Doped graphene can be used as an electrocatalyst for different reactions. A variety of different elements has been used in doped graphene, and in most cases, the catalytic activity was improved. Doping graphene with multiple elements also generally improves its electrocatalytic performance.

Martin Pumera, University of Chemistry and Technology, Prague, and Brno University of Technology, both Czech Republic, and China Medical University, Taichung, Taiwan, and colleagues have taken it a step further: in an effort to see whether pretty much any doping could improve the catalytic properties of graphene, the team used chicken guano as a dopant. This material is cheap and contains several elements that have previously been used to dope graphene, e.g., nitrogen, sulfur, and phosphorus. The team synthesized graphite oxide using either the Hoffmann or the Hummers method and mixed it with dry guano. The mixture was then subjected to thermal exfoliation to give the desired graphene/guano composite.

The researchers found that the graphenes prepared in the presence of guano were doped with a variety of elements, mostly N, S, and P. All graphene samples have improved electrocatalytic properties for the oxygen reduction reaction (ORR) and the hydrogen evolution reaction (HER) compared with control samples prepared without guano. According to the team, this work shows that complex multielemental doping procedures for graphene might be unnecessary when such a simple, low-cost treatment provides high-performing electrocatalysts.

• Will Any Crap We Put into Graphene Increase Its Electrocatalytic Effect?,
  Lu Wang, Zdenek Sofer, Martin Pumera,
  ACS Nano 2020.
  https://doi.org/10.1021/acsnano.9b00184