Exoelectrogenic biofilm as a template for sustainable formation of a catalytic mesoporous structure.
Mesoporous structures can increase catalytic activity by maximizing the ratio of surface area to volume, but current synthesis techniques utilize expensive polymers and toxic chemicals. A Geobacter sulfurreducens biofilm was used as a sustainable template to form mesoporous Pd structures while eliminating the need for synthetic chemicals. The bulk of the biofilm material was removed by thermal treatments after nanoparticle formation, producing a catalytic Pd mesoporous (pore size 9.7 ± 0.1 nm) structure attached to the graphite electrode with a 1.5-2 µm thick backbone composed of nanoparticles (∼200 nm). A control electrode electrochemically plated with Pd in the absence of a biofilm exhibited a variable planar Pd base (∼0.5-3 µm thick) with sporadic Pd extrusions (∼2 µm across, 1-5 µm tall) from the surface. The biotemplated mesoporous structure produced 15-20% higher stable current densities during H2 oxidation tests than the electrochemically plated control electrode, even though 30% less Pd was present in the biotemplated catalyst. These results indicate that electroactive biofilms can be used as a sustainable base material to produce nanoporous structures without the need for synthetic polymers. Biotechnol. Bioeng. 2014;111: 2349-2354. © 2014 Wiley Periodicals, Inc.
Department of Civil and Environmental Engineering, Pennsylvania State University, 212 Sackett Building, University Park, Pennsylvania, 16802.
Matthew D
MD
Yates
Roland D
RD
Cusick
Ivan
I
Ivanov
Bruce E
BE
Logan
D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development*; D004560:Electricity; D004566:Electrodes / Q000382:microbiology; D045302:Geobacter / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D006859:Hydrogen / Q000378:metabolism; D053758:Nanoparticles / Q000378:metabolism*; D010084:Oxidation-Reduction; D010165:Palladium / Q000378:metabolism*
D010165:Palladium; D006859:Hydrogen
biotemplate; catalytic; exoelectrogenic; mesoporous