Ruihong Wang

Heterojunction catalysts have been demonstrated to significantly enhance photocatalytic CO₂ reduction activity. However, the direction and rate of charge transfer at the catalyst interfaces remain the primary limiting factors for catalytic performance. In this study, a ternary heterojunction MgTi₂O₅/TiO₂/g-C₃N₄ was prepared via in situ composite synthesis, and rare earth single-atom Ho, with its abundant 4f electron energy levels, was utilized as an electron transfer channel within the heterojunction. This approach effectively facilitated electron transfer at the catalyst interface, and its photocatalytic activity and mechanism were thoroughly investigated. Remarkably, the catalyst exhibited distinct charge transport mechanisms under visible light and ultraviolet light. In the absence of a sacrificial agent, MT:CN-1 demonstrated optimal performance under visible light, achieving a CO yield of 31.42 μmol·g^-1·h^-1, which is 9.8 times higher than that of pristine CN. Under ultraviolet light, MT:CN-2 exhibited the best performance, with a CO yield of 40.61 μmol·g^-1·h^-1, representing a 4.2-fold enhancement compared to CN. Furthermore, the charge transfer mechanism of the catalyst was elucidated using in situ XPS and femtosecond transient fluorescence spectroscopy techniques.

The picture shows Co single atom-decorated RuO₂nanoparticles anchored on nitrogen-doped ultrathin carbon nanosheet (Co_SA-RuO₂-NUCN). The bifunctional catalytic process (ORR/OER) of Co_SA-RuO₂-NUCN is also fully presented.

Manipulating electronic structure of alloy‐based electrocatalysts can eagerly regulate its catalytic efficiency and corrosion resistance for water splitting and fundamentally understand the catalytic mechanisms for oxygen/hydrogen evolution reactions (OER/HER). Herein, the metallic Co‐assisted Co₇Fe₃ alloy heterojunction (Co₇Fe₃/Co) embeds in a 3D honeycomb‐like graphitic carbon is purposely constructed as a bifunctional catalyst for overall water splitting. As‐marked Co₇Fe₃/Co‐600 displays the excellent catalytic activities in alkaline media with low overpotentials of 200 mV for OER and 68 mV for HER at 10 mA cm⁻². Theoretical calculations reveal the electronic redistribution after coupling Co with Co₇Fe₃, which likely forms the electron‐rich state over interfaces and the electron‐delocalized state at Co₇Fe₃ alloy. This process changes the d‐band center position of Co₇Fe₃/Co and optimizes the affinity of catalyst surface to intermediates, thus promoting the intrinsic OER/HER activities. For overall water splitting, the electrolyzer only requires a cell voltage of 1.50 V to achieve 10 mA cm⁻² and dramatically retains 99.1% of original activity after 100 h of continuous operation. This work proposes an insight into modulation of electronic state in alloy/metal heterojunctions and explores a new path to construct more competitive electrocatalysts for overall water splitting.

Organic afterglow materials based on carbon dots (CDs) have aroused extensive attention for their potential applications in sensing, photoelectric devices, and anticounterfeiting. Effective methods to control the CD structure and modulate the energy levels are critical but still challenging. Here, we demonstrate a method to modulate the afterglow emission of CDs@SiO₂ composites by controlling the carbonization degree of CDs with variable calcining temperatures. The CDs@SiO₂-Raw prepared with a hydrothermal bottom-up synthesis method shows a more polymerized structure of CDs with low carbonization degree, which emits long-lived thermally activated delayed fluorescence (TADF) with the lifetime of 252 ms. After calcination at 550 °C, CDs@SiO₂-550 exhibits a larger conjugated π-domain structure with higher carbonization degree, thus inducing room-temperature phosphorescence (RTP) emission with a lifetime of 451 ms. The transformation of the carbonization degree of CD structures leads to changes in energy levels and ΔE_ST, which affect their afterglow luminescence behaviors. This work proposes a new concept to modulate the afterglow emission of CDs@SiO₂ composites and forecasts potential applications of CD-based afterglow materials.

A 2D/2D/2D Ti ₃ C ₂ T _x @TiO ₂ @MoS ₂ heterostructure was achieved via a facile one-step hydrothermal strategy; it showed an excellent gas sensing performance to NO ₂ , which is mainly attributed to numerous active sites and unique three-phase heterointerfaces.

Searching for high-efficient, good long-term stability, and low-cost electrocatalysts toward oxygen reduction reaction (ORR) is highly desirable for the development of sustainable energy conversion devices. Iron–nitrogen doped carbon (Fe–N/C) catalysts have been recognized as the most promising candidates for traditional Pt-based catalysts that benefit from their high activity, excellent anti-poisoning ability, and inexpensiveness. Here, a super-dispersed and high-performance Fe–N/C catalyst was derived from chemically Fe-doped zeolitic imidazolate frameworks (ZIFs) by directly bonding Fe ions to imidazolate ligands within 3D frameworks. It produced a series of catalysts, whose sizes could be tuned in the range from 62 to over 473 nm in diameter. After rationally regulating the component and heating treatment, the best ORR activity was measured for the catalyst with a size of 105 nm, which was obtained when the Fe³⁺/Zn²⁺ molar ratio was 0.05 and carbonization temperature was 900 °C. It exhibited a high onset potential (E_onset = 0.99 V) and half-wave potential (E_1/2 = 0.885 V) compared with a commercial 20% Pt/C catalyst (E_onset = 0.10 V, E_1/2 = 0.861 V) as well as much better durability and methanol resistance in an alkaline electrolyte.

Owing to unique lamellar nanostructures, 2D inorganic materials are considered as promising candidates in energy storage and conversion. In this paper, a facile two‐step synthesis is developed to fabricate 3D hierarchical dual Fe₃O₄/MoS₂ nanosheets (HD‐FMNs), in which few‐layered MoS₂ nanosheets are anchored in 3D Fe₃O₄ nanosheet network to form the heterojunction structure. Furthermore, it is proved that the synergistic effects on both electron/lithium‐ion transport kinetics and mechanical cycling stability benefit from Fe₃O₄/MoS₂ nanosheet incorporation in 3D HD‐FMN anode for lithium‐ion batteries (LIBs), resulting in the dramatically enhanced performance. The Fe₃O₄ nanosheet incorporation effectively improves the electronic conductivity due to its half‐metal characteristic, while the defect‐rich structure in the MoS₂ nanosheets can facilitate the lithium ion transport. When tested as potential anode materials, 3D HD‐FMNs exhibit a high reversible capacity (650 mAh g⁻¹) at current rate of 5 C (1 C = 1 A g⁻¹) after superior long‐term cycles (1000 times), as well as an excellent rate capability even at high current rates. The outstanding electrochemical property of 3D HD‐FMNs allows their application in high‐performance anode materials for next‐generation LIBs. This strategy also opens a new way to design the novel 2D composite materials for electrochemical devices.