Pd-Based Metal Aerogels with Promoted Bioelectrocatalytic Behavior
Here the controlled growth of Pd aerogels has been facilely realized by using calcium ions as the destabilizing agent. The involving Pd aerogels with different porosities and surface areas exhibited faster electrode kinetics and higher activities towards the bioelectrooxidation of glucose when co-immobilized with glucose oxidase (GOD), compared to the Pd NPs and glassy carbon. Based on the Pd aerogels promoted bioelectrocatalysis, we have developed a newly designed metal aerogel-based biofuel cell system. In the text, a commonly used mediator, ferrocenecarboxylic acid (Fc), was integrated into the Pd hydrogel and thus produced a Pd-Fc composite aerogel mediator for GOD at the bioanode. Additionally, bilirubin oxidase (BOD) encapsulated into a Pd-Pt alloy aerogel played a synergetic role towards the reduction of O2, which promoted the direct electrocatalytic reduction of O2 at the biocathode with an onset potential of 0.56 V under neutral conditions. By employing these two bioelectrodes, the assembled membrane-less glucose/O2 biofuel cell showed a maximum power output of 20 μW cm-2 at 0.25 V.[4,5]
 N. Gaponik, A.-K. Herrmann, A. Eychmüller, J. Phys. Chem. Lett. 2012, 3, 8–17.
 Gao, F.; Viry, L.; Maugey, M.; Poulin, P.; Mano, N. Nat. Commun. 2010, 1, 2.
 D. Wen, A.-K. Herrmann, L. Borchardt, F. Simon, W. Liu, S. Kaskel, A. Eychmüller, J. Am. Chem. Soc. 2014, 136, 2727–2730.
 W. Liu, P. Rodriguez, L. Borchardt, A. Foelske, J. Yuan, A.-K. Herrmann, D. Geiger, Z. Zheng, S. Kaskel, N. Gaponik, R. Kötz, T. Schmidt, A. Eychmüller, Angew. Chem., Int. Ed. 2013, 52, 9849–9852.