Exceptional arsenic removal using novel mesoporous Mg-Al-Ti ternary composite oxide nanoparticles prepared via self-assembly templating method

Abstract

Arsenic contamination of water through natural and anthropogenic activities is a grave problem today. One of the most efficient ways to remove arsenic from water is through adsorption. Porous nanomaterials show high adsorption capacities due to high surface area, and efficient mass transfer with plenty of active adsorption sites. Porous metal oxides have been successfully employed to remove arsenic from water previously. However, ternary metal oxide composites hold potential for novel adsorbent materials but have yet to be explored in depth. Mesoporous Mg-Al-Ti oxide composite oxide nanoparticles with varying compositions were synthesized via a low-cost, scalable, evaporation-induced self-assembly technique using P123 block copolymer as a soft template. All the compositions of synthesized ternary oxide nanoparticles exhibited exceptionally high arsenic adsorption capacities ranging from 543 to 1215 mg/g for As(V) and 359.6–919.4 mg/g for As(III) along with 96–98% removal of arsenic from real groundwater samples of up to 489.3 ppb. The composites show mesopores and high surface area ranging from 93-393.6 m2/g with very small particle size ranging from 8 to 12 nm. The nanoparticles have shown great selectivity towards arsenic and exceptional adsorption performance in a wide pH range. High volume-to-surface area ratio, an abundance of hydroxyl groups, interconnected mesoporous morphology, and high point of zero charge pH contribute to the high adsorption capacity of the composite oxides. Mesoporous Mg-Al-Ti ternary oxide composite nanoparticles have shown higher adsorption capacity towards arsenic than many existing adsorbent material materials and can be a very promising candidate for arsenic remediation from water.