Disclosed herein is a photocatalytic filter, which includes a plurality of cross-linked polymethyl methacrylate (PMMA)/ionic liquid (IL)/TiO.sub.2 nanocomposite pellets, and a photocatalytic vessel. The plurality of cross-linked PMMA/IL/TiO.sub.2 nanocomposite pellets is placed within the photocatalytic vessel. Each cross-linked PMMA/IL/TiO.sub.2 nanocomposite pellet includes a PMMA polymeric matrix, and a plurality of IL/TiO.sub.2 core-shell microspheres dispersed within the PMMA polymeric matrix. Moreover, each IL/TiO.sub.2 core-shell microsphere includes a core of IL and a shell of TiO.sub.2 nanoparticles.

A substrate subject to degradation at temperatures above 100 C. is coated with a nanostructured ceramic coating having a thickness in excess of 100 nm, formed on a surface of the substrate, wherein a process temperature for deposition of the nanostructured coating does not exceed 90 C. The coating may be photocatalytic, photovoltaic, or piezoelectric. The coating, when moistened and exposed to ultraviolet light or sunlight, advantageously generates free radicals, which may be biocidal, deodorizing, or assist in degradation of surface deposits on the substrate after use. The substrate may be biological or organic, and may have a metallic or conductive intermediate layer.

There are provided a new type of crystal laminate of an alkaline earth metal titanate having improved catalytic activity, and a method for producing the same. The crystal laminate is provided having a crystal of the alkaline earth metal titanate as a constitutional unit, wherein the crystal being the constitutional unit is a cubic crystal, a tetragonal crystal or an orthorhombic crystal; the crystal being the constitutional unit has a primary particle diameter of 500 nm or less; and the crystal is layered with an orientation in a {100} plane direction thereof.

Catalytic pyrolysis can upcycle waste, e.g., car bumpers, to carbon nanomaterials, preferably using synthetic TiO.sub.2 nanoparticles as catalyst during pyrolysis. Analysis of the carbon nanomaterials shows that, while RGO is produced from thermal pyrolysis of car bumper waste absent TiO.sub.2, RGO spotted with carbon dots is produced in presence of TiO.sub.2 catalyst. Rutile to anatase TiO.sub.2 phase transformation and carbon nanomaterial formation can simultaneously occur during the pyrolysis. Anatase to rutile transformation may occur while TiO.sub.2 absent the bumper material. Such TiO.sub.2-CD-RGO can be used, for example in photocatalytic degradation of organic compounds, such as methylene blue.

High surface area 3D mesoporous carbon nanocomposites can be derived from Zn dust and PET bottle mixed waste with a high surface area. Simultaneous transformation of Zn metal into ZnO nanoparticles and PET bottle waste to porous carbon materials can be achieved by thermal treatment at preferably 600 to 800 C., and reaction times of from 15 to 60 minutes, after optionally de-aerating the reaction mixtures with N.sub.2 gas. The waste-based carbon materials can have surface areas of 650 to 725 m.sup.2/g, e.g., 684.5 m.sup.2/g and pore size distributions of 12 to 18 nm. The carbon materials may have 3D porous dense layers with a gradient pore structure, which may have enhanced photocatalytic performance for degrading, e.g., organic dyes, such as methylene blue and malachite green. Sustainable methods make ZnO-mesoporous carbon materials from waste for applications including photocatalysis, upcycling mixed waste materials.

In one embodiment, an antibacterial material includes at least one microparticles selected from tungsten oxide microparticles and tungsten oxide complex microparticles. The microparticles, which have undergone a test to evaluate viable cell count by inoculating in a test piece, to which the microparticles are adhered in a range of 0.02 mg/cm or more and 40 mg/cm or less, at least one bacterium selected from among Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and enterohemorrhagic Escherichia coli, and storing for 24 hours, have an antibacterial activity value R of 0.1 or more expressed by the following: R=log(B.sub.1/C.sub.1) where, B.sub.1 denotes an average value (number) of viable cell count after storing an untreated test piece for 24 hours, and C.sub.1 denotes an average value (number) of viable cell count after storing the test piece on which the microparticles are coated for 24 hours.

The invention discloses a visible light responsive tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite and an application thereof in exhaust gas treatment. The preparation method of the composite comprises the following steps: with urea as a precursor, carrying out twice calcination to obtain carbon nitride nanosheet; dispersing the carbon nitride nanosheet into methanol, sequentially adding cobalt nitrate hexahydrate and 2-methylimidazole, and carrying out a reaction to obtain a carbon nitride nanosheet composite; and calcining the carbon nitride nanosheet composite in an air atmosphere at a low temperature to obtain the tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite. The in-situ growth synthesis method can ensure that the tricobalt tetraoxide obtained by follow-up calcination is uniformly coated on the carbon nitride nanosheet to improve the catalytic performance; the low temperature calcination ensures that the carbon nitride can maintain its wrinkle state and chemical structure during the calcination process.

Disclosed herein is a method of treating an aqueous solution containing impurities including a perfluoroalkyl substance and/or a polyfluoroalkyl substance, comprising introducing the aqueous solution into a batch or semi-batch photocatalytic reactor with a microparticulate catalyst configured to reduce chain length of the perfluoroalkyl substance and/or polyfluoroalkyl substance, forming a treated aqueous stream, the reactor including a catalyst flow controller configured to automatically increase the catalyst concentration in the reactor while agitating the catalyst-containing solution during reaction, and removing catalyst particles from the treated aqueous stream to form a purified aqueous stream. In some cases, the feed to the reactor is atomized. Corresponding systems also are disclosed.

Described herein are methods of making the visible light photocatalysts without the use of templates that can comprise: (1) mixing a metal precursor, an alcohol, and a solvent to form a self assembled shapes at a temperature between the freezing point of the solvent and the boiling point of the solvent, (2) strengthening the shapes at a temperature of about 35 C. to about 300 C. for about 30 minutes to about 96 hours, and then (3) annealing the shapes at a temperature of between about 450 C. to about 750 C. for between about 4 hours to about 16 hours in a gaseous atmosphere. Also described are photocatalysts created by the described methods.

Use of Keplerate type polyoxomolybdates of the general structure Mo.sub.72M.sub.30, wherein M is selected from the group consisting of Fe, Cr, V or Mo.sub.2, for decontaminating aqueous media (water) from inorganic and organic pollutants