Abstract: A modified side-emitting optical fiber includes a core comprising an optical fiber and a UV-C transparent polymer coating over the core. An average surface roughness of the UV-C transparent polymer coating is in a range of about 0.3 ?m to about 0.7 ?m as measured by root mean square of distance difference measurements of the surface of the UV-C transparent polymer coating. Fabricating a modified side-emitting optical fiber includes contacting a coated optical fiber with a solvent, wherein the coated optical fiber comprises a UV-C transparent polymer coating, and dissolving at least a portion of the UV-C transparent polymer coating in the solvent to yield the modified side-emitting optical fiber, wherein an average surface roughness of the UV-C transparent polymer coating is in a range of about 0.3 ?m to about 0.7 ?m.

Abstract: A composite material includes an adsorbent support having a carbon block structure defining pores, and titanium (hydr)oxide particles or films bound to the carbon block structure inside the pores. Preparing the composite material includes contacting a porous support having a carbon block structure defining pores with a solution including a solvent and a titanium (hydr)oxide precursor to yield a precursor material, and drying the precursor material to yield a titanium (hydr)oxide-impregnated carbon block. Synthesizing hybrid titanium (hydr)oxides includes combining a solution including a titanium (hydr)oxide precursor and a solvent with one or more metal precursors to yield a precursor solution, and heating the precursor solution to yield the hybrid titanium (hydr)oxides.

Abstract: Producing biomass includes providing a gas including carbon dioxide to a reaction chamber including a reaction medium, photocatalytically converting the carbon dioxide in the reaction medium into organic carbon-containing compounds, growing the bacteria in the reaction medium, and harvesting the bacteria. The reaction medium is an aqueous mixture including bacteria and trace elements. Photocatalytically converting carbon dioxide includes providing light to side-emitting optical fibers positioned in the reaction medium. An air purification system includes a single reaction chamber configured to contain bacteria, first and second inlets, one or more side-emitting optical fibers, and an outlet configured to allow harvesting of the bacteria.

Abstract: A coated optical fiber includes a polymeric side-emitting optical fiber, a cladding along a length of the polymeric side-emitting optical fiber, an electrically conductive nanomaterial in contact with the cladding, and a coating over the cladding. The coating includes a photocatalyst.

Abstract: An optical fiber reactor includes a reaction chamber defining an inlet at a first end of the reaction chamber and an outlet at a second end of the reaction chamber, a multiplicity of side-emitting optical fibers extending from the first end toward the second end, and a light source optically coupled to the optical fibers and configured to irradiate the photocatalyst on the multiplicity of side-emitting optical fibers from an interior of each of the optical fibers at a selected wavelength. The inlet is configured to receive an input gas including a contaminant and the outlet is configured to allow egress of a treated gas from the reaction chamber. The exterior surface of each optical fiber of the multiplicity of optical fibers is coated with a photocatalyst, which is configured to reduce a concentration of the contaminant in the reaction chamber through photocatalytic oxidation or reduction of the contaminant.

Abstract: A reactor for photocatalytic reduction of carbon dioxide includes a first reactor, a second reactor, and a light source. The first reactor includes a multiplicity of hollow-fiber membranes. The first reactor is configured to solubilize gaseous carbon dioxide to yield aqueous carbon dioxide. The second reactor is in fluid communication with the first reactor and includes a side-emitting polymeric optical fiber with a photocatalytic coating. The second reactor is configured to accept the aqueous carbon dioxide and the photocatalytic coating includes an iron-based metal-organic framework. The light source is optically coupled to the side-emitting polymeric optical fiber. Reducing carbon dioxide includes solubilizing gaseous carbon dioxide to yield aqueous carbon dioxide, contacting a side-emitting polymeric optical fiber including a photocatalytic coating with the aqueous carbon dioxide, and providing visible radiation to the side-emitting polymeric optical fiber, thereby reducing the aqueous carbon dioxide.

Abstract: A modified side-emitting optical fiber includes a core comprising an optical fiber and a UV-C transparent polymer coating over the core. An average surface roughness of the UV-C transparent polymer coating is in a range of about 0.3 ?m to about 0.7 ?m as measured by root mean square of distance difference measurements of the surface of the UV-C transparent polymer coating. Fabricating a modified side-emitting optical fiber includes contacting a coated optical fiber with a solvent, wherein the coated optical fiber comprises a UV-C transparent polymer coating, and dissolving at least a portion of the UV-C transparent polymer coating in the solvent to yield the modified side-emitting optical fiber, wherein an average surface roughness of the UV-C transparent polymer coating is in a range of about 0.3 ?m to about 0.7 ?m.

Abstract: An electrode includes an electrically conductive substrate with a coating containing boron-doped diamond (BDD) nanoparticles. Fabricating the electrode can include dispersing BDD nanoparticles in a solvent to yield a suspension, coating a conductive substrate with the suspension, and drying the suspension to yield the electrode. In some cases, fabricating the electrode includes combining BDD nanoparticles with a polymeric resin precursor to yield a mixture including a metal oxide, coating a conductive substrate with the mixture to yield a coated substrate, and calcining the coated substrate to yield a metal oxide coating including BDD nanoparticles.

Abstract: A photocatalytic reactor includes a polymeric side-emitting optical fiber having a coating with a photocatalyst embedded in a porous polymer, a light source optically coupled to the polymeric side-emitting optical fiber and configured to irradiate the photocatalyst, and a multiplicity of oxygen-permeable hollow-fiber membranes. The polymeric side-emitting optical fiber and the multiplicity of oxygen-permeable hollow-fiber membranes are configured to be at least partially immersed in water. When at least partially immersed in water, the multiplicity of oxygen-permeable hollow-fiber membranes is configured to provide dissolved molecular oxygen to the water, and the coating is configured to allow diffusion of the dissolved molecular oxygen into the coating and to allow diffusion of hydrogen peroxide out of the coating.

Abstract: An electrode includes an electrically conductive substrate with a coating containing boron-doped diamond (BDD) nanoparticles. Fabricating the electrode can include dispersing BDD nanoparticles in a solvent to yield a suspension, coating a conductive substrate with the suspension, and drying the suspension to yield the electrode. In some cases, fabricating the electrode includes combining BDD nanoparticles with a polymeric resin precursor to yield a mixture including a metal oxide, coating a conductive substrate with the mixture to yield a coated substrate, and calcining the coated substrate to yield a metal oxide coating including BDD nanoparticles.

Abstract: A coated optical fiber includes an optical fiber having a core and an outer surface, and a homogeneous polymer coating in contact with the outer surface of the optical fiber. The optical fiber and the homogeneous polymer coating are UV transparent, and a refractive index of the outer surface of the optical fiber or the homogeneous polymer coating is up to 15% less than a refractive index of the core. Coating the optical fiber includes coating an outer surface with a polymerizable material and polymerizing the polymerizerable material to yield the coated optical fiber having a homogeneous polymer coating. The optical fiber and the homogeneous polymer coating are UV transparent, and a refractive index of the outer surface of the optical fiber or the homogeneous polymer coating is up to 15% less than a refractive index of a core of the optical fiber.

Abstract: A composite material includes one or more side-emitting optical fibers arranged in a pattern defining openings bounded at least in part by the one or more side-emitting optical fibers. The one or more side-emitting optical fibers have a UV-C transparent coating, and at least one of the one or more side-emitting optical fibers is configured to be coupled to a light-emitting diode. A reverse osmosis filter includes a reverse osmosis membrane and the composite material coupled to the reverse osmosis membrane.

Abstract: Quantifying nanobubbles in solution includes combining an indicator with a fluid comprising nanobubbles to yield a first solution, bursting the nanobubbles in the first solution to yield a second solution, and assessing a difference between the first solution and the second solution to yield a concentration of the nanobubbles in the first solution, a concentration of reactive oxygen species in the first solution or the second solution, or both.

Abstract: A reactor for water splitting or water treatment includes a first electrode, a second electrode electrically coupled to the first electrode, and a proton exchange membrane separating the first electrode and the second electrode. The first electrode includes a first optical fiber coated with a photocatalytic material.

Abstract: A photoreactor including a reservoir configured to hold water, the reservoir defining an inlet and an outlet, and a multiplicity of optical fiber assemblies positioned in the reservoir. Each optical fiber assembly includes one or more optical fibers coated with a composition comprising a photoresponsive polymer and a light source optically coupled to the one or more optical fibers. The photoresponsive polymer undergoes a change from an initial state to an irradiated state when irradiated with light from the light source, and photoresponsive polymer in the irradiated state is adapted to bind an ion from the water.

Abstract: A water-disinfecting apparatus includes a vessel with a cathode, an insert with a photoanode, an ultraviolet light source configured to be positioned in the insert, and a power source. The cathode forms an electrically conductive layer on an inner surface of the vessel. The photoanode is configured to be positioned in the cathode. The power source is configured to be operably coupled to the cathode, the photoanode, and the light source.

Abstract: A coated optical fiber includes an optical fiber having a core and an outer surface, and a homogeneous polymer coating in contact with the outer surface of the optical fiber. The optical fiber and the homogeneous polymer coating are UV transparent, and a refractive index of the outer surface of the optical fiber or the homogeneous polymer coating is up to 15% less than a refractive index of the core. Coating the optical fiber includes coating an outer surface with a polymerizable material and polymerizing the polymerizerable material to yield the coated optical fiber having a homogeneous polymer coating. The optical fiber and the homogeneous polymer coating are UV transparent, and a refractive index of the outer surface of the optical fiber or the homogeneous polymer coating is up to 15% less than a refractive index of a core of the optical fiber.

Abstract: A method for preparing a nano-enabled activated carbon block, a nano-enabled activated carbon block produced by the method, a household water filtration system comprising the nano-enabled activated carbon block, and a method for filtering tap water using the household water filtration system are provided. The method includes contacting a solution including a metal(lic) precursor (e.g. a titanium compound and/or an iron compound and/or a zirconium compound) with activated carbon particles such that the solution fills pores of the activated carbon particles. The method further includes causing a metal (hydr)oxide (e.g. titanium dioxide and/or zirconium dioxide and/or iron oxide) to precipitate from the solution thereby causing metal oxide nanoparticles to become deposited within pores of the activated carbon particles. The method also includes preparing a nano-enabled activated carbon block from the activated carbon particles having metal oxide nanoparticles deposited within the pores thereof.

Abstract: Quantifying nanobubbles in solution includes combining an indicator with a fluid comprising nanobubbles to yield a first solution, bursting the nanobubbles in the first solution to yield a second solution, and assessing a difference between the first solution and the second solution to yield a concentration of the nanobubbles in the first solution, a concentration of reactive oxygen species in the first solution or the second solution, or both.

Abstract: A water-disinfecting apparatus includes a vessel with a cathode, an insert with a photoanode, an ultraviolet light source configured to be positioned in the insert, and a power source. The cathode forms an electrically conductive layer on an inner surface of the vessel. The photoanode is configured to be positioned in the cathode. The power source is configured to be operably coupled to the cathode, the photoanode, and the light source.