Abstract: The present disclosure provides a method for facet-selective passivation on each crystal facet of colloidal nanocrystals via solution-phase ligand exchange process, thereby providing highly-passivated and colloidally-stable nanocrystal inks. This ligand exchange strategy separately addresses polar and non-polar facets precluding from deleterious nanocrystal aggregation in the colloid. The method involves the introduction of alkali metal organic complexes during metal halide conventional solution exchanges, and one specific example is Na+·Ac?. Alkali metal ions stabilize and passivate non polar facets whereas polar facets are passivated through metal halides. This strategy leads to a significant decrease in nanocrystal aggregation during and after ligand exchange, and to improved photophysical properties stemming from this. The resulting nanocrystal solid films exhibit improved stability, retain their absorption features, and have a minimized Stokes shift.

Abstract: The invention relates to a composite multilayer carbon dioxide (CO2) reduction catalyst, comprising a catalyst layer comprising at least one metal compound, the catalyst layer having opposed first and second sides; a hydrophobic gas-diffusion layer provided on the first side of the catalyst layer; a current collection structure provided on the second side of the catalyst layer. The metal is preferably copper. The invention also relates to a method for electrochemical production of a hydrocarbon product, such as ethylene, using said catalyst.

Abstract: The disclosure provides in its first aspect a catalyst system for gas-phase electrolysis of a reactant gas to form a product in an aqueous medium, the catalyst system comprising a catalytic material; an ion-conducting polymer layer provided on the catalytic material and comprising an ion-conducting polymer that includes hydrophilic and hydrophobic groups. Said catalyst system is remarkable in that the ion-conducting polymer layer has a thickness of 2 nm to 50 nm measured by transmission-electron microscopy. In its second aspect, the disclosure provides a method of manufacturing a catalyst system for gas-phase electrolysis of reactant gas to produce a product in an aqueous medium preferably according to the first aspect. The use of the catalyst system in accordance with the first aspect in the electrochemical production of at least one multi-carbon compound from a carbon-containing gas or of at least one product from a reactant gas is also disclosed.

Abstract: Disclosed herein are lattice-anchored materials that combine cesium lead halide perovskites with lead chalcogenide colloidal quantum dots (CQDs) that surprisingly exhibit stability exceeding that of the constituent materials. The CQDs keep the perovskite in its desired cubic phase, suppressing the transition to the undesired, lattice-mismatched, phases. These composite materials exhibit an order of magnitude enhancement in air stability for the perovskite, showing greater than six months' stability in room ambient as well as being stable for more than five hours at 200° C. in air. The perovskite prevents oxidation of the CQD surfaces and reduces the nanoparticles' agglomeration under 100° C. by a factor of five compared to CQD controls. The matrix-protected CQDs exhibit 30% photoluminescence quantum efficiency for a CQD solid emitting at infrared wavelengths.

Abstract: Disclosed herein are homogeneous CQD bulk homojunction solids prepared through a cascade surface modification (CSM) strategy. The CSM includes an initial halogenation step of CQD surfaces to attain an initial sufficient passivation; and a subsequent step that reprograms CQD surfaces with functional ligands to control the doping character and solubility properties of the resulting CQD inks. The resulting p-type and n-type CQDs exhibit a distinct potential difference, which induces a built-in electric field between the constituent classes of CQDs. By controlling the colloidal solubility of the inks, homogeneous CQD bulk homojunction films have been achieved, whereas it is shown that the use of prior ink strategies results in inhomogeneous films as a result of poor miscibility. The homogeneous CQD bulk homojunction films exhibit a 1.5-fold increase in the carrier diffusion length and outperforms previously-reported CQD solar cells, achieving a record PCE of 13.3%.

Abstract: The present disclosure provides a method for facet-selective passivation on each crystal facet of colloidal nanocrystals via solution-phase ligand exchange process, thereby providing highly-passivated and colloidally-stable nanocrystal inks. This ligand exchange strategy separately addresses polar and non-polar facets precluding from deleterious nanocrystal aggregation in the colloid. The method involves the introduction of alkali metal organic complexes during metal halide conventional solution exchanges, and one specific example is Na+.Ac?. Alkali metal ions stabilize and passivate non polar facets whereas polar facets are passivated through metal halides. This strategy leads to a significant decrease in nanocrystal aggregation during and after ligand exchange, and to improved photophysical properties stemming from this. The resulting nanocrystal solid films exhibit improved stability, retain their absorption features, and have a minimized Stokes shift.

Abstract: The invention relates to a composite multilayer carbon dioxide (CO2) reduction catalyst, comprising a catalyst layer comprising at least one metal compound, the catalyst layer having opposed first and second sides; a hydrophobic gas-diffusion layer provided on the first side of the catalyst layer; a current collection structure provided on the second side of the catalyst layer. The metal is preferably copper. The invention also relates to a method for electrochemical production of a hydrocarbon product, such as ethylene, using said catalyst.

Abstract: Optoelectronic devices, such as photovoltaic device and light-emitting diode, are provided. The devices include a quasi two-dimensional layered perovskite material and a passivating agent chemically bonded to the quasi two-dimensional layered perovskite material. The passivating agent includes a phosphine oxide compound. An active material is also provided. The active material includes a quasi two-dimensional perovskite compound having outermost edge(s), and a passivating agent chemically bonded to the outermost edge(s). The passivating agent includes a phosphine oxide compound. Methods for manufacturing the optoelectronics devices and the active material are also provided.