The water decomposition reactions on boron-doped diamond electrodes

Journal of the Brazilian Chemical Society

Hugo B Suffredini¹  Sérgio A. S Machado¹  Luis A Avaca¹ 

[1],Universidade de São Paulo Instituto de Química de São Carlos São Carlos SP ,Brazil

关键词: boron-doped diamond electrode;    hydrogen evolution reaction;    oxygen evolution reaction;    water decomposition;   

DOI  :  10.1590/S0103-50532004000100004

来源: SciELO

【 摘 要 】

The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD) electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol-1, indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol-1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material.

【 授权许可】

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