Sub‐nanometric particles (SNPs) of atomic cluster sizes have shown great promise in many fields such as full atom‐to‐atom utilization, but their precise production and stabilization at high mass loadings remain a great challenge. As a solution to overcome this challenge, a strategy allowing synthesis and preservation of SNPs at high mass loadings within multishell hollow metal–organic frameworks (MOFs) is demonstrated. First, alternating water‐decomposable and water‐stable MOFs are stacked in succession to build multilayer MOFs. Next, using controlled hydrogen bonding affinity, isolated water molecules are selectively sieved through the hydrophobic nanocages of water‐stable MOFs and transferred one by one to water‐decomposable MOFs. The transmission of water molecules via controlled hydrogen bonding affinity through the water‐stable MOF layers is a key step to realize SNPs from various types of alternating water‐decomposable and water‐stable layers. This process transforms multilayer MOFs into SNP‐embedded multishell hollow MOFs. Additionally, the multishell stabilizes SNPs by π‐backbonding allowing high conductivity to be achieved via the hopping mechanism, and hollow interspaces minimize transport resistance. These features, as demonstrated using SNP‐embedded multishell hollow MOFs with up to five shells, lead to high electrochemical performances including high volumetric capacities and low overpotentials in Li–O₂ batteries.

Layered double hydroxides (LDHs) are promising photocatalysts for water oxidation, essential to generate solar fuels, but their limited accessible reaction sites, slow charge transfer, and activity degradation are yet to be overcome. As a solution to overcome these drawbacks, we report nanosheets of mono or dual layers derived via nitrogen plasma exfoliation of anion layers from NiAl LDHs. Moreover, such a sheet has rich O vacancies resulting in decreased Ni–O and shortened Ni–metal bonds. Furthermore, doped nitrogen leads to metal–N and N–O bonds along with oxynitrides. With O vacancies facilitating adsorption of water oxidation intermediates onto low-coordinated Ni and the doped N pulling electrons from water oxidation intermediates, the ultrathin nanosheets assembled on hematite nanorods are found to outperform the activity of hematite by about 2 fold and the charge transfer of LDH nanoplates assembled on hematite by about 4 fold, while showing excellent activity retention close to 100% in a long-term stability test.

Supercapacitors are promising energy storage devices with high charging/discharging speeds and power densities. To improve their poor stability, we fabricated electrodes by integrating perovskite materials (La_0.8Sr_0.2Mn_0.5Co_0.5O_3-δ, LSMCO) possessing redox reaction ability with graphene nanoplatelets exhibiting good electronic properties. One of the resultant composites (L25G70) demonstrated high capacitance and excellent capacitance retention (95% after 5000 cycles). These results are superior to other electrodes (L50G45 and L75G20) containing a larger ratio of LSMCO, even L75G20 did not exhibit supercapacitor behavior after 3000 cycles. GN can induce structural distortion in LSMCO, thereby the high amount of adsorbed oxygen per lattice oxygen can explain the best electrochemical performance of L25G70, while structural collapse rationalized the failure of L75G20. The findings of this study demonstrated that the use of LSMCO can improve the cycling stability of supercapacitors.

Multimetallic electrocatalysts have shown great potential to improve electrocatalytic performance, but their deteriorations in activity and durability are yet to be overcome. Here, metal‐organic fragments with adhesive excipient to realize high activity with good durability in oxygen evolution reaction (OER) are developed. First, a leaf‐like zeolitic–imidazolate framework (ZIF‐L) is synthesized. Then, ionized species in hydrogen plasma attack preferentially the organic linkers of ZIF‐L to derive cobalt–imidazole fragments (CIFs) as adhesive excipient, while they are designed to retain the coordinated cobalt nodes. Moreover, the vacant coordination sites at cobalt nodes and the unbound nitrogen at organic linkers induce high porosity and conductivity. The CIFs serve to stably impregnate trimetallic FeNiMo electrocatalysts (CIF:FeNiMo), and CIF:FeNiMo containing Fe contents of 22% and hexavalent Mo contents show to enable high activity with low overpotentials (203 mV at 10 mA cm⁻² and 238 mV at 100 mA cm⁻²) in OER. The near O K‐edge extended X‐ray absorption fine structure proves further that high activity for OER originates from the partially filled e_g orbitals. Additionally, CIF:FeNiMo exhibit good durability, as demonstrated by high activity retention during at least 45 days in OER.