Largely enhanced adsorption performance and stability of MXene through in-situ depositing polypyrrole nanoparticles

• MXene/PPy composite particles were successfully prepared. • The composite particles showed high adsorption capacity toward MB. • The stability of MXene during the storage process was enhanced. Due to the high presence of active functional groups, two-dimensional transition metal carbide/nitride materials that are usually named MXene have been thought as an efficient adsorbent for the removal of organic contaminants from wastewater. However, the poor stability of MXene originated from the high oxidization performance greatly restricts their application. In this work, few-layered MXene was firstly prepared and then the in-situ polymerization of polypyrrole (PPy) was induced in the MXene solution to prepare the MXene/PPy composite particles. The microstructure, adsorption behaviors toward methylene blue (MB) and the stability during the storage process were systematically investigated. The results show that introducing PPy nanoparticles promotes the further exfoliation of MXene. Consequently, the adsorption ability of the MXene/PPy composite particles is significantly enhanced, and the maximum adsorption capacity reaches 553.57 mg/g. The MXene/PPy composite particles also show high adsorption selectivity and it can exclusively remove MB from the solution mixing both cationic and anionic dyes simultaneously. The stability of the MXene is greatly enhanced and nearly no oxidization is observed for the MXene/PPy composite particles. This study offers an additional way to fabricate the MXene-based adsorbents with high stability, and the composite particles exhibit promising applications in effluent water remediation.