Low Carbonate Contaminative and Ultrasmall NiAl LDH Prepared by Acid Salt Treatment with High Adsorption Capacity of Methyl Orange

Abstract

Layered double hydroxides (LDHs) are attracting intense research interests as methyl orange (MO) adsorbent due to the unique anionic exchange ability. Herein, ultrasmall NiAl LDHs with Cl– intercalation were prepared by a facile method combining hydrothermal method with acid salt treatment. As a result, the as-prepared NiAl LDHs displayed favorable removal performance toward MO from aqueous solution due to the negligible carbonate contamination and ultrasmall nanosheets (about 50 nm). The maximum experimental and theoretical adsorption capacities of 853.19 and 900.14 mg g–1 at pH = 7 and T = 298 K for MO were achieved for Ni4Al1–Cl LDH. The adsorption mechanism is dominated by chemisorption, and the adsorption process is spontaneous and endothermic. Possible “intercalation-split mechanism” for MO on NiAl–Cl LDH is proposed to explain the split of (003) plane. The improvement of adsorption capacity indicates that the acid salt treatment is an effective strategy to construct the rapid and high-effective anionic dyes adsorbents.

Chemical Modifications of Layered Double Hydroxides in the Supercapacitor

“…However, from the perspective of intercalation thermodynamics, the high affinity between CO 3 2− and the host layer of LDHs has a negative effect on the intercalation of OH − . [ 60 ] Hence, we hope to obtain LDHs with the intercalation of other anions by simple and operable methods and then enhance the interaction between the LDHs and the OH − . Some other anions such as OH − , NO 3 − , SO 4 2− , and Cl − are promising candidate anions and have been widely researched.…”

Synergetic Engineering of High‐Oxidation‐State Cations on Phase Boundaries toward High‐Efficiency Water Splitting

“…In the Ni 2p spectrum of Fe‐o‐NiAlOH, the binding energies (BEs) at 856.0 eV and 857.1 eV put down to Ni 2p 3/2 of Ni 2+ and Ni 3+ , respectively, and the high BEs at 873.7 eV and 874.7 eV put down to Ni 2p 1/2 of Ni 2+ and Ni 3+ , respectively, implying the coexistence of Ni 2+ and Ni 3+ in Fe‐o‐NiAlOH (Figure 3b) [40,48,49] . The Al 2p spectrum of Fe‐o‐NiAlOH (Figure 3c) exhibits a typical peak at 74.1 eV, confirming the trivalent oxidation state of Al in Fe‐o‐NiAlOH [50] . Ni 3p at 67.9 eV is also visible in the Al region (Figure 3c) [51–53] .…”

Single-Step Topochemical Synthesis of NiFe Layered Double Hydroxides for Superior Anion Removal from Aquatic Systems

“…The effect of the Cl – ion intercalation method on the adsorption capacity was investigated. Conventionally, Cl – ion intercalation has been successfully achieved by using a mixture with a high concentration of NaCl (4.00 M) and HCl (0.033 M). − The fabrication protocols are described in the Supporting Information. In our case, the facile procedure was introduced by using only HCl (0.33 M).…”

“…Most synthesized LDH adsorbents contain carbonate (CO 3 2– ) ions in the interlayer because they can easily capture carbon dioxide gas from the environment during preparation. It is difficult to achieve anion exchangeability because of the strong affinity between CO 3 2– ions and the metal host layer, resulting in a low adsorption capacity. , Consequently, an effective technique for preparing LDH adsorbents and modifying the interlayer is required to enhance the adsorption performance.…”