Haomin Jiang

Hollow multishelled structure (HoMS) integrates concentric shells, intershell voids and hierarchical interfaces into spatiotemporally ordered microenvironments that couple active-site exposure, mass transport and multistep reaction control. In this work, we compare sequential templating, hard- and soft-templating, template-free and emerging conversion routes, emphasizing control over shell number, spacing, composition, crystallinity and heterointerfaces. We then establish structure–performance relationships across the oxygen reduction, oxygen evolution and hydrogen evolution reactions as well as CO2 reduction, nitrate/nitric oxide reduction, alcohol oxidation and Li–S battery. Particular attention is given to confinement-enhanced reactant enrichment, directional transport, intershell electronic interactions and structural buffering, which collectively govern activity, selectivity and durability. Finally, we identify the key barriers to practical deployment: atomic-scale structural control, mechanistic resolution, scalable synthesis; we also outline design principles for translating HoMS from architecturally complex nanomaterials into efficient and robust electrocatalysts.

Ag/CoMoO ₄ electrocatalysts were successfully constructed, wherein the solid-state redox mediator properties of Ag/CoMoO ₄ heterostructures were activated and superior electrocatalytic activity was achieved via accelerated LiO _x conversion kinetics.

The precise determination of 5‐hydroxyindole acetic acid (5‐HIAA), an essential biomarker for neuroendocrine tumors and neurological diseases, is of paramount importance. Herein, we develop a sensitive electrochemical sensor based on an oxidized graphite felt (OGF) electrode, functionalized with oxygen‐containing groups via facile thermal oxidation. The synergistic integration of these moieties with the inherent 3D porous structure facilitates hydrogen‐bonding interactions, enabling efficient capture of a crucial oxidative intermediate of 5‐HIAA: its cationic free radical. This unique molecular recognition mechanism generates a distinctive six‐peak voltammetric signature in cyclic voltammetry, providing deeper insights into the complex oxidation pathway of 5‐HIAA. Utilizing adsorptive stripping square wave voltammetry, the OGF sensor achieves a wide linear range of 0.35–26.5 μmol/L and a low limit of detection of 0.094 μmol/L (S/N = 3). The enhanced analytical performance is directly linked to the superior intermediate‐trapping capability of OGF, highlighting its potential for reliable biosensing applications.

In Li-O₂ batteries, Li₂O₂ serves as the primary cathodic material but its wide band gap imparts insulating properties. Regulating the composition and morphology of Li₂O₂ enables the construction of a novel cathodic structure with exceptional electrochemical performance. Herein, we introduce an organic salt containing cobalt ions, cobalt acetylacetonate (Co(acac)₂), into the cathodic electrolyte. We exploit its cation migration characteristics under an electric field to facilitate the generation and decomposition of Co-doped Li₂O₂, achieving gradient control and optimized growth of Li₂O₂. Moreover, the Co(acac)₂ molecule stabilizes the properties of LiO_x species and mitigates side reaction. In situ UV-vis and XANES spectra reveal direct interactions between Co(acac)₂ and O₂^-/LiO₂, highlighting the superior reversibility of Co(acac)₂ enhanced Li-O₂ batteries. Both experimental and theoretical results indicate that this novel Li-O₂ battery system exhibits rapid reaction kinetics, with a reduced overpotential of 520 mV and extended cyclability, surpassing 400 cycles with lower polarization.

Iron-nitrogen-carbon (Fe-N-C) materials are recognized as an effective category of catalysts that do not contain platinum (Pt) for the oxygen reduction reaction (ORR). Nonetheless, the long-term stability and effectiveness of these materials are significantly hindered by the dissolution and oxidation of Fe atoms. Microstructural engineering of Fe-N-C is a viable approach to enhancing ORR activity and stability. Herein, CuN₅-single-atom nanozymes (SAzyme)-assisted Fe-N₅ catalysts (SA-Fe-N₅) were developed by introducing single-atom Cu to enhance Fe-N-C catalyst ORR performance. Electrochemical assessments indicated that SA-Fe-N₅ exhibited excellent ORR activity in alkaline solutions, with a half-wave potential and a diffusion-limited current density similar to that of commercial Pt/C. Calculations based on density functional theory indicated that a single copper atom can function as an electron donor, enhancing the electron density at the iron sites. This modification improves the adsorption and desorption energies for intermediates involved in the ORR process, ultimately boosting the ORR performance of the single-atom Fe-N₅ catalyst. Moreover, the introduction of the Cu site can be regarded as a catalase single-atom nanozyme (CAT-SAzyme), facilitating the decomposition of the byproduct H₂O₂ to H₂O and thereby enhancing the anti-Fenton activity during the ORR process. Notably, as a cathode catalyst in a zinc-air battery, SA-Fe-N₅ demonstrated an impressive power density of 217.8 mW cm^-2 alongside a current density of 257.3 mA cm^-2.

H₂O₂ production in coupled electrochemical systems, where H₂O₂ is generated through 2e‐pathway of water oxidation (2e‐WOR) at anode and 2e‐pathway of oxygen reduction (2e‐ORR) at cathode, offers an advanced alternative to the anthraquinone process. However, the efficiency of such coupled system is often hindered by the limited activity and selectivity of electrocatalysts. Herein, a dual‐functional catalyst composed of amorphous TiO₂ embedded in mesoporous carbon hollow spheres (TiO_x@MCHS) is reported, which exhibits exceptional electrocatalytic performance for both 2e‐WOR and 2e‐ORR. By employing TiO_x@MCHS‐loaded electrodes as both anode and cathode in a membrane‐free flow cell with 4 м K₂CO₃/KHCO₃ as electrolyte, a rate of 108.3 µmol min⁻¹ cm⁻² and a Faradaic efficiency (FE) of ≈145% for H₂O₂ production are achieved at a voltage of ≈2.5 V under a constant current of 240 mA (anode: 1 cm², cathode: 4 cm²). Experimental and computational results reveal the crucial role of low‐coordinated Ti in optimizing the adsorption of intermediates involved in the two electrode reaction pathways, thereby enhancing both activity and selectivity of these processes. This work establishes a new paradigm for the development of advanced electrocatalysts and the design of novel coupled‐electrolysis systems, enabling scalable and sustainable H₂O₂ electrosynthesis.

The electrocatalytic valorization of lignin provides a sustainable route to valuable chemicals under mild conditions, yet achieving high efficiency and selectivity remains challenging. Here, we develop gas diffusion electrodes (GDEs) modified with few‐layer graphene (GR) and multi‐walled carbon nanotubes (MWCNT) to enhance the oxygen reduction reaction (ORR) for efficient hydrogen peroxide (H ₂ O ₂ ) generation. The MWCNT‐modified GDE exhibits the highest surface area and conductivity, achieving over 80 % selectivity for H ₂ O ₂ via the two‐electron ORR pathway. Electrochemical lignin depolymerization using this optimized GDE yields 72.3 % low‐molecular‐weight aromatic compounds within 1 h. The MWCNT‐GDE demonstrates exceptional durability, maintaining stable performance across ten consecutive cycles. This work highlights the potential of MWCNT‐modified electrodes to advance scalable electrochemical lignin valorization through in‐situ H ₂ O ₂ generation.

Asymmetric electron distribution of single‐atom catalysts (SAC) is an important means of regulating intrinsic catalytic activity. However, limited by synthetic preparation methods, understanding of the mechanism of asymmetrically coordinated single‐atom catalysis is restricted. In this study, leveraging the micropore confinement effect, nitrogen and phosphorus‐doped microporous carbon is used as a substrate to successfully anchor singly dispersed Fe atoms, constructing the asymmetrically coordinated single‐atom Fe site coordinated with N and P atoms (Fe‐SAs/NPC). The existence of the Fe‐N₃P₁ site structure breaks the symmetry Fe‐N₄ in Fe‐SAs/NC, which would optimize the adsorption strength of intermediates. The resulting Fe‐SAs/NPC exhibits excellent ORR activity with a half‐wave potential of 0.91 V (0.1 m KOH), which is 40 mV higher than that of Fe‐SAs/NC (0.87 V). Combined with theoretical calculations, an in‐depth understanding of the asymmetric electronic configuration from the perspective of spin orbitals can enhance the electronic activity near the Fermi level and strengthen the adsorption of oxygen‐containing intermediates. This work provides new perspectives and ideas for understanding spin‐electronic behavior in catalytic processes. Furthermore, the Zn‐air battery constructed using Fe‐SAs/NPC exhibits a high power density of 187.7 mW cm⁻² and a specific capacity of 819.6 mAh g_Zn⁻¹ at 10 mA cm⁻².