Platinum Selenide Nanoparticle Synthesis and Reaction with Butyllithium Breaking the Long-Range Ordering Structure

PtSe2 is a transition metal dichalcogenide (TMD) material with a broad range of applications, such as sensors, electronics, and catalysis. Although 2D monolayers of PtSe2 have been widely studied, the synthesis of controlled PtSe2 nanoparticles (NPs) is still unexplored. Here, the new strategy to synthesize PtSe2 NPs was to react Pt NPs with selenium in a liquid state inside a homemade closed reactor. Afterward, the PtSe2 NPs reaction with butyllithium led to cleavage of the covalent bond along the ab-plane of 2D material (intralayer) and broke the PtSe2 long-range structure. The result was a PtSex nanomaterial with a greater concentration of defects having only the short-range ordering but keeping the local structure, as proved by Raman and ePDF analyses. X-ray photoelectron spectroscopy revealed a higher contribution from defects (Pt 4f ∼72 eV) for PtSex compared to the crystalline PtSe2 chemical environment (∼73.2 eV), probably due to the creation of edges on the surface of PtSex. PtSe2, and PtSex NPs’ performance toward the hydrogen evolution reaction (HER) application was tested, which indicated a better efficiency than bulk PtSe2. However, the disordered PtSex sample has better electrocatalytic activity, as the number of defects and increased edge exposure create more active sites. Therefore, the results reported here indicate that PtSe2 NPs can be produced using a fast and simple method compared to standard selenization processes, and the activation toward the HER was further enhanced by defect engineering.