Electrocatalytic activity of undoped and Mn-doped Zn(S,Se)-carbon nanocomposites

Electrocatalytic materials for applications, e.g. in fuel cells are often composites of (conducting) carbon variants and nanosized metal particles, typically from the family of platinum or nickel. They share some common problems (most notably a tendency to agglomeration and poisoning, e.g. by CO or H(2)), which prevent their use in contact with, e.g. raw biogenic methane or ethanol. Highly purified fuels or reformation to hydrogen are therefore necessary for such purposes. As a potential alternative, this study describes electrocatalytic activity of composites of undoped and Mn-doped Zn(S,Se) nanoparticles and carbon in contact with ethanol. The results on ethanol oxidation on such electrodes in short-circuit mode are reported, as well as values for the open circuit voltage achieved so far. The focus of this report is the variation of the Se/S ratio in mixed nanocrystals of ZnS and ZnSe. The influence on the electrocatalytic activity by the varying band gap energy and absolute positions of the electronic levels of the doped as well as undoped chalcogenide nanoparticles is reported.