April
Picture of the Month - April 2022
The liquid-phase exfoliation of molybdenum trioxide for the production of 2D nanosheets colloidal inks
The interest in layered 2D nanomaterials has witnessed an impressive growth in the last years, bringing to the discovery of many new species and methods for their preparation. The liquid-phase exfoliation (LPE) of crystalline bulk powders is certainly the most suitable method for scaled-up production, allowing also the convenient access to solution processing techniques for the direct utilization of the produced 2D material colloidal inks. Given the large number of reports on LPE processes for different 2D materials, today, it is necessary to specifically define the results of similar investigations, so as to provide the scientific community with clear guidelines for identifying design rules and applying standardized procedures.
In our work, we describe a systematic study on the LPE process for α-MoO3, a stable high band gap semiconductor, which in its 2D form has been employed for many purposes, ranging from catalysis to energy/optoelectronic devices and sensing. We investigate the effect of different low-toxicity solvents and instruments for its LPE and provide new insights into the structural and electronic properties of the resulting 2D nano-inks in a joint experimental–computational effort, which will represent a solid source of information for the future implementation of liquid-dispersed layered α-MoO3 nanosheets in different fields. In particular, we resorted to X-ray absorption spectroscopy (XAS), carried out at the Synchrotron Soleil facilities in France, to probe the atomic distances in the bulk and LPE materials, evidencing the occurrence of a strain in the latter which was never described before. For this work, we collaborated with Prof. Silvia Gross and Prof. Stefano Agnoli from the University of Padua (Italy) and with Dr. Silvio Osella from the University of Warsaw (Poland).
A related publication can be found at https://doi.org/10.1021/acs.jpcc.1c09221
This picture was submitted by Dr. Teresa Gatti.
Further insights into the research activities of the ZfM groups can be found in the Gallery.