A theoretical model for the prediction of drop and bubble &kid-particle)

No abstract

No abstract

As one of the most promising photocatalysts, TiO 2 suffers from disadvantages of a wide band gap energy and especially the ultrafast recombination of photoinduced-charges, which limit its practical application for efficient solar water splitting. Here we show a hitherto unreported carbon/TiO 2 /carbon nanotube (CTCNT) composite featuring a TiO 2 nanotube sandwiched between two thin tubes of carbon with graphitic characteristics. The carbon layer is only about 1 nm thick covering the surface of TiO 2 nanotubes. The minimum bandgap between the edges of band tails for the CTCNTs can conjecturally be narrowed to 0.88 eV, and the measured apparent quantum efficiency of CTCNT in the ultraviolet light region is even close to 100%, indicating it can greatly enhance the utilization of sunlight and extremely suppress charge recombination. As a consequence, under illumination of one AM 1.5G sunlight, CTCNT can give a superhigh solar-driven hydrogen production rate (37.6 mmol h À1 g À1 ), which is much greater than the best yields ever reported for TiO 2 -based photocatalysts. We anticipate this work may open up new insights into the architectural design of nanostructured photocatalysts for effective capture and conversion of sunlight. Broader contextSolar-driven water-splitting into H 2 and O 2 is recognized as a promising clean, sustainable way to overcome the limited supply of fossil fuels and the greenhouse effect. This requires that photocatalysts effectively harvest sunlight and simultaneously drive the photoreaction with high quantum efficiency. The rational design of efficient catalysts for water splitting is one of the major challenges in recent years. In this work, we show a hitherto unreported carbon/TiO 2 /carbon nanotube structure (CTCNT) that features in a TiO 2 nanotube sandwiched between two thin tubes of graphitic carbon. This unique construction endows the CTCNT material with a minimum bandgap narrowing to 0.88 eV and an excellent apparent quantum efficiency of nearly 100% in the ultraviolet light region. As the result, a super-high solar-driven hydrogen production rate (37.6 mmol h À1 g À1 ) can be given by the CTCNT material, indicating it can greatly enhance the utilization of sunlight and extremely suppress the charge recombination. We anticipate this work may open up new insights to improve the photocatalytic conversion efficiency in solar-driven reactions.

No abstract

NiÀWÀB and LaÀpromoted NiÀWÀB amorphous catalysts were prepared by chemical reduction and applied within the hydrodeoxygenation (HDO) of phenol. The resulting catalysts were characterized by surface area, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that some of the electrons were transferred from B 0 to Ni 0 in NiÀWÀB amorphous catalyst. La promoted the reduction of Ni 2+ to Ni 0 and increased the WO 3 content on the catalyst surface. Adding appropriate La in NiÀWÀB amorphous catalyst improved the amorphous degree of the catalyst, but excess amounts of La covered some active sites and decreased the catalyst surface area. The HDO of phenol on these amorphous catalysts proceeded via the hydrogenationÀdehydration route, leading to no benzene in the products, which could meet the standard of clear fuel in European regulation. LaÀNiÀWÀB amorphous catalysts exhibited higher activities in the HDO of phenol than NiÀWÀB amorphous catalyst.

No abstract

No abstract