The Grain Size Influence on Boron Doped Diamond Sensitivity for Nitrate Electrochemical Reduction

Abstract

The grain size influence on boron doped diamond (BDD) sensitivity for nitrate electrochemical reduction was analyzed for films grown at different growth times. Scanning electron and atomic force microscopy analyses showed that the BDD film grown at longer times has larger grain size and higher surface roughness. The grain size effect on BDD sensitivity for nitrate reduction was analyzed by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements carried out in solutions with and without nitrate ions. BDD films grown at 10 h showed highest sensitivity for nitrate reduction, which is associated to the grain size increase that favors a decrease of the sp2 bonded carbon amount at its grain boundary that turning BDD surface more stable to oxidation process.