Dr. Mario Santoro

Title: Recent achievements in the synthesis of carbon nano-threads and in the hydrogen insertion in zeolites

Language: English presentation

Time: 2024/06/13 10:00-11:00

Place:  Conference room 410, HPSTAR (shanghai)

             Online:  Tencent Meeting:  https://meeting.tencent.com/dm/e6QEf1PXVyss

Meeting ID:  597-487-340

Host:  Dr. Federico Gorelli

ABSTRACT:

The content of the seminary will be twofold. In the first part, I will present novel carbon nano-threads obtained at high pressures. Indeed, the synthesis of hydrogenated carbon nanothreads at tens of GPa from aromatic systems is one of the most brilliant recent findings in high-pressure science. C-nanothreads combine the high tensile strength of diamond with the high flexibility of polymers, and many efforts are currently being undertaken to tailor some useful physicochemical properties by smartly modifying their local structure. I will present the synthesis of double core diamond-like nanothreads with the two cores being bound by a conjugated C, polyacetylene-like backbone. The two cores also form a protecting sheath for the backbone. This material exhibits an optical bandgap of 1.74 eV, similar to polyacetyelene; it is then very attractive as a potential organic semiconductor with simultaneous outstanding mechanical properties. The synthesis was achieved by reacting diphenylacetylene in diamond anvil cells, at 25−30 GPa and room temperature, and the materials were characterized by optical spectroscopy, synchrotron X-ray diffraction, and ab initio computer simulations. I will also show the synthesis of millimeter-sized samples of these new materials, achieved in a large volume, multi-anvil two-stage press. In the second part of the seminary, I will show how hydrogen can be, in principle, efficiently stored in micro-porous materials such as the zeolites. Indeed, we found that molecular hydrogen, used as the pressure transmitting medium, very efficiently fills and ultimately saturates the 1D pore systems of siliceous zeolites at high pressure, based on x-ray diffraction, Raman spectroscopy and Monte Carlo simulations. More importantly, we observed that zeolites of this type, when compressed in H2, undergo first-order phase transitions in the GPa regime, with volume jumps of up to 22%, which in turn are driven by the hydrogen uptake that discontinuously increases from 0.5-0.8 H2/SiO2 unit to 1.5-1.7 H2/SiO2 unit.

BIBLIOMETRIC PARAMETERS:

-PAPERS (ISI WEB OF SCIENCE AND SCOPUS): 125

-H-INDEX (ISI WEB OF SCIENCE AND SCOPUS): 34

EDUCATION AND APPOINTMENTS

1994 Graduated in Physics, Univ. of Florence.

1994-1997 Ph. D. in Solid State Physics, Univ. of Florence.

1998-2000 Post-doc Fellowship at LENS, Florence, Italy.

2000-2011 Research Scientist, LENS.

2011-2019 Researcher, IFAC-CNR and then INO-CNR.

2019 (Nov)-2019 (Dec) Senior Researcher, INO-CNR.

2020 (Jan)-Today Research Director, INO-CNR.

VISITED LABORATORIES (High Pressure Physics)

- June-July 2021, visiting scientist, ICGM of Montpellier, France.

- April-May 2019, Invited Professor, ISSP of Hefei, CAS, China, awarded by the CAS President’s International Fellowship Initiative (PIFI).

- April 2017, Invited Professor, ISSP of Hefei, CAS, China.

- Sept.-Oct. 2013, Invited Professor, ICGM, France.

- Sept.-Oct. 2011, Invited Professor, Univ. of Nîmes, France.

- Sept.-Oct. 2010, Invited Professor, Univ. of Nîmes, France.

- Sept.-Oct. 2009, Invited Professor, Univ. of Montpellier II, France.

- June 2003-July 2004, Post-Doc Associate, Geophysical Lab. of the Carnegie Inst. of Washington, U.S.A.

- June 2001, visiting sci., CNRS-LPCM, Meudon, France.

- Since 2000, user of synchrotron and neutron facilities. Granted beam times: 71.