Methods and systems directed to the separation of tritium from an aqueous stream are described. The separation method is a multi-stage method that includes a first stage during which tritium of a tritium-contaminated aqueous stream is adsorbed onto a separation phase, a second stage during which the adsorbed tritium is exchanged with hydrogen in a gaseous stream to provide a gaseous stream with a high tritium concentration, and a third stage during which the tritium of the gaseous stream is separated from the gaseous stream as a gaseous tritium product.

A method for recovering isotopologues from a gas stream is provided with a wet scrubber column, which includes a liquid inlet, a liquid outlet, a gas inlet, a gas outlet, and a plurality of bubble cap trays. An initial gas stream is enriched with isotopologues, while an initial aqueous liquid is depleted of isotopologues. The initial gas stream is countercurrently contacting the initial aqueous solution through the bubble cap trays as the initial gas stream traverses from the gas inlet to the gas outlet and as the initial aqueous liquid traverses from the liquid inlet to the liquid outlet. A processed gas stream is then captured from the gas outlet and is depleted of isotopologues. Simultaneously, a processed aqueous liquid is captured from the liquid outlet and is enriched with isotopologues.

A method of synthesizing TiO.sub.2/Co.sub.3O.sub.4 core-shell photocatalysts is provided. The method includes preparing SiO.sub.2 hollow nanospheres via sol-gel synthesis in the presence of a triblock copolymer surfactant and a cationic surfactant; adding titanium sec-butoxide to a solution containing the SiO.sub.2 hollow nanospheres to provide a first combined sample; calcinating the first combined sample to provide hollow mesoporous TiO.sub.2 nanospheres; adding cobalt nitrate to a solution comprising the hollow mesoporous TiO.sub.2 nanospheres to provide a second combined sample; and calcinating the second combined sample to provide TiO.sub.2/Co.sub.3O.sub.4 core-shell photocatalysts. Methods of producing hydrogen by water-splitting using TiO.sub.2/Co.sub.3O.sub.4 core-shell photocatalysts are also provided. Such methods include photodepositing platinum onto the photocatalysts during the reaction.

A liquid phase catalytic exchange column with a catalyst is configured to receive hydrogen gas. The system uses the catalyst to exchange the hydrogen gas with the tritiated source yielding HT gas and tritiated water. The system monitors tritium content of the tritiated water. When a predetermined tritium level is detected, the tritiated water is released. The system also includes a gaseous permeation system comprising a permeable barrier for the selective extraction of gases.

A liquid phase catalytic exchange column with a catalyst is configured to receive hydrogen gas. The system uses the catalyst to exchange the hydrogen gas with the tritiated source yielding HT gas and tritiated water. The system monitors tritium content of the tritiated water. When a predetermined tritium level is detected, the tritiated water is released. The system also includes a gaseous permeation system comprising a permeable barrier for the selective extraction of gases.

Methods and systems directed to the separation of tritium from an aqueous stream are described. The separation method is a multistage method that includes a purification stage during which tritium of a tritium-contaminated aqueous stream is adsorbed onto a cooled and wet separation phase, a regeneration stage during which the adsorbed tritium is exchanged with hydrogen in a gaseous stream to regenerate the separation phase and provide a gaseous stream with a high tritium concentration, and a third stage during which the tritium of the gaseous stream is separated from the gaseous stream as a gaseous tritium product.

Methods and systems directed to the separation of tritium from an aqueous stream are described. The separation method is a multistage method that includes a purification stage during which tritium of a tritium-contaminated aqueous stream is adsorbed onto a cooled and wet separation phase, a regeneration stage during which the adsorbed tritium is exchanged with hydrogen in a gaseous stream to regenerate the separation phase and provide a gaseous stream with a high tritium concentration, and a third stage during which the tritium of the gaseous stream is separated from the gaseous stream as a gaseous tritium product.

A multicomponent photocatalyst includes a reactive component optically, electronically, or thermally coupled to a plasmonic material. A method of performing a catalytic reaction includes loading a multicomponent photocatalyst including a reactive component optically, electronically, or thermally coupled to a plasmonic material into a reaction chamber; introducing molecular reactants into the reaction chamber; and illuminating the reaction chamber with a light source.

A multicomponent photocatalyst includes a reactive component optically, electronically, or thermally coupled to a plasmonic material. A method of performing a catalytic reaction includes loading a multicomponent photocatalyst including a reactive component optically, electronically, or thermally coupled to a plasmonic material into a reaction chamber; introducing molecular reactants into the reaction chamber; and illuminating the reaction chamber with a light source.

Methods and systems for the separation of hydrogen isotopes from one another are described. Methods include utilization of a hydrogen isotope selective separation membrane that includes a hydrogen isotope selective layer (e.g., graphene) and a hydrogen ion conductive supporting layer. An electronic driving force encourages passage of isotopes selectively across the membrane at an elevated separation temperature to enrich the product in a selected hydrogen isotope.