Self-Templated Synthesis of PPy@MoS2 Micro-/Nanotubes with Programmable Surface Properties for Removal of Cationic Dyes and Proteins

Abstract The precise co-tuning of morphology and surface charge in MoS2-based composites remains a critical challenge in designing high-performance adsorbents. Here, a tunable hydrothermal sulfidation strategy that enables the controllable synthesis of tubular PPy@MoS2 composites is presented. By systematically varying the hydrothermal synthesis temperature of the MoOx@PPy precursors (120–200 °C), precise modulation of the PPy@MoS2’s phase composition, morphology, porosity, and surface charge was achieved. Notably, the in situ-polymerized polypyrrole (PPy) layer acts as a structural stabilizer throughout the phase evolution and sulfidation processes, preserving the tubular architecture. The PPy@MoS2 synthesized from MoOx@PPy (120 °C) exhibited the most negative zeta potential, resulting in exceptional methylene blue adsorption capacity of 148.66 mg g–1. In contrast, the PPy@MoS2 derived from MoOx@PPy (200 °C) achieved the highest specific surface area with a well-developed meso-/macroporous hierarchy, enabling a superior lysozyme adsorption capacity of up to 63.77 mg g–1 dominated by van der Waals forces and hydrophobic interactions─where electrostatic effects were secondary. Both adsorption processes adhered to the Langmuir isotherm and pseudo-second-order kinetic model, confirming monolayer chemisorption as the rate-limiting mechanism. This work establishes a generalizable framework for engineering transition metal dichalcogenide-based adsorbents with programmable surface properties, offering targeted solutions for wastewater remediation and protein separation.