Fabrication of cellulose@Mg(OH)2 composite filter via interfacial bonding and its trapping effect for heavy metal ions

Cellulose@Mg(OH) 2 was prepared via a facile method, which has both good shaping ability and high removal capability. The composite can be made into filter to remove heavy metal ion, and the treated water meets the potable water criteria. • Water treatment agent cellulose@Mg(OH) 2 was prepared via a facile method. • Cellulose guides to form ultrathin Mg(OH) 2 by non Van der Waals interaction. • Easy shaping property of our material makes HMIs’ separation practical. • High removal capacity and durability are achieved for HMIs’ removal. • Recovered HMIs can be retained on composite fibers and separated from water. The utilization of renewable biomass cellulose in treating pollution of heavy metal ions (HMIs) is one of overarching and appealing strategies, because it simultaneously satisfies sustainable development and resolves ever-increasing environmental issue. In this regard, the composite cellulose@Mg(OH) 2 was prepared via a facile method and explored for its use as water treatment agent. It is demonstrated that the smaller and thinner hexagonal Mg(OH) 2 flakes are constructed onto the cellulose substrate by self-assembling; two components are chemically coupled via hydrogen bonds and Mg-O c (cellulose oxygen) dative bonds; what’s more, the coupling of cellulose with Mg(OH) 2 (1 0 1) facet is much more preferential than with (0 0 1) facet. The resultant composite material shows remarkable HMI removal performance: large capacities of 734.9, 595.8 and 1473.1 mg g −1 for Cd 2+ , Cu 2+ and Pb 2+ , respectively. Further assisted by good shaping property of the cellulose substrate, the composite is capable of being made into filter, which practically separates HMIs and purifies wastewater with high removal efficiency (99.99%) for Cd 2+ even after operating for 110 days and potable water can be obtained. The mechanism is delineated with removal models and characterizations of HMI-recovered products.