Bismuthene@ZnAlBi LDHs structure as a novel nanosorbent for efficient uptake of arsenic (V)

Abstract

AbstractTwo-dimensional bismuthene material is characterized with promising and superior optical, electrical and other characteristics. The application of 2D-bismuthene or its composites in water remediation of As(V) was not previously investigated. Consequently, embedded bismuthene into zinc aluminum bismuth-layered double hydroxide (ZnAlBi LDHs-embedded-Biene) was simply fabricated as a novel nanosorbent. Bismuthene (Biene) was prepared by bottom up hydrothermal reaction, while ZnAlBi LDHs was synthesized by a coprecipitation method followed by hydrothermal treatment process. Characterization of ZnAlBi LDHs-embedded-Biene referred to a crystalline mesoporous structure of globular particles with 5–8 nm. It was confirmed that the nanosorbent exterior surface is functionalized with metal oxides and metal oxyhydroxide, while exchangeable carbonate anion existed in the nanosorbent inner layer. Therefore, arsenate uptake was favored by both exterior electrostatic attraction and anion exchange processes. The highest uptake capacity of As(V) by ZnAlBi LDHs-embedded-Biene was detected at pH 3 and contact time 30 min providing 94.67% removal by using 5 mg L−1 As(V) concentration. The ionic strength factor proved a good selectivity of the nanosorbent toward As(V) ions. Thermodynamic behavior of interaction between As(V) and nanosorbent was emphasized as exothermic and spontaneous process, while the kinetic evaluation indicated that the pseudo-second order was the best-fitting expression. The application of ZnAlBi LDHs-embedded-Biene in the adsorptive uptake process of As(V) ions from various water samples referred to elevated uptake percentages as 93.29% and 90.52% by 5 mg L−1 and 10 mg L−1 As(V), respectively. The adsorbed As(V) onto ZnAlBi LDHs-embedded-Biene exhibited excellent recyclability and re-usage up to five cycles to affirm that the designed ZnAlBi LDHs-embedded-Biene has a great prospect for utilization in water purification from As(V).