Synthetic Mechanism Studies of Iron Selenides: An Emerging Class of Materials for Electrocatalysis

Solution-processed iron selenide nanocrystals (NCs) have recently attracted considerable attention in electrocatalysis water splitting. Nevertheless, a primary challenge current iron-based NCs chemical synthesis is controlling phase purities between each chalcogen (monochalcogenide, dichalcogenides, and oxides), which requires comprehensive understanding of the reaction mechanisms at early stages nucleation. Herein, we investigate fundamental steps transforming molecular organoiron organoselenium precursors to selenides with view developing universal protocols for pure metal selenium oxides NCs. The main intermediate species volatile by-products are identified by high-resolution electron microscopy Nuclear Magnetic Resonance (NMR) spectroscopy (1H, 13C, 31P). Experimental evidence suggests that determining factor coordinating reactivity difference olefins (1-octadecene, oleylamine), tributylphosphine trioctylphosphine associated their corresponding Se bond cleavage. This work proposes interconversion during synthesis, offering synthetic strategy other electrocatalytically or photocatalytically active layered materials.