Microbial synthesis of highly dispersed PdAu alloy for enhanced electrocatalysis

Biosynthesis based on the reducing capacity of electrochemically active bacteria is frequently used in the reduction of metal ions into nanoparticles as an eco-friendly way to recyclemetal resources. However, those bionanoparticles cannot be used directly as electrocatalysts because of the poor conductivity of cell substrates. This problemwas solved by a hydrothermal reaction, which also contributes to the heteroatomdoping and alloying between Pd and Au. With the protection of graphene, the aggregation of nanoparticles was successfully avoided, and the porous structure was maintained, resulting in better electrocatalytic activity and durability than commercial Pd/C under both alkaline (CH3CH2OH, 6.15-fold ofmass activity) and acidic (HCOOH, 6.58-fold ofmass activity) conditions. The strategy developed in this work opens up a horizon into designing electrocatalysts through fully utilizing the abundant resources in nature.