Highly effective decontamination of lead is a primary challenge for ecosystem protection and public health. Herein, we report a methodology of ternary cations intercalation to synthesize Ti 3 C 2 T x MXene by structural control with angstrom-level precision through mixed fluorinated salts wet etching-alkalization approach for high-efficient lead adsorption. The successive introduction of lithium, potassium, and sodium ions continuously weakens interaction forces between Ti 3 C 2 T x layers, resulting in achieving fine tailored interlayer distance from 9.8 to 15.9 Å. A high density of complexing groups are formed after ternary cations intercalation, which greatly improve the hydrophilicity of Ti 3 C 2 T x to enhance the accessibility and shorten the mass transfer and provide abundant adsorption sites to exhibit strong complexing effects with lead ions. The prepared ternary cations-intercalated Ti 3 C 2 T x nanosheets exhibited a high adsorption capacity (267.2 mg/g) toward lead ions and sharply cut down lead concentration from 10 to 0.009 mg/L, far below the drinking water standards (0.015 mg/L).
Liu Liangbin,Tang Chongyang,Bu Lingzheng,Xiao Xiangheng,Huang Xiaoqing
Two-dimensional (2D) platinum (Pt)-based nanomaterials are considered as the ideal fuel cell catalysts, while their rational synthesis associated with phase control remains a formidable challenge. Herein, we firstly design the novel 2D Pt-lead-sulphur heterophased nanosheets (PtPbS HPNSs) as efficient high-toleration electrocatalysts for methanol oxidation reaction (MOR). They exhibit much higher activity and more highlighted bifunctional antipoisoning abilities than PtPb NSs and commercial Pt/C. Further density functional theory (DFT) simulation verifies that the decreased electron density of Pt sites worked by Pb and S makes CO intermediate favorable to desorb, avoiding the formation of CO*-polluted Pt sites. Simultaneously, this heterophased interface effectively weakens the adsorption of S 2− -species and improves the S-poisoning tolerance, showing a route to realize nearly innoxious catalysis. The present work highlights the importance of heterophase control in tuning antipoisoning property for 2D Pt-based nanomaterials, which is key for the rational design of efficient fuel cell anodic catalysts.