Self‐Assembly of Biocompatible FeSe Hollow Nanostructures and 2D CuFeSe Nanosheets with One‐ and Two‐Photon Luminescence Properties

Abstract Transition metal chalcogenides are investigated for catalyst, intermediary agency, and particular optical properties because of their distinguished electron‐vacancy‐transfer (EVT) process toward different applications. In this work, one convenient approach for making pure‐phased FeSe nanocrystals (NCs) and doped CuFeSe nanosheets (NSs) through a wet chemistry method in mixed solvents is illustrated. The surface modification of each product is realized by using a peptide molecule glutathione (GSH), in which the thiol group (−SH) is ascribed to be the in situ reducer and bonding agency between the crystalline surface and surfactant in whole constructing processes. Due to the functional groups in biological GSH, highly aggregated NCs are rebuilt in the form of an FeSe hollow structure through amino and carboxyl cross‐linking functions through a spontaneous assembly procedure. Owing to the coupling procedure of Cu and Fe in the growth process, it generates enhanced EVT. Additionally, it shows the emission spectra of λ_EM‐PL = 436 nm (FeSe) and 452 nm (CuFeSe) while λ_EX‐PL = 356 nm, it also conveys two‐photon phenomenon while λ_EX‐PL = 720 nm. Moreover, it also shows strong off‐resonant luminescence due to two‐photon absorption, which should be valuable for biological applications.