Defect-Free Few-Layer M₄ C₃ T_x (M = V, Nb, Ta) MXene Nanosheets: Synthesis, Characterization, and Physicochemical Properties.

ABSTRACT: High-quality few-layer M₄ C₃ T_x (M = V, Nb, Ta) MXenes are very important for applications and are necessary for clarifying their physicochemical properties. However, the difficulty in etching for themselves and the existence of MC/MC_1-δ and M-Al alloy impurities in their M₄ AlC₃ precursors seriously hinder the achievement of defect-free few-layer M₄ C₃ T_x (M = V, Nb, Ta) MXenes nanosheets. Herein, three different defect-free few-layer M₄ C₃ T_x (M = V, Nb, Ta) nanosheets are obtained by using a universal synthesis strategy of calcination, selective etching, intercalation, and exfoliation. Comprehensive characterizations confirm their defect-free few-layer structure feature, large interlayer spacing (1.702-1.955 nm), types of functional groups (-OH, -F, -O), and abundant valance states (M⁵⁺ , M⁴⁺ , M³⁺ , M²⁺ , M⁰ ). M₄ C₃ T_x (M = V, Nb, Ta) free-standing films obtained by vacuum filtration of few-layer M₄ C₃ T_x inks show good hydrophilia, high thermostability, and conductivity. A roadmap on synthesis of defect-free few-layer M₄ C₃ T_x (M = V, Nb, Ta) nanosheets are proposed and three key points are summarized. This work provides detailed guidelines for the synthesis of other defect-free few-layer MXenes nanosheets, but also will stimulate extensive functional explorations for M₄ C₃ T_x (M = V, Nb, Ta) MXenes nanosheets in the future.

SUBMITTER: Huang Y 

PROVIDER: S-EPMC10558640 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature