Effect of silver electrode wetting state on oxygen reduction electrochemistry.

Surface wettability plays an important role in heterogeneous electrocatalysis. Here we report a facile laser ablation strategy to directly modify the wettability of the silver catalyst surface and investigate its effect on oxygen reduction reaction (ORR). A broad range tuning of 2e-/4e- ORR pathways was achieved, with hydrophilic silver surfaces (contact angle (θw) 31.1°± 0.6°) showing high activity and selectivity towards 4e- reduction of oxygen to water.