Mesoporous zinc silicate composites derived from iron ore tailings for highly efficient dye removal: Structure and morphology evolution.

In recent years, using waste iron ore tailings (IOT) as a starting material to synthesize new materials has become an emerging hot topic, but the remaining challenge is the lack of effective ways to maximize the use of each component in the IOT. In this work, two novel materials including the mesoporous zincsilite composite assembled by a layered structure with flower-like morphology and the willemite composite composed of ellipsoidal particles were synthesized from high-silicon IOT via a facile one-step hydrothermal reaction process. Due to the transformation from IOT to zincsilite composite, typical mesoporous structure was formed and the specific surface area was increased by 75.1 m2 g−1. The transformation mechanisms from IOT to zinc silicate composites were proposed based on the study of the synthesis process. The zincsilite composite shows fast adsorption rate and high adsorption capacity for MB, which is mainly attributed to the emerging mesopores and special layered structure. Specifically, the removal efficiency for methylene blue exceeds 97% within 10 min, and the maximum adsorption capacity reaches up to 180.5 mg g−1, which is over 9 times higher than that of raw IOT. Furthermore, analysis of adsorption mechanism demonstrated that the adsorption process was mainly caused by the synergistic effect of both hydrogen bonding and electrostatic attraction. The excellent adsorption property endows the composite with potential application in the field of dye wastewater treatment. Image 1 • A facile functional utilization strategy of iron ore tailings (IOT) was proposed. • Mesoporous zinc silicate composite was prepared by one-step hydrothermal reaction. • IOT as an industrial waste was used as a low-cost silicon source in the preparation. • The structure and morphology evolution of zinc silicate composite was explored. • Zincsilite composite showed fast rate and high capacity for adsorption of dye. [ABSTRACT FROM AUTHOR]