Thermoplasmonic In Situ Fabrication of Nanohybrid Electrocatalysts over Gas Diffusion Electrodes for Enhanced H₂O₂ Electrosynthesis

Large-scale development of electrochemical cells is currentlyhinderedby the lack of Earth-abundant electrocatalysts with high catalyticactivity, product selectivity, and interfacial mass transfer. Herein,we developed an electrocatalyst fabrication approach which respondsto these requirements by irradiating plasmonic titanium nitride (TiN)nanocubes self-assembled on a carbon gas diffusion layer in the presenceof polymeric binders. The localized heating produced upon illuminationcreates unique conditions for the formation of TiN/F-doped carbonhybrids that show up to nearly 20 times the activity of the pristineelectrodes. In alkaline conditions, they exhibit enhanced stability,a maximum H2O2 selectivity of 90%, and achievea H2O2 productivity of 207 mmol g(TiN) (-1) h(-1) at 0.2 V vs RHE. A detailedelectrochemical investigation with different electrode arrangementsdemonstrated the key role of nanocomposite formation to achieve highcurrents. In particular, an increased TiO x N y surface content promoted a higherH(2)O(2) selectivity, and fluorinated nanocarbonsimparted good stability to the electrodes due to their superhydrophobicproperties.