Nano-confined synthesis of highly ordered mesoporous carbon and its performance as electrode material for electrochemical behavior of riboflavin (vitamin B2) and dopamine

Highly ordered mesoporous carbon (MC) has been synthesized from sucrose, a non-toxic and costeffective source of carbon. X-ray diffraction, N2 adsorption–desorption isotherm and transmission electron micrograph (TEM) were used to characterize the MC. The XRD patterns show the formation of highly ordered mesoporous structures of SBA15 and mesoporous carbon. The N2 adsorptiondesorption isotherms suggest that the MC exhibits a narrow pore-size distribution with high surface area of 1559 m2/g. The potential application of MC as a novel electrode material was investigated using cyclic voltammetry for riboflavin (vitamin B2) and dopamine. MC-modified glassy carbon electrode (MC/GC) shows increase in peak current compared to GC electrode in potassium ferricyanide which clearly suggest that MC/GC possesses larger electrode area (1.8 fold) compared with bare GC electrode. The electrocatalytic behavior of MC/GC was investigated towards the oxidation of riboflavin (vitamin B2) and dopamine using cyclic voltammetry which show larger oxidation current compared to unmodified electrode and thus MC/GC may have the potential to be used as a chemically modified electrode

Recent advances in hybrid periodic mesostructured organosilica materials: opportunities from fundamental to biomedical applications

Surfactant-mediated periodic mesoporous organosilicas (PMOs) with different organic and inorganic functions in the framework structure were discovered in 1999. The silica inorganic function gives a strong mechanical stability to the framework structure and the organic functionality creates more structural flexibility. As a result, their use is optimal for a large number of applications including catalysis, microelectronics, chromatographic supports, selective adsorbents, sensors, protein folding, biomedical devices and light-harvesting devices. These new materials showed also superior stability when compared to pure mesoporous silica (PMS) framework structures. Based on the recent discoveries, since 2012, this review mostly provides a comprehensive overview of their multidisciplinary options for various applications

Catalytic nanoconfinement effect of in-situ synthesized Ni-containing mesoporous carbon scaffold (Ni-MCS) on the hydrogen storage properties of LiAlH4

We demonstrate in-situ synthesis of homogeneously dispersed Ni-containing mesoporous carbon scaffold (Ni-MCS) for improving dehydrogenation kinetics of LiAlH4 (hereafter denoted as LAH). LAH was impregnated into Ni-MCS scaffold (LAH confined-Ni-MCS) and also into pure mesoporous carbon scaffold (MCS) (LAH confined-MCS). The XRD patterns of LAH confined in Ni-MCS system indicate its amorphous nature, while 27Al MAS NMR spectroscopy confirmed the nanoconfinement of LAH in the Ni-MCS system. TPD-MS demonstrated the released of H2 at 66°C for the LAH confined-Ni-MCS system, with 84°C reduction of the onset desorption temperature (Tonset) as compared to the pure LAH. The H2 desorption from LAH confined-Ni-MCS is about 6.19 wt% H2. This strategy enables the exertion of nanoconfinement, Ni catalyst and compartmentalization effects over the growth of particle size and aggregation, which also significantly contributed to reduce the activation energy (Ea) (39.67 kJ/mol) of the system

Role of sulfur in catalytic reforming of hydrocarbons on platinum-rhenium/alumina

Cyclohexane reforming and n-heptane reforming were studied on 0.3-0.3% Pt-Re/AlO-0.95% Cl catalyst in the presence of sulfur. The combined effect of Re-S and Pt-S(Sis the irreversible form of platinum) that modified the platinum ensemble size and the electronic interactions caused the hydrogenolysis and dehydrocyclization activities to decrease. The presence of reversible sulfur (S) is explained in terms of the equilibrium between hydrogen sulfide and adsorbed S. Due to the added effect of Re-S decreasing the ensemble size, the fewer “available” free Pt crystallites on Pt-Re/AlOcompared to Pt/AlOmeans the toxicity of Swas greater for the bimetallic catalysts. The model previously proposed for sulfided Pt/AlOcan be extended to Pt-Re/AlOafter taking into consideration the additional effect of ensembling due to Re-S. Spillover of adsorbed hydrocarbon species to alumina during periods of high Slevels has been proposed for Pt-Re/AlO

Nano-Confined Synthesis of Fullerene Mesoporous Carbon (C60-FMC) with Bimodal Pores: XRD, TEM, Structural Properties, NMR, and Protein Immobilization

Nanoconfined synthesized crystalline fullerene mesoporous carbon (C60-FMC) with bimodal pore architectures of 4.95 nm and 10-15 nm pore sizes characterized by XRD, TEM, nitrogen adsorption/desorption isotherm and solid-state NMR, and the material was used for protein immobilization. The solid-state 13C NMR spectrum of C60-FMC along with XRD, BET and TEM confirms the formation of fullerene mesoporous carbon structure C60-FMC. The immobilization of albumin (from bovine serum, BSA) protein biomolecule in a buffer solution at pH 4.7 was used to determine the adsorption properties of the C60-FMC material and its structural changes investigated by FT-IR. We demonstrated that the C60-FMC with high surface area and pore volumes have excellent adsorption capacity towards BSA protein molecule. Protein adsorption experiments clearly showed that the C60-FMC with bimodal pore architectures (4.95 nm and 10-15 nm) are suitable material to be used for protein adsorption.&nbsp;</p

Low-temperature hydrogen desorption from Mg(BH4)2 catalysed by ultrafine Ni nanoparticles in a mesoporous carbon matrix

Homogenously dispersed, ultrafine Ni nanoparticles (Ni NPs) have been grown in a mesoporous carbon (MC) matrix (MC-Ni) and efficiently catalyze low-temperature hydrogen desorption from Mg(BH). The onset desorption temperature (T) of this MC-Ni-Mg(BH) system is 44\ua0°C compared to 275\ua0°C (T) for pure Mg(BH). This is the lowest value reported for hydrogen desorption from this metal hydride. The activation energy (E) of MC-Ni-Mg(BH) was determined to be 21.3\ua0kJ/mol which is less than half the value of 45.9\ua0kJ/mol for pure Mg(BH). We ascribe this reduction to the synergistic effects of nanoconfinement and the homogeneously dispersed, ultrafine Ni NPs active sites in the mesoporous carbon