Inconsistency of BDD reactivity assessed by ferri/ferro-cyanide redox system and electrocatalytic degradation capability

Ferri/ferro-cyanide ([Fe(CN)6]3−/4−) redox couple has been extensively used as a benchmark to assess electrocatalytic degradation capability of boron-doped diamond (BDD) electrodes. However, the [Fe(CN)6]3−/4− is far more sensitive surface terminal groups BDD than other factors (e.g. morphology and electrode configuration) that are closely related properties. Thus, inconsistency exists while correlating properties with electrochemical determined from ferri/ferro-cyanide couple. Herein, an exemplar pollutant, reactive blue 19 (RB-19), was electrochemically degraded using various terminated electrodes, including hydrogen-terminated (H-BDD), oxygen-terminated (O-BDD) porous BDDs (OE-BDD), obtained via cathodic anodic polarization well oxygen plasma etching, respectively. Surprisingly, OE-BDD lower heterogeneous electron transfer rate constant for showed better toward RB-19, indicating qualitatively evaluating according kinetic parameters extracted system.