  The proposed new Electron-Ion Collider poses a technical and intellectual
challenge for the detector design to accommodate the long-term diverse physics
goals envisaged by the program. This requires a 4{\pi} detector system capable
of reconstructing the energy and momentum of final state particles with high
precision. The Electron-Ion Collider also requires identification of particles
of different masses over a wide momentum range. A diverse spectrum of Particle
Identification detectors has been proposed. Of the four types of detectors for
hadron identification, three are based on Ring Imaging Cherenkov Counter
technologies, and one is realized by the Time of Flight method. The quest for a
novel photocathode, sensitive in the far vacuum ultra violet wavelength range
and more robust than cesium iodide, motivated an R&D programme to explore
nano-diamond (ND) based photocathodes, started by a collaboration between INFN
and CNR Bari and INFN Trieste. Systematic measurements of the photo emission in
different Ar-CH4 and Ar-CO2 gas mixtures with various types of ND powders and
Hydrogenated ND (H-ND) powders are reported. A first study of the response of
THGEMs coated with different photocathode materials is presented. The progress
of this R&D programme and the results obtained so far by these exploratory
studies are described.
