Recent trend in industries toward the development of thin opto-electronic devices requires flexibility and safety for versatile applications including ubiquitous electric generators. Dye-sensitized mesoporous semiconductor electrodes can be a powerful candidate for fabrication of low-cost flexible photovoltaic devices. This review introduces low-temperature coating methods for fixing mesoporous TiO2 films on conductive plastic electrodes. Characteristics of plastic dye-sensitized solar cells assembled by this technology are also summarized, including outdoor performance of large-area full-plastic modules in comparison with commercial silicon-based solar batteries.
Detection of 2,4,6-trinitrotoluene (TNT) is an important environmental, security and health concern for the global community. TNT is a prime constituent of most of the landmines and bombs and is highly toxic and mutagenic. Various military and terrorist activities (e.g., manufacturing, waste discharge, testing and training) have resulted in extensive contamination of soil and ground water by TNT and its derivatives. Consequently, the development and application of new sensing techniques for detection and quantification of TNT has grown steadily over the years. Despite wide variety of analytical techniques, surface plasmon resonance (SPR) based immunosensors received great attention as a promising mean for TNT detection due to their advantages including high sensitivity, selectivity, good versatility and high throughput. This review explores the recent trend and advancements in immunochemical techniques for environmental monitoring and field detection of TNT. The advantages of the surface plasmon resonance as an optical signal transduction and indirect competitive immunoassay as the sensing principle are discussed with special emphasis on our investigations on TNT detection. A brief description on explosives, land-mines and the current detection techniques (bulk and trace detection) is also provided.
A short review of ionic liquids (ILs) and their applications as electrolytes for electrochemical devices, such as electric double layer capacitors, fuel cells, lithium batteries, and solar cells, are presented here. The properties of ILs, such as non-volatility, non-flammability, wide liquid temperature ranges, and wide electrochemical windows, have the potential to be improved, including improvements in durability and safety, extending the operational temperature ranges and enabling improvements in power and energy densities of the devices.
An electrocatalysis of the multi-walled carbon nanotubes (MWCNTs)/Nafion-modified edge-plane pyrolytic graphite (EPPG) electrode for the one-electron reduction-oxidation reaction of the O2/O2− (superoxide ion) redox couple in three 1-n-alkyl-3-methylimidazolium tetrafluoroborate room temperature ionic liquids (RTILs), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-n-propyl-3-methylimidazolium tetrafluoroborate (PMIBF4) and 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) has been found. We have observed that in all the RTILs both the cathodic and anodic peak currents and the peak potential separations (ΔEp) between the anodic and cathodic peak potentials at the MWCNTs/Nafion-modified electrode are increased and decreased, respectively, compared with those at the bare electrode. The values of the standard rate constant (k0) were estimated from the ΔEp values, i.e., the k0 values at the MWCNTs/Nafion-modified electrode are (8.3±0.1)×10−3, (10.4±0.1)×10−3 and (4.2±0.1)×10−3 cm s−1 in EMIBF4, PMIBF4 and BMIBF4, respectively, while the corresponding values at the bare electrode are (4.3±0.1)×10−3, (2.9±0.1)×10−3 and (2.3±0.1)×10−3 cm s−1, respectively. The observed enhancement of the O2/O2− redox reaction is discussed briefly based on the catalytic effects and physicochemical properties of carbon nanotubes.
Photochemical deposition of Pt, Ru or both on polyaniline and their electrocatalytic activity for methanol oxidation were investigated. The deposition quantity was easily controlled since it was proportional to light irradiation time. The highest activity, i.e., the largest anodic current density and the most negative onset potential, of the metal deposited polyaniline electrode were obtained by adjusting Pt/Ru deposition ratio appropriately. From a TEM image, the photodeposited metal particle size was determined to be 1∼2 nm. The bifunctional roles of the polyaniline, as a photocatalyst and an electron conductor, are also discussed.
The oxidation mechanism of hydrazine and hydroxylamine were investigated using molecular orbital (MO) calculation. Two pathways for their reactions were verified. One is initiated by hydrogen elimination from the reducing agent, followed by coordination of hydroxyl group to center nitrogen atom accompanied with electron emission. Another is initiated by coordination of hydroxyl group to hydrogen atom to form H2O, which is eliminated later, followed by electron emission. The calculated results indicated that the oxidation reactions of hydrazine preferentially proceeded via the second pathway. It was also indicated that only the first electron emission steps of the hydrazine oxidation took place on Cu surface, while the following reactions proceeded at near the solid/liquid interface. The oxidation of hydroxylamine also proceeded via the elimination reaction of H2O. After the oxidation, calculated heats of reactions suggested that OH radical, generated from N2O as a product, decomposed hydroxylamine.
Impact of corrosion inhibitors on environment has received increased attention in recent years. The new generation of environmental regulations requires the replacement of toxic chemicals with so-called “Green chemicals”. In the present study neem oil, castor oil and punga oil were used for corrosion inhibition evaluation in petroleum product (diesel) along with 2% water containing 120ppm chloride. Weight loss and polarization studies were employed to find out the corrosion inhibition efficiency (IE). Weight loss study revealed that castor oil gave higher efficiency (89%) when compared to other neem oil and punga oil. The mechanism of corrosion inhibition was investigated by using surface techniques viz., Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM).
Electropolymerization of 9,9-dialkylfluorenes (Rnfluo, n: number of carbons in the chain) with long normal alkyl chains (n=4, 5, 6, 8, and 10 compared with n=1) were investigated during sequential potential cycling. Among the Rnfluos, significant film growths were observed for the Rnfluo with n=1, 8, and 10. The R8fluo and R10fluo-based films were also found to consist of the monomer unit with higher molecular weight than the R1fluo-based film. A doping/undoping response of the new electroactive poly(R10fluo) film was compared with that of poly(R8fluo) from a fundamental viewpoint as an electrochemical capacitor material.