Sea Sand as a Silica Source to Hydrothermally Synthesize Analcime

Materials (Basel). 2025 Jun 16;18(12):2818. doi: 10.3390/ma18122818.

Abstract

Analcime has demonstrated potential for a variety of applications in technology, especially in adsorption and heterogeneous catalysis. In this study, synthetic analcime was investigated by using sea sand as a silica source. Sea sand was first treated with HNO3 and NaOH. The pretreated sea sand as the silica resource and Al(NO3)3 as the aluminum source were used for the hydrothermal synthesis of analcime with different ratios of Si/Al and Na/Si. The products obtained under different conditions were characterized by X-ray diffraction. The results showed that analcime synthesized using acid-treated sea sand was mixed with other impurities, such as quartz and sodalite. Pure analcime was obtained using alkali-treated sea sand as the silica source. The analcime prepared under an optimized synthesis condition was further investigated via SEM, FT-IR, and TG. The particle size of the prepared analcime ranged from 40 to 50 μm. The adsorption ability of analcime was studied, and the Cu2+ adsorption process was found to follow a pseudo-second-order kinetic model.

Keywords: Cu2+ adsorption; hydrothermal synthesis; sea sand; synthetic analcime.