization of MoS 2 nanoparticles with alkyl-silane derivatives.  A high deterministic relationship was found between the stability enhancement and the tribological efficiency.  Grafting MoS 2 with longer alkyl chain (octadecyl vs octyl) lead to better tribological performance and higher lubricity power.

Chemical Engineering & Technology, 2020

2019 7th International Renewable and Sustainable Energy Conference (IRSEC), 2019

A new criterion and a potentiostatic method were carried out in order to define the electrochemic... more A new criterion and a potentiostatic method were carried out in order to define the electrochemically stable potential window (ESPW) of symmetric activated carbon electrodes cell, for capacitive ionization application in water solution with different concentration of NaCl salt. Moreover, the effect of thermal treatment of the activated carbon on the specific capacitance was investigated. The specific capacitance of activated carbon treated at 450°C present an important increase of specific capacity of 42 F g−1compared with untreated activated carbon.

International Journal of Innovation and Applied Studies, 2016

At present, although there are several studies and waste management strategies at the internation... more At present, although there are several studies and waste management strategies at the international echelon, but there is no consensual method for the characterization of waste. Also at the national level reducing the quantities of final waste with the development of recycling branches and made the valuation and reducing pollution linked to the storage and disposal of waste is a regulatory objective, political, economic and priority order for the preservation of the environment.It remains clear that a single parameter is not enough to characterize and describe such heterogeneous and hazardous waste such as those in our country: with more than 60% organic matter, a high humidity and sometimes containing hospital and / or industrial waste. The different analysis methods followed in this work is devoted to the characterization of Household Garbage and assimilated. The particularity of the sampling approach was highlighted on the landfill site based on plans of town-collect and to provi...

Leachate, the liquid percolating through solid waste, remains a major concern for managers of the... more Leachate, the liquid percolating through solid waste, remains a major concern for managers of the new controlled landfills in Morocco, especially those built under European standards i.e., with waterproof membrane and leachate collecting systems. The center of urban waste disposal of Agadir is one of these controlled landfills. After a few years of operation, the involved stakeholders are now facing the major challenge, which is dealing with the quantitative and qualitative issues of the subsequent leachate,. The aim of this study is to characterize and compare two different leachate; one from the controlled landfill of Agadir, where the analysis of the composition of heavy metals revealed a significant iron load of these effluents (36.01 mg / l), whereas, the other from the uncontrolled waste disposal of Tangier, where analyzes shows a heavy load of the leachate TSS, chlorides and iron probably due to industrial activities. Leachate samples were collected, quarterly between January...

Journal of Chemical Research, 2020

Amorphous MoS2 spheres with diameters ranging from 150 nm to 1.5 μm are successfully prepared fol... more Amorphous MoS2 spheres with diameters ranging from 150 nm to 1.5 μm are successfully prepared following a reliable one-pot hydrothermal route using a homemade autoclave and inexpensive reactants, at a low temperature (160 °C) and a short reaction time (12 h). The obtained material is comprehensively characterized by X-ray diffraction, scanning-electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, and infrared spectroscopy. The X-ray diffraction pattern reveals the amorphous structure of the prepared sample without stacking layers, whereas scanning-electron microscopy and atomic force microscopy images indicate the formation of spheres with regular shape and morphology.

Chinese Journal of Chemical Physics, 2019

Thin cuprous oxide films have been prepared by chemical vapor deposition (pulsed spray evaporatio... more Thin cuprous oxide films have been prepared by chemical vapor deposition (pulsed spray evaporation-chemical vapor deposition) method without post-treatment. The synthesis of cuprous oxide was produced by applying a water strategy effect. Then, the effect of water on the morphology, topology, structure, optical properties and surface composition of the obtained films has been comprehensively investigated. The results reveal that a pure phase of Cu 2 O was obtained. The introduction of a small quantity of water in the liquid feedstock lowers the band gap energy from 2.16 eV to 2.04 eV. This finding was mainly related to the decrease of crystallite size due to the effect of water. The topology analyses, by using atomic force microscope, also revealed that surface roughness decreases with water addition, namely more uniform covered surface. Moreover, theoretical calculations based on density functional theory method were performed to understand the adsorption and reaction behaviors of water and ethanol on the Cu 2 O thin film surface. Formation mechanism of the Cu 2 O thin film was also suggested and discussed.

Fuel, 2016

h i g h l i g h t s Illite natural clay is an interesting support for the autothermal reforming o... more h i g h l i g h t s Illite natural clay is an interesting support for the autothermal reforming of CH 4. The addition of Ce increases the surface area and the dispersion of nickel particles. The best catalytic activity and stability are obtained with the catalyst containing 15% in weight of Ce. High CH 4 and CO 2 conversions are maintain during 4 h on stream in the presence of O 2.

Journal of Nanoparticle Research

Chemical Product and Process Modeling

The design of large-scale nanomaterial production is nowadays a major research topic that require... more The design of large-scale nanomaterial production is nowadays a major research topic that requires efficient tools for appropriate decision-making and process simulation is considered among the rational approach to address such difficult issue. The present study deals with process design and economic assessment of Molybdenum Disulfide (MoS2) nanomaterials production at large-scale via solvothermal method basing on our previous bench scale results. The commercial simulator Aspen Plus was used for process modelling and assuming a plant capacity of 100 tonnes/year. The simulation results were used to perform the cost assessment and profitability analysis while taking into account two relevant cases with (Recycle Case) and without recycling of Ethylenediamine and Hydrazine (Base Case). Note that for the technological and economical assessment the effluent treatment system was not taken into account. The total capital investment was estimated to be ca.14.3 M$ for the base case and ca. 17...

C

The chemical exfoliation of graphite to produce graphene and its oxide is undoubtedly an economic... more The chemical exfoliation of graphite to produce graphene and its oxide is undoubtedly an economical method for scalable production. Carbon researchers have dedicated significant resources to developing new exfoliation methods leads to graphene oxides with high quality. However, only a few studies have been dedicated to the effect of the starting graphite material on the resulting GO. Herein, we have prepared two different GOs through chemical exfoliation of graphite materials having different textural and structural characteristics. All samples have been subjected to structural investigations and comprehensive characterizations using Raman, X-ray diffraction, scanning electron microscopy, TGA, N2 physisorption, and FTIR spectroscopy. Our results provide direct evidence of how the crystallite size of the raw graphite affects the oxidation degree, surface functionality, and sheet size of the resulting GO. Building on these significant understandings, the optimized GO achieves a highly...

2017 International Renewable and Sustainable Energy Conference (IRSEC), 2017

Today, in Morocco, there are various types of wind turbines in operation, in more than 67 station... more Today, in Morocco, there are various types of wind turbines in operation, in more than 67 stations, with a workable wind potential of 25 GW. The installation of wind farms requires a deep study of the climatic conditions of the chosen region. The most important parameter, undoubtedly, remains the wind, that influents the energy production and the life time of wind turbines. It must be optimal on where they should be built, and also requires that the wind is not blowing in all directions. On the other hand, wind turbines which do not have a pitch and yaw system, can suffer an accelerate strain in their gearboxes and consequently a minimum life time, hence the importance of an efficient lubrication that has the role of increasing the lifetime of gearboxes. In this contribution, a study of the effect of wind speed on the efficiency and reliability of wind turbines installed on Morocco parks will be presented.

La presente etude compare les proprietes d'une argile marocaine a celles d'une alumine co... more La presente etude compare les proprietes d'une argile marocaine a celles d'une alumine commerciale (Degussa P110) vis-a-vis de l'adsorption de l'o-xylene. Un interet particulier est porte a l'etude de la desorption du o-xylene dans le but de regenerer le materiau adsorbant et de recuperer le solvant. Les resultats obtenus montrent que les deux materiaux permettent d'adsorber a la temperature ambiante, 466 μmol/g sur l'argile naturelle et 1458 μmol/g sur l'alumine pour une pression partielle de xylene de 750 Pa. Les quantites adsorbees exprimees par unite de surface specifique sont tres proches sur les deux solides (13 μmol/m 2 ). L'argile naturelle se regenere plus facilement que l'alumine par traitement thermique et peut etre envisagee, a ce titre, comme un materiau d'adsorption pour la depollution des rejets gazeux contenant des composes organiques volatiles de types o-xylene.

Monoliths clay for treatment of contaminants gaseous effluents. Clays which are formed monoliths ... more Monoliths clay for treatment of contaminants gaseous effluents. Clays which are formed monoliths have interesting environmental application for simultaneous abundance, low cost, extrudability and capacity to adsorb volatile organic compounds. By the present invention the recovery of an economical and abundant in Northern Morocco so far has only been used to manufacture traditional ceramic objects by use in environmental protection technologies natural resource is intended. Moroccan studied clays can be used in the control of pollutant emissions from various types of industries, both in powder formed as monoliths with honeycomb structure. This design with recognized advantages can be achieved in these materials without further additives water and therefore without increasing the preparation process.