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A simple redox method was used to synthesize δ-MnO2 and introduce the first main group metal elements between the layers of δ-MnO2. Through testing, we found that δ-MnO2 doped with Rb+ demonstrated the best catalytic performance for formaldehyde removal. Under the condition of 36 °C and the initial formaldehyde concentration of 200 ppm, a 200 mg of Rb-MnO2 could achieve the percentage of removal of formaldehyde 97.48%. We found that doping elements with low electronegativity and large ion radius could weaken the Mn–O bond, which is conducive to the formation of reactive oxygen species and improve the performance of catalytic oxidation. [ABSTRACT FROM AUTHOR]

A simple redox method was used to synthesize δ-MnO2 and introduce the first main group metal elements between the layers of δ-MnO2. Through testing, we found that δ-MnO2 doped with Rb+ demonstrated the best catalytic performance for formaldehyde removal. Under the condition of 36 °C and the initial formaldehyde concentration of 200 ppm, a 200 mg of Rb-MnO2 could achieve the percentage of removal of formaldehyde 97.48%. We found that doping elements with low electronegativity and large ion radius could weaken the Mn–O bond, which is conducive to the formation of reactive oxygen species and improve the performance of catalytic oxidation. [ABSTRACT FROM AUTHOR]

Layered materials are promising candidates to serve for thermal insulation coatings because of their low out‐of‐plane thermal conductivity. The thin film preparation of the layered materials in layer‐by‐layer fashion can be realized by several solution processes. However, the layered materials suffer low thermal stability after the solution processes. Herein, we report a strategy to improve the thermal stability of the layered materials processed in solution. In this work, we studied the thermal stability of the lepidocrocite‐type titanate with various interlayer ions (Li+, Na+, K+, and Cs+) at elevated temperatures. We proved that the thermal stability of the titanate increased with the increase of the ionic radius. The Cs+ intercalated titanate can remain in its layered structure up to 1000°C, while the Li+ interacted titanate loses its structural stability at ~280°C. Our work suggests that increasing the size of the interlayer ions is an effective strategy to enhance the structural stability of layered titanates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two-step preparation to obtain Co(OH) 2 with in situ intercalation of sulphate ions. • Sulphate ion intercalation modulates the band structure, light absorption, and electrical conduction of Co(OH) 2 to enhance photocatalytic/photo-electrocatalytic water splitting. • The α-Co(OH) 2 photoanode shows a photocurrent density of 4.36 mA·cm−2 at 1.23 V RHE. • Density functional theory calculations demonstrate the formation of Co active sites and the mechanism of water splitting. In this study, α-Co(OH) 2 with sulfate groups in interlayer was obtained through alkaline etching of cobalt hydroxide sulphate. The layered structure of α-Co(OH) 2 offers abundant adsorption sites and promotes efficient ion exchange. The introduction of sulfate ions induces changes in the electronic structure and interlayer spacing of α-Co(OH) 2 , resulting in heightened light absorption and electrical conductivity. Experimental results and density functional theory calculations demonstrate that α-Co(OH) 2 has outstanding photocatalytic hydrogen evolution and photoelectrocatalytic water splitting properties. In particular, the α-Co(OH) 2 photoanode shows a photocurrent density of 4.36 mA·cm−2 at 1.23 V RHE. This research not only provides an effective catalyst for photocatalytic and photoelectrocatalytic applications, but also provides insights into the underlying mechanism, which could inspire the development of materials with interlayer ions and have implications for a range of other applications. [ABSTRACT FROM AUTHOR]

Using molecular dynamics simulations, the interlayer swelling pressure of Na-montmorillonite clay was determined at different dry densities and ionic strengths while varying the concentration of NaCl and CaCl 2. The composition and charge of the interlayer ions in the clay were also analysed. When the salt composition of the surrounding environment is varied, its influence on the swelling pressure is dependent on the overall ionic strength and dry density of the clay. At low or moderate dry density, as the ionic strength percentage ratio of NaCl to CaCl 2 decreases, the swelling pressure trend shows a downward slope. In addition, at high dry density, the swelling pressure increases as the ionic strength percentage ratio of NaCl to CaCl 2 decreases. The composition and the total charge in the interlayer space of Na-montmorillonite clay are dependent on the ionic strength, ionic strength percentage ratio of the surrounding solution and d-spacing of the clay layers. [ABSTRACT FROM AUTHOR]

• A interstratification assembly hybrid electrode is prepared. • The MXene/NiCo-LDHs exhibits high capacitance of 1207 F g−1. • The maximum energy density of 107.3 Wh kg−1 at 571 W kg−1. • This is attributed to hydration and exchange or adsorption of interlayer anions-cations. The application of two-dimensional layered hybrid materials in supercapacitor electrodes has high energy density. However, the hybrid assembly and electrochemical energy storage mechanism of multifarious layered electrode materials are still unclear. In this work, a two-dimensional interstratification assembly hybrid electrode by using electrostatic assembly between MXene modified with cetyl trimethylammonium bromide cation (CTAB) and NiCo-LDHs modified with dodecyl benzene sulfonic acid anion (DBS) is presented. As a result, the self-restacking of MXene and NiCo-LDHs nanosheets are effectively prevented, leading to a regular interstratification structure and large interlayer spacing, which accelerate diffusion of electrolyte ions and possess more electrochemical activity sites. The freestanding MXene/NiCo-LDHs electrode displays a much higher specific capacitance of 1207 F g−1 at a scan rate of 0.5 A g−1, an impressive rate capability with 93% capacitance retention after 5000 cycles. Moreover, it shows maximum energy density of 107.3 Wh kg−1 (98.5 mWh cm−3) at a power density of 571 W kg−1 (524 mW cm−3), which is among the highest values reported for MXene and NiCo-LDHs based materials in aqueous electrolytes. This significant electrochemical performance is mainly attributed to hydration of two-dimensional electrodes and exchange or adsorption of interlayer anion-cation. [ABSTRACT FROM AUTHOR]