XPS analysis for Cs adsorbed on L-cysteine/Au nanoparticle

Tsukada, Chie*; Yoshida, Hikaru; Ogawa, Satoshi*; Yoshigoe, Akitaka ; Yagi, Shinya*; Yaita, Tsuyoshi

The decontamination of radioactive Cs from the soil and the water has been required in Fukushima. Gold nanoparticles (AuNPs) are attractive candidate for Cs adsorbent. AuNPs fabricated by solution plasma method is not covered by dispersant and is almost clean. It is known that L-cysteine rapidly adsorbs and exists with high density on the AuNPs surface. The electrostatic attractive force may be useful to induce interactions between -COO- of L-cysteine and Cs ion in aqueous solution. This study reveals the adsorption reaction between the Cs and the Cys/AuNP. Cys/AuNP has a peak and CsCl/Cys/AuNP has no peak in Na 1s spectra. Cys/AuNP has no peak and CsCl/Cys/AuNP has a peak for Cs 3 spectra. From these results, Na on Cys/AuNP is replaced by Cs after reaction in CsCl aqueous solution. Cys/AuNP and CsCl/Cys/AuNP have a O 1s peak, where the peak position of CsCl/Cys/AuNP is higher than that ofCys/AuNP. This indicates the further polarization of -COO- by replacing Na by Cs.