Abstract: Halide perovskite compounds comprising at least one metal cation, at least one halide anion, and at least one alkali metal-bound crown ether, such as (crown ether@A)2M(IV)X6, (crown ether@A)M(II)X4, or (crown ether@A)M(III)X5 (A=alkali metal cation, M=metal cation, X=halide anion), such as (18C6@K)2HfBr6, (18C6@K)2ZrCl4Br2, (18C6@Ba)MnBr4, and (18C6@Ba)SbCl5 are provided. Methods of generating such halide perovskite compounds are also provided. The halide perovskite compounds provided herein can have improved photoluminescence quantum yield (PLQY), improved tunability, improved purity, and/or improved stability relative to available halide perovskite compounds such as alkali metal cation vacancy-ordered perovskites.

Abstract: This disclosure provides systems, methods, and apparatus related to photochemical diodes. In one aspect, a device include a photoanode, a photocathode, and a bipolar membrane between the photoanode and the photocathode. The photoanode comprises a first semiconductor, the first semiconductor being N-type doped, a first catalyst disposed over the first semiconductor, and the photoanode being disposed in an anolyte. The photocathode comprises a second semiconductor, the second semiconductor being P-type doped, a second catalyst disposed over the second semiconductor, and the photocathode being disposed in a catholyte. The photoanode and the photocathode are in electrical contact. A hydrogen reduction reaction or a carbon dioxide reduction reaction occurs at the photocathode and a chemical oxidation reaction occurs at the photoanode when the photocathode and the photoanode are illuminated with light.

Abstract: A method of forming a phase-pure Cs2TeX6 powder can include: dissolving a precursor TeX in a solution; rapidly adding a stoichiometric amount of respective CsX precursor to the solution, resulting in Cs2TeX6 powder immediately precipitating out of the solution; removing excess solution from the solution, resulting in the phase-pure Cs2TeX6 powder; washing the phase-pure Cs2TeX6 powder; and drying the phase-pure Cs2TeX6 powder.

Abstract: An integrated, modular system for direct air capture (DAC) and electro-microbial production (EMP) for bioelectrochemical conversion of CO2 comprises (a) a solid absorbent configured to directly capture CO2 from air; (b) a first bioreactor configured to receive enriched and purified CO2 from the absorbent and convert the CO2 to an upgradeable organic carbon intermediate by an autotrophic microorganism, wherein the autotrophic organism derives energy from oxidation of electrochemically-generated reducing equivalents; and (c) a second bioreactor configured to receive the organic carbon intermediate from the first bioreactor for use as a feedstock by a metabolically engineered microorganism to generate a value added product.

Abstract: A solution phase synthesis process for preparing a rare earth perovskite, the process includes reacting an alkali metal material with a first surfactant ligand in the presence of a first solvent to obtain a first precursor complex solution; reacting a rare earth metal halide with a second surfactant ligand in the presence of a second solvent to obtain a second precursor complex solution; and reacting the first precursor complex solution with the second precursor complex solution in the presence of a third surfactant ligand and a third solvent to obtain the rare earth perovskite; wherein: the rare earth perovskite is in the form of nanocrystals; and the first solvent and third solvent comprise a non-coordinating solvent.

Abstract: Formaldehyde is obtained from CO2 through hydrogenation of CO2 to methanol while the subsequent oxidation of methanol yields formaldehyde. This formaldehyde combined with the electrochemically produced glycolaldehyde generates sugars, thus establishing a route from CO2 to sugars.

Abstract: A solution phase synthesis process for preparing a rare earth perovskite, the process includes reacting an alkali metal material with a first surfactant ligand in the presence of a first solvent to obtain a first precursor complex solution; reacting a rare earth metal halide with a second surfactant ligand in the presence of a second solvent to obtain a second precursor complex solution; and reacting the first precursor complex solution with the second precursor complex solution in the presence of a third surfactant ligand and a third solvent to obtain the rare earth perovskite; wherein: the rare earth perovskite is in the form of nanocrystals; and the first solvent and third solvent comprise a non-coordinating solvent.

Abstract: This disclosure provides systems, methods, and apparatus related to nanoparticle/ordered-ligand interlayers. In one aspect, a structure comprises an assembly and a layer of ligands disposed on a surface of the assembly. The assembly comprises a plurality of metal nanoparticles. The metal nanoparticles of the plurality of metal nanoparticles in the assembly are proximate one another. The layer of ligands is operable to detach from the surface of the assembly but to remain proximate the surface of the assembly when the assembly is disposed in an electrolyte and a negative bias is applied to the assembly. An interlayer forms between the assembly and the layer of ligands, with the interlayer comprising desolvated cations from the electrolyte.

Abstract: The present disclosure provides devices and methods for delivering a biomolecule into a cell. A delivery device of the present disclosure includes a first reservoir, a second reservoir, a porous membrane comprising a nanopore, and two or more electrodes configured to generate an electric field across the porous membrane for delivery of a biomolecule present in the second reservoir through the nanopore of the porous membrane and into a cell present in the first reservoir.

Abstract: This disclosure provides systems, methods, and apparatus related to nanostructures. In one aspect, an array of nanowires is provided. The array of nanowires comprises a plurality of nanowires. End of nanowires of the plurality of nanowires are attached to a substrate. A liquid including a plurality of nanoparticles is deposited on the array of nanowires. The liquid is evaporated from the array of nanowires. Nanoparticles of the plurality of nanoparticles are deposited on the nanowires as a meniscus of the liquid recedes along lengths of the plurality of nanowires.

Abstract: This disclosure provides systems, methods, and apparatus related to heterojunctions in halide perovskite nanostructures. In one aspect, a nanostructure comprises a first region and a second region. The first region comprises ABX3, with A being selected from a group consisting of Cs and Rb, with B being selected from a group consisting of Sn and Pb, and with X being selected from a group consisting of Br, Cl, and Br and Cl. The second region comprises ABY3, with Y being selected from a group consisting of Br, I, and Br and I. Compositions of the first region of the nanostructure and the second region of the nanostructure are different.

Abstract: Provided are methods for synthesizing metal nanowires in solution using an organic reducing agent. A reaction mixture can be provided in solution with a metal salt, the organic reducing agent, and a solvent, where the solvent includes a surface ligand or consists of a surface ligand. The organic reducing agent, such as benzoin, can be decomposed in the reaction mixture to form organic free radicals that reduce metal ions of the metal salt into metal. The surface ligand of the solvent can coordinate with the metal in a manner so that metal nanowires are formed in solution. The diameter and morphology of the nanowires, reaction speed, reaction yield, and other features may be tunable by adjusting parameters such as reaction temperature and chemistry of the reducing agent.

Abstract: This disclosure provides systems, methods, and apparatus related to copper nanoparticle structures for reduction of carbon dioxide to multicarbon products. In one aspect, a method includes providing a plurality of copper nanoparticles. The plurality of copper nanoparticles are deposited on a support. The plurality of copper nanoparticles are transformed to a plurality of copper structures during an operation in which carbon dioxide is reduced. The plurality of copper nanoparticles on the support are used as a working electrode in an electrochemical cell during the operation.

Abstract: Described herein are bimetallic nanoframes and methods for producing bimetallic nanoframes. A method may include providing a solution including a plurality of nanoparticles dispersed in a solvent, and exposing the solution to oxygen to convert the plurality of nanoparticles into a plurality of nanoframes.

Abstract: Described herein are metallic excavated nanoframes and methods for producing metallic excavated nanoframes. A method may include providing a solution including a plurality of excavated nanoparticles dispersed in a solvent, and exposing the solution to chemical corrosion to convert the plurality of excavated nanoparticles into a plurality of excavated nanoframes.

Abstract: The disclosure provides methods to produce ultrathin metal nanowires, the metal nanowires produced therefrom, and the use of the metal nanowires as transparent conductors.

Abstract: This disclosure provides systems, methods, and apparatus related to solar water splitting. In one aspect, a structure includes a plurality of first nanowires, the plurality of first nanowires comprising an n-type semiconductor or a p-type semiconductor. The structure further includes a second nanowire, the second nanowire comprising the n-type semiconductor or the p-type semiconductor, the second nanowire being a different composition than the plurality of first nanowires. The second nanowire includes a first region and a second region, with the first region having a conductive layer disposed thereon, and each of the plurality of first nanowires being disposed on the conductive layer.

Abstract: Systems, methods, and apparatus provide integration of microscopic imaging and liquid chromatography-mass spectrometry on a microfluidic device. In one aspect, an apparatus includes a first wafer, a second wafer, and an emitter. The emitter is disposed between the first wafer and the second wafer. The first wafer defines a sample input hole. The first wafer and the second wafer define a first channel, the first channel including a first end and a second end. The first end of the first channel is proximate the sample input hole. The first channel is configured to contain separation media. The second end of the first channel is proximate the emitter.

Abstract: This disclosure provides systems, methods, and apparatus related to solar water splitting. In one aspect, a structure includes a plurality of first nanowires, the plurality of first nanowires comprising an n-type semiconductor or a p-type semiconductor. The structure further includes a second nanowire, the second nanowire comprising the n-type semiconductor or the p-type semiconductor, the second nanowire being a different composition than the plurality of first nanowires. The second nanowire includes a first region and a second region, with the first region having a conductive layer disposed thereon, and each of the plurality of first nanowires being disposed on the conductive layer.

Abstract: This disclosure provides systems, methods, and apparatus related to nanostructures. In one aspect, an array of nanowires is provided. The array of nanowires comprises a plurality of nanowires. End of nanowires of the plurality of nanowires are attached to a substrate. A liquid including a plurality of nanoparticles is deposited on the array of nanowires. The liquid is evaporated from the array of nanowires. Nanoparticles of the plurality of nanoparticles are deposited on the nanowires as a meniscus of the liquid recedes along lengths of the plurality of nanowires.