One-Step Photochemical Synthesis of Transition Metal–Graphene Hybrid for Electrocatalysis

For widespread use of renewable energy such as water splitting, the development of electrocatalysts on a large-scale at a low-cost that remains safe and environmentally friendly is still a great challenge. Here, we report the use of α-aminoalkyl radicals in a one-step procedure that synthesizes transition metal nanoparticle–graphene composites via photoreduction. The organic photocatalyst 2-methyl-1-[4-(methylthio)phenyl]-2-(morpholinyl)phenyl]-1-butanone (I-907) undergoes Norrish Type I photocleavage to generate strongly reducing α-aminoalkyl radicals, when exposed to UVA. For the first time, we demonstrate its ability to reduce graphene oxide (GO) and successfully synthesize Co 3 O 4 nanoparticles decorated on graphene (Co 3 O 4 NP-rGO). The α-aminoalkyl radicals simultaneously reduce GO and Co 2+ salts, which nucleates on the negatively charged GO sheets and grows to form nanoparticles. The resulting Co 3 O 4 NP-rGO showed decent catalytic activity and stability for the oxygen evolution reaction. Our work introduces a new and environmentally friendly synthesis procedure that can be used to produce earth abundant transition metal electrocatalysts.