Fig. 1: XANES spectra of the Samples.

SUPPLEMENTARY INFORMATION

111Equation Chapter 1 Section 1A crystallization and structural study of the compound Pb2V2O7 synthesized by a facile sol-gel based chemical route

A. Suárez-Gómez1, , Santiago J.A. Figueroa2, Diego G. Lamas3, Julio C. Cezar2

1Universidad de Guadalajara, Centro Universitario de Los Valles, Carr. Guadalajara-Ameca km 45.5, CP 46600, Ameca, Jal., México

2Brazilian Synchrotron Light Laboratory (LNLS) / Brazilian Center of Energy and Materials (CNPEM), CP6192, 13083-970, Campinas, SP, Brazil

3CONICET - Escuela de Ciencia y Tecnología, Universidad Nacional de Gral. San Martín, San Martín, Pcia. de Buenos Aires, Argentina

1. Supplementary information for the ≫XANES≪ section

Experimental data is provided as separate files: Attached the reader will find some examples of experimental XANES data. Files are explicitly named PVO_[Temperature]_[1/2] and each measure has a V foil in between I1 and I2. Therefore, we also include a measurement file of the V foil in the same position of the sample in the file named foil_4.

Error: Reference source not found shows the XANES spectra of the samples. The huge pre-peak for these V compounds is a characteristic of the forbidden transition 1s-3d [Wong et al]. There is a very close similitude in the shape of the spectra with a little difference with respect to the non cristalized sample PVO_120.

2. Supplementary information for the ≫Qualitative morphological description≪ section

As it was mentioned in the main text, Error: Reference source not found shows some low quality micrographs of the samples under study and, more specifically, Error: Reference source not found(a) and (b)

correspond to the single phase heat-treated powders at 500 °C and 600 °C while Error: Reference source notfound(c) and (d) correspond to our multiphasic samples, 750 °C and 800 °C. Both images, (a) and (b), reveal a noticeable submicrometric granular structure that, especially for T = 500 °C, features some clear monoclinic facets and very regular spatial distribution and morphology. However, the same could be said of samples treated at 750 °C and 800 °C but, as we have already seen and pointed out, the undesired crystalline quality for both specimens should prevent us from heating beyond 740 °C.