Abstract: Included herein are methods for photodriven hydrogenation of N2, the methods comprising, for example: hydrogenating N2 to NH3 in the presence of a light, an organic transfer agent, and a first metal-containing catalyst; wherein: the transfer agent and the first catalyst are in a solution; the transfer agent comprises n chemically transferable electrons and protons, n being an integer equal to or greater than 1; the step of hydrogenating comprises at least one charge-transfer reaction via which the transfer agent donates at least one electron and at least one proton to one or more other chemical species; the step of hydrogenating comprises at least one photochemical reaction; and the light is characterized by energy sufficient to drive the at least one photochemical reaction. Also disclosed herein are methods comprising regenerating a spent-transfer agent back into the transfer agent.