Chemical Exfoliation for the Preparation of CrSe₂ Nanoribbons and CrTe2–x Nanosheets

Recently, there has been interest in developing stable dispersions of freestanding, low-dimensional crystalline materials. These dispersions can be converted to inks, which in turn can be printed on substrates and used for a variety of applications. Chemical exfoliation has been a promising method for the acquisition of these inks. Here, we introduce the use of chemical exfoliation for preparing two freestanding transition metal dichalcogenides dispersions: CrSe2 nanoribbons and CrTe2–x (x ≈ 0.2) nanosheets. The former was exfoliated from KCrSe2 in dilute acetic acid in isopropyl alcohol, whereas the latter was exfoliated from LiCrTe2 in water. We explore the exfoliation of KCrSe2 at various intervals throughout the process to better understand what led to the formation of nanoribbons instead of nanosheets. Meanwhile, we show that the chemically exfoliated CrTe2–x has room-temperature ferromagnetism, as evidenced by magnetization data. The different products of chemical exfoliation processes presented here, ranging from freestanding nanoribbons and sheets to processable ink that is ferromagnetic at room temperature, emphasize the versatility of chemical exfoliation and their potential in future applications.