A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

Systems and methods of synthesizing nanoparticles on substrates using rapid, high temperature thermal shock. A method involves depositing micro-sized particles or salt precursors on a substrate, and applying a rapid, high temperature thermal shock to the micro-sized particles or the salt precursors to become nanoparticles on the substrate. A system may include a rotatable member that receives a roll of a substrate sheet having micro-sized particles or salt precursors; a motor that rotates the rotatable member so as to unroll the substrate; and a thermal energy source that applies a short, high temperature thermal shock to the substrate. The nanoparticles may be metallic, ceramic, inorganic, semiconductor, or compound nanoparticles. The substrate may be a carbon-based substrate, a conducting substrate, or a non-conducting substrate. The high temperature thermal shock process may be enabled by electrical Joule heating, microwave heating, thermal radiative heating, plasma heating, or laser heating.

A composition that absorbs oxygen and emits carbon dioxide in response to absorbing oxygen including ascorbic acid, an organic acid, a catalyst that promotes oxidation of the organic acid and emission of carbon dioxide and a soluble transition metal salt characterized by multiple oxidation states.

A composition that absorbs oxygen and emits carbon dioxide in response to absorbing oxygen including ascorbic acid, an organic acid, a catalyst that promotes oxidation of the organic acid and emission of carbon dioxide and a soluble transition metal salt characterized by multiple oxidation states.

A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

Present subject matter provides a semiconductor nanocrystal comprises a core and a shell. The core is fabricated from a first semiconductor. The shell is fabricated from a second semiconductor. The optical cross section of the semiconductor nanocrystal is in a range of 10.sup.−17 cm.sup.2-10.sup.−12 cm.sup.2 in a 2-3 eV region. The core is less than 2 nanometers from an outer surface of the shell in at least one region of the semiconductor nanocrystal. Present subject matter also provides method for preparation of the semiconductor nanocrystals and method for photosynthesis of organic compounds.

The present disclosure relates to a method and an apparatus for treating, sorting and recycling an oil-containing discharged catalyst. There is provided a method for treating, sorting and recycling an oil-containing discharged catalyst, wherein the method comprises the following steps: (A) cyclonic washing and on-line activation of a discharged catalyst; (B) cyclonic spinning solvent stripping of the catalyst; (C) gas stream acceleration sorting of a high activity catalyst; (D) cyclonic restriping and particle capture of the high activity catalyst; and (E) cooling of the gas and condensation removal of the solvent. There is further provided an apparatus for treating, sorting and recycling an oil-containing discharged catalyst.

Provided is a method of manufacturing a porous core-shell catalyst structure. The method of manufacturing a porous core-shell catalyst structure includes preparing a bulk metal oxide; providing a first reaction gas containing nitrogen to the bulk metal oxide to prepare an intermediate product containing a porous metal oxide; and providing a second reaction gas containing sulfur to the intermediate product to prepare a core-shell catalyst structure including a core formed of the porous metal oxide and a shell formed of metal sulfide.

Provided is a method of manufacturing a porous core-shell catalyst structure. The method of manufacturing a porous core-shell catalyst structure includes preparing a bulk metal oxide; providing a first reaction gas containing nitrogen to the bulk metal oxide to prepare an intermediate product containing a porous metal oxide; and providing a second reaction gas containing sulfur to the intermediate product to prepare a core-shell catalyst structure including a core formed of the porous metal oxide and a shell formed of metal sulfide.