As(Ⅲ) standard solution, acetic acid, sodium acetate trihydrate, and iron, lead, copper standard solutions were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). Potassium tetrachloroaurate (Ⅲ) was purchased from Sigma-Aldrich (St. Louis, MI, USA). Pt wire and Ag/AgCl electrode (BAS Inc., Tokyo, Japan) were used as the counter and reference electrodes for the electrochemical measurements, respectively.
Electrochemical measurements were performed using an electrochemical analyzer (ALS 832D, BAS Inc., Tokyo, Japan). Scanning electron microscopy (SEM) was performed using JSM-9100F (JEOL Ltd., Tokyo, Japan) and Ultra Plus (Carl Zeiss Microscopy GmbH). Energy-dispersive X-ray spectroscopy (EDX) was performed using a spectrometer manufactured by Oxford Instruments (Abingdon-on-Thames, UK) and XFlash 6-30 (Bruker Nano GmbH, Berlin, Germany). X-ray diffraction (XRD) of the materials was performed using SmartLab (Rigaku, Tokyo, Japan). X-ray photoelectron spectroscopy (XPS) of the electrode surface was performed using AXIS-165 (Shimadzu Corporation, Kyoto, Japan).
Electrochemical measurements were performed using an electrochemical analyzer (ALS 832D, BAS Inc., Tokyo, Japan). Scanning electron microscopy (SEM) was performed using JSM-9100F (JEOL Ltd., Tokyo, Japan) and Ultra Plus (Carl Zeiss Microscopy GmbH). Energy-dispersive X-ray spectroscopy (EDX) was performed using a spectrometer manufactured by Oxford Instruments (Abingdon-on-Thames, UK) and XFlash 6-30 (Bruker Nano GmbH, Berlin, Germany). X-ray diffraction (XRD) of the materials was performed using SmartLab (Rigaku, Tokyo, Japan). X-ray photoelectron spectroscopy (XPS) of the electrode surface was performed using AXIS-165 (Shimadzu Corporation, Kyoto, Japan).