Influence of Ni doping on PtNi nanoparticles: Synthesis, electronic/atomic structure and photocatalyst investigations. (November 2017)

• Record Type: Journal Article
• Authors: Varshney, Mayora; Sharma, Aditya; Shin, Hyun-Joon; Lee, Hyun Hwi; Jeon, Tae-Yeol; Lee, Byeong-Hyeon; Chae, Keun-Hwa; Won, Sung Ok
• Is Part Of: Journal of physics and chemistry of solids. Volume 110(2017)
• Page Start: 187
• Page End: 194
• Publication Date: 2017-11
• Subjects: PtNi nanoparticles -- XANES -- EXAFS -- Photocatalyst; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2017.06.012
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Carbon-supported Pt and PtNi nanoparticles (NPs) were synthesized using a borohydride reduction method. Structural properties were studied by synchrotron X-ray diffraction (XRD) and the size/shape of the NPs was determined by transmission electron microscope (TEM). X-ray absorption spectroscopy with its two amendments; X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), has been employed to investigate the local electronic/atomic structure surrounding the Pt and Ni atoms. XANES results, at Pt L3 -edge and Ni K-edge, have shown fractional oxidation of Pt and Ni atoms. The Pt3Ni1NPs have exhibited a lower bond distance of Pt–Ni shell and higher coordination number of Pt–Ni shells, indicating the alloy formation between Pt and Ni. We further have demonstrated that the Pt and PtNi NPs can serve as effective photocatalysts towards the degradation of water pollutant dye (methyl orange (MO)). By considering the interband charge-transfer of Pt (5d →6sp), a tentative mechanism is proposed to understand the photocatalytic degradation of MO dye molecules by Pt/PtNi NPs under the light irradiation. Graphical abstract: Highlights: Pt and PtNi nanoparticles were synthesized by using modified borohydride reduction method. XRD, TEM, XANES, EXAFS and photocatalysis measurements were performed. XRD and EXAFS confirmed the PtNi alloy formation in the nanoparticles. Pt3Ni1 nanoparticles have higher coordination number of Pt-Ni and Ni-Pt shells. Photodegradation mechanism is proposed by considering the interband charge-transfer (5d to 6sp) of Pt.