Anatase TiO2 nanocrystals (aTiO2) of a uniform size have been synthesized and were subject to successive hydrogenation under H2 gas flow at elevated temperatures (500–700 °C). We found that the concentration Ti3+ defects, such as interstitials oxygen vacancies, their distribution between surface bulk varied significantly, depending on temperature time. Such changes in defects be critical enhancing photoactivity hydrogenated (H-aTiO2) by an order magnitude. In our case, H-aTiO2 600 °C for...

Composite materials based on g-C3N4 and TiO2 nanotubes have been synthesized as environmentally friendly photocatalysts with heterojunctions suitable for enhanced photocatalytic hydrogen production. Composites were prepared various ratios (x = 0–1) of after chemical modification exfoliation bulk g-C3N4. Contact formation between generally photoactivity, which caused the x-dependent changes in evolution rates g-C3N4/TiO2 compounds to vary following a volcano-shaped curve maximum rate at x ∼...

Abstract Copper‐catalyzed aerobic coupling of thiols and alcohols affords sulfinates thiosulfonates. These products are assumed to form via sulfinyl radicals which not commonly found in oxidative reactions thiols. A reaction mechanism involving is proposed, mass electron paramagnetic resonance (EPR) experimental results provided. magnified image

Abstract The anisotropic properties of 2D orthorhombic SnS (tin monosulfide, p‐type) layers can be utilized in energy‐efficient optoelectronics by growing with a preferred orientation. To meet such need, strategy for the control structural parameters as orientation and thickness is highly desired. This report demonstrates simple procedure large‐area thin film composed nanoscale platelets controlled relative to surface via single‐step process involving situ sulfur depletion phase transition...

Our study of a (WO3)3/TiO2(110) model mixed oxide catalyst shows that this system is an extremely efficient for dehydration alcohols, effectively lowering the energy barrier as much possible endothermic reaction without yielding significant concentration other side products.

Product yields and selectivities, based on ultrahigh vacuum temperature-programmed desorption, are compared for 10 C2 to C8 aliphatic alcohols dosed at 100 K highly ordered TiO2(110) with a 3.5% concentration of surface oxygen vacancies. Dehydration form an alkene water typically dominates, while two other channels, dehydrogenation aldehyde re-formation alcohol, make detectable contributions primary alcohols. Depending the there distinct dehydration pathways:  one operative low temperature...

Dosed on rutile TiO2(110) at 100 K, the thermal chemistry of 2-propanol in three formsC3H7OH, C3D7OD, and C3H7ODwas characterized using temperature-programmed desorption. Only 2-propanol, propene, water desorb with no evidence for acetone. The propene forms desorbs by two paths, a heretofore unreported low-temperature path extending from 300 to 450 K and, concurring prior work, high-temperature peaking between 570 580 K. Both paths exhibit isotope effects. is interpreted terms decomposition...

The reactions of C1−C4 aliphatic alcohols over (WO3)3 clusters were studied experimentally and theoretically using temperature-programmed desorption, infrared reflection−absorption spectroscopy, density functional theory. results reveal that all readily react with by heterolytic cleavage the RO−H bond to give alkoxy (RO−) bound W(VI) centers a proton (H+) attached terminal oxygen atom tungstyl group (W═O). Two protons adsorbed onto cluster doubly bonded from water molecule desorbs at 200−300...

Ordered ultrathin tungsten oxide films were prepared on a Pt(111) substrate at 700 K via direct sublimation of monodispersed cyclic (WO3)3 trimers. The surface composition, structure, and morphology determined using combination atomically resolved imaging, ensemble-averaged surface-sensitive spectroscopies, DFT. We find that half the atoms in first layer get partially reduced to (5+) oxidation state. opening ring leads formation with zigzag chain structure c(4 × 2) periodicity. In second...

Shape-controlled anatase TiO2 nanocrystals with large {001} facets are synthesized by a hydrothermal method using HF as shape-controlling agent. The photoactivity of the is evaluated from photodegradation rate methylene blue in aqueous solution under UV irradiation. Here, we observe higher photoactivities for ratio close to 60%, which shape effect photoactivity. In addition, that further enhanced when treated dilute NaOH (HF) solution. Our SEM, XPS, and EPR analyses reveal etching can induce...

Photocathodes made from the earth-abundant, ecofriendly mineral tin monosulfide (SnS) can be promising candidates for p/n-type photoelectrochemical cells because they meet strict requirements of energy band edges each individual photoelectrode. Herein we fabricated SnS-based cell that exhibited a prolonged photocurrent 3 h at −0.3 V vs reversible hydrogen electrode (RHE) in 0.1 M HCl electrolyte. An enhancement cathodic 2 to 6 mA cm–2 is observed through rapid thermal treatment....

High-resolution core-level photoemission using synchrotron radiation is applied to the ultrathin SiON films on Si(100) nitrided by ${\mathrm{N}}_{2}$ plasma, which gives a systematic view of various transient or stable N chemical states. $\mathrm{N}\phantom{\rule{0.3em}{0ex}}1s$ spectra disclose at least two characteristic nitrogen bonding states in addition well-established and thermally $\mathrm{N}{\mathrm{Si}}_{3}$ species. While species are located near interface, extra high-binding...

Abstract Multi N ‐heterocyclic carbene(NHC)‐modified iridium catalysts were employed in the β‐alkylation of alcohols; dimerization primary alcohols (Guerbet reaction), cross‐coupling secondary and alcohols, intramolecular cyclization alcohols. Mechanistic studies Guerbet reaction, including kinetic experiments, mass analysis, density functional theory (DFT) calculation, to explain fast reaction promoted by bimetallic catalysts, dramatic reactivity increase monometallic at late stage...

The formation of heterojunctions for efficient charge separation has been practiced the preparation semiconductor-based photocatalysts applications such as hydrogen production and environmental remediation. In this study, we synthesized a composite structure with heterojunction between SnS2 TiO2 through microwave-assisted hydrothermal process, in which nanoparticles grew on nanocrystalline nanosheets preferentially at exposed {101} facets. Appropriate exposure {001} facets nanosheet...

High-resolution photoemission spectroscopy using synchrotron radiation was employed to understand the bonding state of N incorporated into a reduced TiO2(110)-1×1 surface. N-doping TiO2(110) accomplished both by dosing NH3 at elevated temperatures (800 K) and NHx+ ion implantation method onto room temperature. Our results indicate that N-doped obtained after final annealing 900 K contains species subsurface region TiO2substitutionally replacing lattice O2–. Interestingly, we find some are...

Mono‐ and bimetallic iridium complexes involving novel triscarbene ligands were synthesized applied to the dehydrogenation of biomass‐derived glycerol. This resulted in affording hydrogen lactate with excellent turnover number (TON; 3,240,000) frequency (TOF; 162,000 h – 1 ). The ligand a single frame allowed formation complexes. induced cooperative effect two ions rendered TONs TOFs production lactate.

The dehydration of 1-propanol on nanoporous WO3 films prepared via ballistic deposition at ∼20 K has been investigated using temperature-programmed desorption, infrared reflection absorption spectroscopy, and density functional theory. as-deposited are extremely efficient in to propene. This activity is correlated with the presence dioxo O═W═O groups, whereas monooxo W═O species shown be inactive. Annealing induces densification that results loss catalytic due annihilation species.