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.

Abstract: This disclosure provides systems, methods, and apparatus related to artificial photosynthesis. In one aspect a system includes a photoanode chamber including a photoanode assembly, a photocathode chamber including a photocathode assembly, an electrical connection electrically connecting the photoanode assembly and the photocathode assembly, a membrane separating the photoanode chamber and the photocathode chamber, and a microorganism disposed in the photocathode chamber. The photoanode assembly is operable to oxidize water to generate oxygen, protons, and electrons. The membrane is permeable to the protons and operable to allow the protons to travel to the photocathode chamber. The electrical connection provides electrons to the photocathode assembly. The microorganism comprises a metabolic pathway to reduce carbon dioxide and to generate a carbon-based compound using the electrons or hydrogen formed by two protons.

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: 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 for transparent conductors comprised of metal-reduced graphene oxide or graphene core-shell nanowires, process of preparation thereof, and methods of use thereof.

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: The present invention provides for a genetically modified microorganism capable of photosynthesizing an organic compound from carbon dioxide, wherein the microorganism comprises a semiconductor nanoparticle on the surface of the microorganism.

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: One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as “nanowires”, include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

Abstract: The present invention provides for a structure comprising a plurality of emitters, wherein a first nozzle of a first emitter and a second nozzle of a second emitter emit in two directions that are not or essentially not in the same direction; wherein the walls of the nozzles and the emitters form a monolithic whole. The present invention also provides for a structure comprising an emitter with a sharpened end from which the emitter emits; wherein the emitters forms a monolithic whole. The present invention also provides for a fully integrated separation of proteins and small molecules on a silicon chip before the electrospray mass spectrometry analysis.

Abstract: This disclosure provides systems, methods, and apparatus related to inorganic halide perovskite nanowires. In one aspect, a first solution comprising cesium oleate or rubidium oleate in a first organic solvent is provided. A second solution comprising a lead halide and a surfactant in a second organic solvent is provided. The halide is selected from a group consisting of chlorine, bromine, and iodine. The first solution and the second solution are mixed. A reaction between the cesium oleate or the rubidium oleate and the lead halide forms a plurality of nanowires comprising an inorganic lead halide perovskite.