No abstract

No abstract

No abstract

A systematic study of the photocurrent activity and the nanostructure of a TiO 2 indium tin oxide ͑ITO͒ electrode prepared using reactive sputtering was carried out. The photocurrent was measured in 0.1 M NaClO 4 aqueous solution using an amperometric method under irradiation. The total conversion efficiency (eff) was estimated. Various photoelectrode TiO 2 films were synthesized by controlling deposition times, sputtering powers, total pressures, and the mole percentage of oxygen used in reactive sputtering. The physical properties of the TiO 2 film such as the crystal phase, particle size, bandgap energy, and thickness were characterized using X-ray diffraction ͑XRD͒, scanning electron microscopy ͑SEM͒, UV-visible spectroscopy, and profilometry. The results indicated that the optimal photocurrent was obtained at a thickness of approximately 1.2 m and mean particle size of approximately 50 nm. The ͑112͒-preferred orientation anatase shows higher photocurrent than ͑101͒-orientation anatase due to its regular columnar structure. The phase diagram of the prepared TiO 2 film defined by sputtering power and total pressure was also studied.

A new oxygenate additive for diesels (bio or petroleum) was manufactured using glycerol, dimethyl sulfate (DMS), and sodium hydroxide pellets as raw materials. By feeding the dimethyl sulfate into the batch reactor containing the sodium glycerate, a semibatch mode operation enhanced the effective methylation of glycerol. A conventional stirred tank reactor that can produce large quantities of oxygenate additives under a normal atmospheric pressure operation became the main feature of the methylation process. With a 3:2 molar ratio of DMS to glycerol, a 3:1 molar ratio of sodium hydroxide to glycerol, a 0.43:1 molar ratio of water to sodium hydroxide, and a temperature of 343 K at the reaction time of 24 h with the feeding time of DMS under 12 h, the conversion of glycerol (93.5%) and a combined yield of GDMEs and GTME of 71.2% were achieved for a once-through operation. A product mixture of GDME (20 wt %) and GTME (80 wt %) served as a new oxygenate additive for (bio or petroleum) diesels.