In the present study, we successfully synthesized highly conductive
diamond/graphite nanostructures in the absence of N2
with excellent reproducibility by a microwave plasma enhanced
CVD system. The electrochemical potential window (−1.2 V–1.9 V)
is comparable with B-doped diamond electrodes, but wider than
that of the N-diamond nanostructures electrodes in the previous
literature [17]. We aim at using the electrodes for electrochemical
applications. In this context, the electrochemical behavior
of the hybrid diamond/graphite films was studied in two typical
redox systems to evaluate their capability in electrochemical
applications. Afterwards, the application of the electrode in anodic
stripping voltammetry (ASV) trace metal ions detection is demonstrated
using the model solutions containing silver and copper
ions and local tap water. It is well known that the existence of
trace heavy metal ions in drinking water strongly affects people’s
health. ASV is an electrochemical method that is widely used
to determine trace heavy metal ions concentration. Compared to
the conventional spectroscopic techniques such as atomic absorption
spectroscopy (AAS), atomic emission spectroscopy (AES) and
inductively coupled plasma mass spectrometry (ICPMS) [19,20],
ASV technique has the advantages such as rapid measurement,
convenience, low cost and the feasibility of on-site monitoring.
Therefore, we choose the ASV trace heavy metal analysis as the
application of this kind of diamond/graphite nanostructures electrochemical
electrode.