Fig. 7
From: Improving oxidation stability of 2D MXenes: synthesis, storage media, and conditions
a Illustration for the edge capping of MXene sheets with polyanions. The middle flake represents a typical as-synthesized fresh MXene flake. The top flake shows that the edge-capping of MXene with polyanions protect it from oxidation, while the bottom bare flake undergoes oxidation over prolonged exposure to water and air. b XRD patterns of 0.1 M polyphosphate-Ti3C2Tx (blue), 0.1 M polysilicate-Ti3C2Tx (green), 0.1 M polyborate-Ti3C2Tx (red), and untreated Ti3C2Tx (black), c XRD patterns of 0.1 M polyphosphate-V2CTx (black), and untreated-V2CTx (red) samples. Patterns are shifted vertically for clarity. Inset shows digital photographs of (i) 0.1 M polyphosphate-V2CTx (left) sample and (ii) untreated V2CTx sample (right) after three weeks of exposure to ambient air. Peaks of rutile are marked by asterisks. Typical SEM images of d untreated Ti3C2Tx and e 0.1 M polyphosphate-Ti3C2Tx samples. Typical TEM images of f untreated Ti3C2Tx and g 0.1 M polyphosphate-Ti3C2Tx samples. a-g Reproduced with permissions from ref. [59]. Copyright (2019), Wiley–VCH