Anchoring H3PW12O40 on aminopropylsilanized spinel‐type cobalt oxide (Co3O4‐SiPrNH2/H3PW12O40): A novel nanohybrid adsorbent for removing cationic organic dye pollutants from aqueous solutions

Abstract

In this work, phosphotungstic acid (H3PW12O40; PW12) was chemically anchored on aminopropylsiloxane functionalized spherical Co3O4 nanoparticles (Co3O4–SiPrNH2) and the resultant nanocomposite (Co3O4–SiPrNH2/PW12) was fully characterized. The results demonstrated successful anchoring of PW12 on the surface of Co3O4–SiPrNH2nanoparticles. The Co3O4–SiPrNH2/PW12 nanohybrid indicated a specific surface area of 42.14 m2 g−1, which was greater than that of pure PW12 (ca. 5 m2 g−1). The adsorption efficiency of this novel adsorbent nanomaterial was evaluated for removing methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) dyes from aqueous solutions. The hybrid nanomaterial exhibited a high adsorption rate and selective adsorptivity for the cationic MB and RhB dyes compared to those for anionic MO dye. The prepared hybrid nanomaterial removed over 98% of MB within 12 min. The effects of initial pH, contact time, adsorbent dosage, and temperature were investigated on the adsorption process. The adsorption capacity of nanohybrid for cationic MB dye was 38.46 mg g‐1. Also, adsorption kinetics indicated that the adsorption by Co3O4–SiPrNH2/PW12 was well‐modeled using pseudo‐second‐order kinetic model. Finally, thermodynamic parameters revealed that the adsorption was endothermic and spontaneous. The adsorption rate and ability of the Co3O4–SiPrNH2/PW12 were enhanced as compared with Co3O4 and Co3O4–SiPrNH2 samples due to enhanced electrostatic attraction intraction. The nanohybride was easily separated and reused without any change in structure. Thus, it could be a promising green adsorbent for removing organic pollutants in water.