Revealing the Efficient and Constant Photon Utilization of Photocatalytic Fixed Bed Reaction.

Because of the very high potential barrier, semiconductor-co-catalyst interfacial electron transfer occurring on a second time scale severely slows the photocatalytic reaction. Besides, the undesired deprivation of electrons from the co-catalyst by photogenerated oxidative intermediates in a photocatalytic slurry suspension further lowers the light-intensity-dependent photon utilization. We demonstrate here that photocatalyst immobilization can flatten the potential barrier and increase the selectivity of electrons for the target reaction. This is because the induced spatial separation of half reactions in the formed fixed bed reactors can suppress the loss of photogenerated charge carriers and increase the density of electrons in the semiconductor. The photocatalytic fixed bed reaction thus exhibits efficient and constant photon utilization.

Three-Channel Electron Transfer for Estimating Time Constants Correlated with Photocatalytic Photon Utilization.

Although the potential barrier for semiconductor-cocatalyst interfacial electron transfer can be reduced by intensifying the irradiation, the photocatalytic reaction still suffers from a low photon utilization. We here propose a trichannel electron transfer model to demonstrate that the photogenerated oxidative intermediates deprive electrons from the photocatalyst and compete with the target reaction. This model can evaluate the time constant for each electronic process involved in the target reaction and predict photocatalytic photon utilization, which is closely related to the evolution of the oxidative intermediates.

Self-Promoted H2 Formation: The Feasibility of Photoinduced CO Removal for Lossless Hydrogen Purification.

A photoinduced radical reaction operated at low temperature can be used to remove trace CO from a H2 stream by minimizing the reverse water-gas shift. However, H2 consumption resulting from nonselective oxidation by hydroxyl radicals becomes an obstacle to practical hydrogen purification. Inspired by hydrogen exchange transfer, we demonstrate here that molecular hydrogen can promote H2 formation from hydrogen radicals, which are generated from the reaction of CO and H2 with hydroxyl radicals. The slight increment in H2 along with the radical reaction encouraged us to configure a photocatalytic hydrogen purification fixed-bed reactor, which can reduce CO to ≤1 ppm in the H2 stream.

Photocatalyst: To Be Dispersed or To Be Immobilized? The Crucial Role of Electron Transport in Photocatalytic Fixed Bed Reaction.

Photocatalytic fixed bed reactors allow a straightforward separation from the process stream and simplify the installation and operation in practical application. However, it is widely believed that the restriction on mass transport and volume activation severely slows the reaction. Here, we demonstrate that photocatalytic fixed bed reactors can deliver a superior reaction rate to the slurry suspension by rationally modulating the electronic process and the most concerning issue of mass transport occurring on a decisecond time scale does not retard the reaction. Although the long-distance transport of photogenerated electrons in porous semiconductor films toward catalytic sites encounters boundary scattering, this electronic process can be far faster than semiconductor-cocatalyst interfacial electron transfer occurring on the decisecond-second time scale. Besides, the fixed bed reaction can be freely amplified without losing photon utilization. Under irradiation provided by a 320 W Hg lamp, we realize a reaction rate of 0.262 mol/h with 65.2% quantum yield for anaerobic dehydrogenation of ethanol.

Gastrolithiasis with incomplete intestinal obstruction in the perioperative period of percutaneous transluminal coronary intervention: one case report.

Gastrolithiasis is one of the uncommon clinical diseases with low incidence and its clinical manifestations are not typical. It is easy to be ignored when combined with other medical diseases. In this paper we present a case of gastrolithiasis just after percutaneous transluminal coronary intervention (PCI), the patient suffered from unexplained persistent abdominal distention and pain with gastric retention, nausea and vomiting. The patient's symptoms were similar to dyspepsia in the first 4 days, so gastrolithiasis wasn't considered, and it became worse with an incomplete intestinal obstruction on the 5th day (see the timeline for details). After a series of examinations, the patient was diagnosed as gastrolithiasis, then after endoscopic removal while taking dual antiplatelet therapy (DAPT), her condition rapidly improved and discharged after a week without any adverse events. Through following-up, the patient is very careful of diet and her digestive system symptoms seldom appear so far. So gastroscopy may be safe in the perioperative period of PCI with no history of upper gastrointestinal bleeding (UGIB). We suggest that the possibility of gastrolithiasis should be considered to avoid adverse consequences when patients have persistent abdominal distention and abdominal pain with gastric retention, which is difficult to determine the causes.

Molecular identification and mitogenome character of illegally traded tufted deer, Elaphodus cephalophus cephalophus.

The total mitogenome of the confiscated material of tufted deer, Elaphodus cephalophus cephalophus was sequenced and annotated. It is 16,351bp in length and contained 2 ribosomal RNAs, 22 transfer RNAs (tRNAs), 13 protein-coding genes (PCGs) and, 1 control region (CR). Phylogenetic analyses showed the close relationship of Elaphodus and Muntiacus, and monophyletic clades of genera Elaphodus and Muntiacus.

The complete mitogenome of Microhyla fissipes (Anura: Microhylidae) and phylogenetic analysis using GenBank data mining.

The complete mitogenome of Microhyla fissipes (16,723 bp) was obtained and analysed. It contains the set of 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and one non-coding regions. Most of the genes in M. fissipes are located on the H-strand, except for the ND6 and eight tRNA genes which are located on the L-strand. The phylogenetic tree shows that M. fissipes is a sister to the clade composed of M. okinavensis and M. mixtura and places Glyphoglossus yunnanensis as the sister lineage to a clade of Microhyla. This new mitogenome of M. fissipes will provide basic data for further molecular evolution studies in this genus.

Electronic Structures and Nanofilm Growth of 2,7-Dioctyl[1]Benzothieno[3,2-b]Benzothiophene on Black Phosphorus.

The interfacial electronic structure and morphology of nanofilm of 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on black phosphorus (BP) was investigated with photoemission spectroscopy (PES) and atomic force microscopy (AFM). The heterojunction of C8-BTBT/BP is a straddling one with a hole injection barrier of 1.41 eV and electron injection barrier of 2.43 eV from BP to C8-BTBT. There is a 0.18 eV interface dipole pointing from BP to C8-BTBT, which means a relative weak interaction of substrate BP and the C8-BTBT molecules. Volmer-Weber growth mode of C8-BTBT nanofilm on BP was confirmed and the C8-BTBT molecules adopt standing up configuration.

Exploring the scope of a novel ligand class: synthesis and catalytic examination of metal complexes with 'normal' 1,2,3-triazolylidene ligands.

Using new 'normal'-substituted 1,2,3-triazolylidene silver compounds as starting materials allowed for preparation of a series of molybdenum, ruthenium, rhodium, and palladium transition metal complexes bound to the new 1,2,3-triazolylidene ligand system. In this work, the first triazolylidene Mo compound is presented as well as the first structural investigation of a silver complex with a monodentate 1,2,3-triazolylidene. Furthermore, the triazolylidene Pd complex and the Mo complex were tested as precatalysts in Suzuki-Miyaura coupling and epoxidation catalysis, respectively.

Synthesis and comparison of transition metal complexes of abnormal and normal tetrazolylidenes: a neglected ligand species.

To date, only few examples of tetrazolylidene carbenes coordinated to transition metal complexes have been described. A direct comparison of "normal" tetrazolylidenes (1,4-substitution pattern) and "abnormal" tetrazolylidenes (also referred to as "mesoionic carbenes"; 1,3-substitution pattern) has not been performed at all. In this work, we describe coordination of both ligand types to a row of transition metals. For example, the first examples of tetrazolylidene Mo, Ag, or Ir complexes have been isolated and fully characterized. The mesoionic tetrazolylidene Ag compound 2d is shown to be a viable carbene transfer reagent. By means of NMR, IR, and Raman spectroscopy, as well as X-ray crystallography and computational results, the pronounced differences between the two ligand substitution patterns are highlighted. It is shown that simply changing the position of a methyl group from N3 to N4 in the heterocycle can cause enormous differences in ligand characteristics.