Abstract: A method of preparing a metal nanoparticle can include depositing an ink on a substrate using nanolithography to form a polymer reactor, wherein the ink comprises at least one metalloporphyrin functionalized polymer comprising a metal ion, porphyrin, and a polyethylene oxide polymer; and thermally annealing the polymer nanoreactor under conditions sufficient to form the nanoparticle. The thermal annealing can include a first stage that includes annealing the polymer nanoreactor at a temperature of about 100° C. to about 350° C. for a time sufficient to aggregate the metal ions in the polymer reactor, and a second stage that includes annealing the aggregated polymer nanoreactor at a temperature of about 500° C. to about 600° C. for a time sufficient to reduce the metal ion and decompose a polymer component of the polymer nanoreactor to thereby form the metal nanoparticle.

Abstract: A method of forming a halide perovskite nanocrystal array having a plurality of halide perovskite nanocrystals arranged in a pattern can include coating an array of pens with a first ink comprising at least one first perovskite precursor having the formula AX and at least one second perovskite precursor having the formula BX?2 dissolved in a solvent. A is a cation, B is a metal, and X and X? are each a halogen. The method further includes contacting a substrate with the coated pen array to thereby deposit the first ink indias a pattern of printed indicia on the substrate. The printed indicia form nanoreactors on the substrate and a halide perovskite nanocrystal nucleates and grows within each nanoreactor to form the halide perovskite nanocrystal array.

Abstract: Electrocatalytic materials and methods of making the electrocatalytic materials are provided. Such a method may comprise forming precursor nanosheets comprising a precursor metal on a surface of a substrate; exposing the precursor nanosheets to a modifier solution comprising a polar, aprotic solvent and a metal salt at a temperature and for a period of time, the metal salt comprising a metal cation and an anion, thereby forming modified precursor nanosheets; and calcining the modified precursor nanosheets for a period of time to form an electrocatalytic material comprising structurally modified nanosheets and the substrate, each nanosheet extending from the surface of the substrate and having a solid matrix.

Abstract: A method of preparing a metal nanoparticle can include depositing an ink on a substrate using nanolithography to form a polymer reactor, wherein the ink comprises at least one metalloporphyrin functionalized polymer comprising a metal ion, porphyrin, and a polyethylene oxide polymer; and thermally annealing the polymer nanoreactor under conditions sufficient to form the nanoparticle. The thermal annealing can include a first stage that includes annealing the polymer nanoreactor at a temperature of about 100° C. to about 350° C. for a time sufficient to aggregate the metal ions in the polymer reactor, and a second stage that includes annealing the aggregated polymer nanoreactor at a temperature of about 500° C. to about 600° C. for a time sufficient to reduce the metal ion and decompose a polymer component of the polymer nanoreactor to thereby form the metal nanoparticle.