Nobel metal Pt composites show high catalytic activity for hydrogen evolution reaction (HER) but limited in application by high Pt contents and therefore the cost. Herein, a series of Pt nanoparticle (NP)-deposited 2D Ti 3 C 2 T x MXenes were prepared by an atomic layer deposition (ALD) method with relatively low Pt contents (0.98−3.10 wt %) and showed excellent HER catalytic activity and stability. The electrochemical results indicated that the prepared catalysts showed the optimal HER activity as the ALD deposition cycle reached 40, with an overpotential of 67.8 mV approaching that of the commercial Pt/C catalyst (64.2 mV). The excellent behavior was attributed to the homogeneous dispersion of the Pt NPs and the good conductivity of the 2D Ti 3 C 2 T x MXene supports.

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We report that 2D crystals, prepared by delamination of layered terbium hydroxide (LTbH) intercalated with dodecyl sulfate ions (DS–) in formamide, can be modified by DS– ions and further restacked to a new layer‐structured compound. The modification proceeds in situ in formamide through the substitution of DS– for the hydroxyl groups, which coordinate to Tb3+ upon the delamination of the LTbH layer. With the supplementary addition of DS–, the substitution reaction progresses to a large degree of substitution, m > 2 in the chemical formula Tb2(OH)6–mDSm·nH2O. Since the negatively charged SO42– heads of DS– anchor to Tb3+, the alkyl chains protruding outwards convert the 2D crystal from hydrophilic to hydrophobic. The modified 2D crystals aggregate in aqueous media, restacking to the layered rare‐earth compound characteristic of m greater than 2. The restacked crystals are ready to delaminate in some organic solvents owning to their structural and hydrophobic features.

Eight kinds of (hetero)aromatic anions terminated with −COO − were intercalated into the interlayer of layered europium hydroxides (LEuHs) as sensitizers for enhancing Eu 3+ photoluminescence (PL) via an ion exchange with NO 3 − . Orientations of the anions in the interlayer were found to be vertical, tilted, or horizontal relative to the LEuH layer. The −COO − group was directly bonded to Eu 3+ in the mono-or didentate coordination in the vertical and tilted cases, whereas no direct coordination of anions was observed in the horizontal orientation. There are two distinctive factors that determine the orientation of these anions in the interlayer. First, the −COO − group is anchored to the positively charged layer through the electrostatic interaction. For this reason, the orientation of 1,3,5-benzenetricarboxylic acid (BTA) could be vertical as it was deprotonated to BTA 2− while horizontal as it was deprotonated to BTA 3− . The second important aspect is the key role of the weak interactions between the heteroatoms of the rings and OH − /Eu 3+ of the LEuH layer, including mainly hydrogen bonds, ionogenic-characterized interactions, and salt bridges. The stronger interactions resulted in more tilted guests. The hydrogen bonds between N−H in pyrrole-2-carboxylic acid and OH − of the layer were strong enough to make the guest horizontally orientating. The organic anion-intercalated LEuHs with vertical and tilted sensitizers showed enhanced PL intensity because of the energy transition effect by the intercalated sensitizers with respect to that of the LEuHs with horizontally oriented sensitizers.

We present a critical review of CNOs regarding the structure and synthesis process, elaborating the recent reports on soft-chemistry methods under mild conditions. In particular, solubility and interlayer spacing are discussed.

We report an environmentally friendly strategy for the synthesis of Fe3C/Fe/graphitic carbon based on hydrothermal carbonization and graphitization of carbon spheres with potassium ferrate (K2FeO4) at 800 °C.

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