Thermal oxidation synthesis of MoS2/MoO3 composites for cationic dye adsorption†

Abstract

This study investigates the influence of synthesis parameters on the preparation of MoS₂/MoO₃ composites and their adsorption performance for methylene blue (MB) dye removal. The research gap is based on searching for easily obtainable materials with high adsorption capacity. A 2^k factorial design with a central point was employed to optimize the synthesis conditions, focusing on calcination temperature and time. The synthesized materials were characterized, revealing the MoS₂/MoO₃ composition at the calcination temperature of 300 °C, with varying calcination times. In particular, the sample treated at 300 °C for 23 minutes (S-300/23) demonstrated the highest maximum adsorption capacity, reaching 505.1 mg g⁻¹. The adsorption isotherm and kinetics were also evaluated, fitting with Langmuir and pseudo-first-order models, indicating monolayer adsorption and physisorption as the dominant mechanism, respectively. This study highlights the potential of MoS₂/MoO₃ composites as efficient adsorbents for MB dye removal. The optimized synthesis conditions enable the production of this composite adsorbent in a single step under mild conditions. This efficiency and ease of production highlight its potential for further investigation.