Electrochemical impedance spectroscopic measurement of potential of zero charge of octanethiolate-protected Au and Pd nanoparticles

Electrochemical impedance spectroscopic (EIS) method was used to determine potential of zero charge (PZC) of octanethiolate-protected Au and Pd nanoparticles (NPs) of about 2-nm and 3-nm sizes respectively. The PZC values so obtained were compared with those obtained by the more conventional differential pulse voltammetry (DPV)/z-plot method. Good agreements were found between the PZC values obtained by these two very different methods, attesting the validity of the EIS-based method whose applicability is not limited by the NP size and is therefore expected to have broader implications in terms of measuring PZC of metal NPs.

► ElS was validated for measuring the PZC of alkanethiol-protected metal NPs.
► The PZC by the EIS and DPV/Z-plot were compared for ∼2 nm Au and ∼3 nm Pd NPs.
► The EIS method is expected to be advantageous for metal NPs > 3 nm.