A method for preparing a silicate/carbon composite from attapulgite, and use of the silicate/carbon composite are disclosed. The preparation method includes: (1) with attapulgite as a raw material, preparing SiO.sub.2 with a special structure; (2) dispersing the prepared SiO.sub.2 in water to obtain a suspension, and subjecting the suspension to ultrasonic dispersion; dissolving a metal nitrate in the suspension, adding NH.sub.4Cl, and adding ammonia water dropwise to the suspension; and adding sucrose to obtain a suspension; (3) subjecting the suspension to microwave hydrothermal reaction; after the reaction is completed, centrifuging a resulting system; and separating a resulting solid; and (4) subjecting the solid to high-temperature calcination in a muffle furnace, and grinding a resulting product to obtain the silicate/carbon composite, which can be used in photocatalytic ammonia synthesis.

Disclosed apparatuses, systems, and materials relate to the disassociation of feedstock species (such as those in gaseous form) into constituent components, and may include an energy generator configured to provide a microwave energy. A first chamber defines a first volume and is configured to guide the microwave energy along the first chamber as a sinusoidal wave having an energy maxima at a point along the first chamber. A second chamber contains a plasma plume and is positioned substantially proximal to the first chamber, and is configured to enable propagation of the microwave energy through the first chamber and the second chamber such that the microwave energy demonstrates, at a radial center of the second chamber, a coaxial energy maxima configured to ignite the plasma plume contained in the second chamber. Carbon-containing materials may be formed by controlling flow parameters of the feedstock species into the first or second chamber.

In various embodiments, an air purifier capable of destroying and deactivating airborne contaminants such as SARS-CoV-2 is described. The air purifier comprises a photocatalytic system comprising at least one photoactivated semiconductor photocatalyst and a lamp configured to irradiate and excite the at least one photoactivated semiconductor photocatalyst to generate reductive and/or oxidative reactive species from oxygen and/or water on the photocatalyst surface. In various embodiments, the photocatalytic system comprises a stack of PCB cards, each card having a photocatalytic layer disposed thereon, or a 3-dimensionally ordered macroporous (3-DOM) structure comprising an open cell lattice.

A preparation method and use of a novel pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material are disclosed. The surface hydroxyl-rich metasilicic acid is used as the raw material, and by using a sulfonating reagent and/or phosphoric acid, the sulfonic acid group and/or the phosphoric acid group are bonded to the inorganic silicon material by chemical bonding to obtain a pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material. The catalytic material can be widely used in many acid-catalyzed organic reactions such as isomerization, esterification, alkylation, hydroamination of olefins, condensation, nitration, etherification, multi-component reactions and oxidation reactions. The inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material of the present invention has the advantages of high acid amount, high activity, good hydrothermal stability, no swelling, simple preparation, low cost, no pollution, no corrosion, easy separation and reusability.

The present disclosure relates to a catalyst that removes an organic compound by using a metal oxide catalyst and a preparation method thereof and a method for degradation of an organic compound using the same. Particularly, the present disclosure relates to a copper-iron oxide (Cu—Fe.sub.2O.sub.3) catalyst composition that is prepared by following steps of: adding a mixed solution of an iron (Fe) precursor and a copper (Cu) precursor to a precipitator solution (S1); obtaining precipitates by heating a solution prepared in the step S1 (S2); obtaining a metal oxalate by filtering the precipitates obtained in the step S2 (S3); drying the metal oxalate obtained in the step S3 (S4); and obtaining a copper-iron oxide catalyst by calcinating the metal oxalate subjected to the step S4 (S5) and a method for removal of an organic compound using the same.

A high-adsorption-performance nanofiber filter medium includes a support material and a composite nanofiber filtration layer that includes multiple nanometer composite nanofiber layers deposited and stacked on the support material. The nanometer composite nanofiber layer includes first, second, and third nano-powder composite nanofibers, which are uniformly mixed by means of an airflow or are sequentially laminated to form the nanometer composite nanofiber layer. The nanometer composite nanofiber layer formed through sequential lamination includes first, second, and third nanofiber layers. The first nanofiber layer includes multiple first nano-powder composite nanofibers. The second nanofiber layer is stacked on the first nanofiber layer and includes multiple second nano-powder composite nanofibers. The third nanofiber layer is stacked on the second nanofiber layer and includes multiple third nano-powder composite nanofibers. The composite nanofiber filtration layer is formed of multiple nanometer composite nanofiber layers, so that the high-adsorption-performance nanofiber air filter medium shows improved performance.

The present disclosure relates to a multi-sandwich composite catalyst and a preparation method and application thereof. The present disclosure provides a preparation method of a multi-sandwich composite catalyst, comprises the following steps: sequentially depositing a first layer oxide, a first active metal, an oxide interlayer, a second active metal and a surface oxide on a template, and sequentially performing calcination and reduction, thereby obtaining a multi-sandwich composite catalyst; wherein the first active metal and the second active metal are different kinds of active metals. In the present disclosure, a multi-sandwich structure is formed by depositing the oxides and active metals alternately, so that the position and spacing distance of the active centers can be precisely controlled. The multi-sandwich composite catalyst prepared by the method provided described herein has a higher conversion than that of a catalyst without an interlayer when used for the catalytic reaction.

Catalyst ink may be directly printed to a substrate using a stamp. Printed catalyst ink may converted to a pattern of one or more metal traces. Materials for a stamp and/or a substrate, and/or components of a catalyst ink, may be selected based on attraction of one or more of components of the catalyst ink to one or more print surfaces of the substrate and/or to one or more write surfaces of the stamp.

Proposed are a photocatalyst, including titanium dioxide particles including titanium dioxide (TiO.sub.2), a carbon material located on all or part of the surface of the titanium dioxide particles and including at least one selected from the group consisting of graphene, reduced graphene oxide (rGO), and carbon nanotubes (CNTs), and bimetallic nanoparticles supported on the carbon material and including first metal nanoparticles and second metal nanoparticles, and a water treatment method using the same. In the photocatalyst and the water treatment method using the same, the photocatalyst including bimetallic nanoparticles and graphene oxide is prepared, thereby exhibiting high reduction efficiency and high selectivity to nitrogen gas even without the use of an external electron donor.

There is provided a catalyst composition including a hydrogen oxidation catalyst and an oxygen reduction catalyst. Heat exchange reactors including the catalyst are also provided. The catalyst is adapted for low temperature activation of a hydrogen combustion reaction.