A Facile and Green Method for the Synthesis of SFE Borosilicate Zeolite and Its Heteroatom-Substituted Analogues with Promising Catalytic Performances.

Synthesis of SFE-type borosilcate zeolite was successfully carried out using a commercially available low-cost organic structure directing agent (OSDA) with ultra-low OSDA and water contents within a short crystallization time. Heteroatom (Al, Ti, V, or Fe)-substituted SFE-type zeolite analogues were also directly synthesized for the first time. The obtained Al containing zeolites exhibited promising catalytic performances in the disproportionation of isopropylnaphthalene.

Photo-induced H2 production from a CH3OH-H2O solution at insulator surface.

In a conventional photocatalytic or photochemical process, either a photocatalyst or a molecule is excited by irradiation light that has energy greater than the forbidden band (i.e., the band gap) of the semiconductor or the transition energy of an excited state of the molecule, respectively, for a reaction to occur. However, in this work, we found that a considerable amount of H2 can be generated from a CH3OH-H2O solution at a quartz surface using light with energy far outside the electronic absorbance range of the CH3OH-H2O solution; this process should not occur in principle via either conventional photocatalysis or a photochemical process. The H2 production was further confirmed using 266 nm and 355 nm lasers as light sources. Our work demonstrates that photo-induced H2 production can occur on insulator surfaces (e.g., quartz), which were commonly believed to be inert, and will shed light on the surface nature of insulators.

Construction of unique six-coordinated titanium species with an organic amine ligand in titanosilicate and their unprecedented high efficiency for alkene epoxidation.

A novel organic-inorganic layered titanosilicate consisting of Ti-containing MWW-type nanosheets and piperidine ligands was constructed. It exhibited an unprecedented high catalytic activity and recyclability in alkene epoxidation.

Note: deep ultraviolet Raman spectrograph with the laser excitation line down to 177.3 nm and its application.

Deep UV Raman spectrograph with the laser excitation line down to 177.3 nm was developed in this laboratory. An ellipsoidal mirror and a dispersed-subtractive triple monochromator were used to collect and disperse Raman light, respectively. The triple monochromator was arranged in a triangular configuration with only six mirrors used. 177.3 nm laser excited Raman spectrum with cut-off wavenumber down to 200 cm(-1) and spectral resolution of 8.0 cm(-1) can be obtained under the condition of high purity N2 purging. With the C-C σ bond in Teflon selectively excited by the 177.3 nm laser, resonance Raman spectrum of Teflon with good quality was recorded on the home-built instrument and the σ-σ(*) transition of C-C bond was studied. The result demonstrates that deep UV Raman spectrograph is powerful for studying the systems with electronic transition located in the deep UV region.

Effects of Zn2+ and Pb2+ dopants on the activity of Ga2O3-based photocatalysts for water splitting.

Zn-doped and Pb-doped ß-Ga2O3-based photocatalysts were prepared by an impregnation method. The photocatalyst based on the Zn-doped ß-Ga2O3 shows a greatly enhanced activity in water splitting while the Pb-doped ß-Ga2O3 one shows a dramatic decrease in activity. The effects of Zn(2+) and Pb(2+) dopants on the activity of Ga2O3-based photocatalysts for water splitting were investigated by HRTEM, XPS and time-resolved IR spectroscopy. A ZnGa2O4-ß-Ga2O3 heterojunction is formed in the surface region of the Zn-doped ß-Ga2O3 and a slower decay of photogenerated electrons is observed. The ZnGa2O4-ß-Ga2O3 heterojunction exhibits type-II band alignment and facilitates charge separation, thus leading to an enhanced photocatalytic activity for water splitting. Unlike Zn(2+) ions, Pb(2+) ions are coordinated by oxygen atoms to form polyhedra as dopants, resulting in distorted surface structure and fast decay of photogenerated electrons of ß-Ga2O3. These results suggest that the Pb dopants act as charge recombination centers expediting the recombination of photogenerated electrons and holes, thus decreasing the photocatalytic activity.