A contactless in situ EFISH method for measuring electrostatic potential profile of semiconductor/electrolyte junctions.

In photoelectrochemical cells, promising devices for directly converting solar energy into storable chemical fuels, the spatial variation of the electrostatic potential across the semiconductor-electrolyte junction is the key parameter that determines the cell performance. In principle, electric field induced second harmonic generation (EFISH) provides a contactless in situ spectroscopic tool to measure the spatial variation of electrostatic potential. However, the total second harmonic generation (SHG) signal contains the contributions of the EFISH signals of semiconductor space charge layer and the electric double layer, in addition to the SHG signal of the electrode surface.

Tailoring Interfaces for Enhanced Methanol Production from Photoelectrochemical CO Reduction.

Efficient and stable photoelectrochemical reduction of CO into highly reduced liquid fuels remains a formidable challenge, which requires an innovative semiconductor/catalyst interface to tackle. In this study, we introduce a strategy involving the fabrication of a silicon micropillar array structure coated with a superhydrophobic fluorinated carbon layer for the photoelectrochemical conversion of CO into methanol. The pillars increase the electrode surface area, improve catalyst loading and adhesion without compromising light absorption, and help confine gaseous intermediates near the catalyst surface.

Direct Vibrational Stark Shift Probe of Quasi-Fermi Level Alignment in Metal Nanoparticle Catalyst-Based Metal-Insulator-Semiconductor Junction Photoelectrodes.

Photoelectrodes consisting of metal-insulator-semiconductor (MIS) junctions are a promising candidate architecture for water splitting and for the CO reduction reaction (CORR). The photovoltage is an essential indicator of the driving force that a photoelectrode can provide for surface catalytic reactions. However, for MIS photoelectrodes that contain metal nanoparticles, direct photovoltage measurements at the metal sites under operational conditions remain challenging.

Aggregation of phosphorescent Pd(II) and Pt(II) complexes with lipophilic counter-anions in non-polar solvents.

Phosphorescent cationic tridentate C^N^N (HC^N^N = 6-(2-R,4-R-phenyl)-2,2'-bipyridine; R = R = H or F, or R = OMe, R = H) cyclometallated Pd(II) complexes with an ,-dimethyl-imidazol-allenylidene ancillary ligand (L) and their corresponding Pt(II) congeners have been synthesized and characterized, following the previously reported preparation of the complex [Pd(6-phenyl-2,2'-bipyridine)L]. For these cationic Pd(II)/Pt(II) complexes with 2,3,4-tris(dodecyloxy)benzenesulfonate (LA) counter-anions in mixed CHCl/toluene solvents, uniform square flake or fibre-like aggregates were formed. Corresponding multicolour phosphorescence with obvious metal-metal-to-ligand charge transfer (MMLCT) features gradually changed from red to NIR by manipulating the various fractions of Pd/Pt species.

Synergizing Electron and Heat Flows in Photocatalyst for Direct Conversion of Captured CO.

We report a ternary hybrid photocatalyst architecture with tailored interfaces that boost the utilization of solar energy for photochemical CO reduction by synergizing electron and heat flows in the photocatalyst. The photocatalyst comprises cobalt phthalocyanine (CoPc) molecules assembled on multiwalled carbon nanotubes (CNTs) that are decorated with nearly monodispersed cadmium sulfide quantum dots (CdS QDs). The CdS QDs absorb visible light and generate electron-hole pairs.

Highly phosphorescent organopalladium(ii) complexes with metal-metal-to-ligand charge-transfer excited states in fluid solutions.

Dinuclear pincer-type cyclometalated Pd(ii) complexes with foldable diacetylide ligands show crystallographically determined intramolecular PdPd contacts of 3.203-3.380 Å.

Palladium(ii) N-heterocyclic allenylidene complexes with extended intercationic PdPd interactions and MMLCT phosphorescence.

Extended intercationic PdPd contacts of 3.30 Å in the crystal structure and distinct MMLCT transitions absorbing at 528 nm and emitting beyond 600 nm in solutions have been revealed with cyclometalated Pd(ii) N-heterocyclic allenylidene complexes. The Pd(ii)-based MMLCT excited states are responsive to concentrations, temperatures, mechanical force and organic vapors.