Carbon Neutralization最新文献

Recent studies have indicated that the heterovalent states and vacancy defect structures in bimetallic oxysulfide play a crucial role in pollutant reduction reactions. However, systematic investigations into the synergistic coupling between heterovalent states and vacancy defect structures during the photocatalytic hydrogen evolution reaction (PHER) remain scarce. Herein, a tungsten/oxygen (W/O) co-doped Ag₂S bimetallic oxysulfide (AgWOS) with heterovalent W⁵⁺/W⁶⁺ states and sulfur vacancy (Vs) defects was synthesized via a facile thermohydrolysis method. The combination of W-doping and hydrazine-driven conditions induces abundant Vs defects, which act as active sites for water adsorption and activation, thereby facilitating proton generation in the PHER process. Moreover, the hydrazine-driven condition promotes the formation of heterovalent W⁵⁺/W⁶⁺ states, which provide efficient electron transfer channels between W⁵⁺ and W⁶⁺ to boost PHER performance. The optimized AgWOS-2 with a balanced heterovalent n(W⁵⁺)/n(W⁶⁺) ratio and a high concentration of Vs achieves an impressive PHER rate of 1074.2 µmol·h⁻¹ and an apparent quantum efficiency of 6.21% at 420 nm in pure water. Density functional theory calculations reveal that the synergy between heterovalent states and vacancy defects lowers the water dissociation barrier, accelerates *H generation, and boosts electron transfer between W⁵⁺ and W⁶⁺. Moreover, S-3p and O-2p orbital hybridization suppresses photocorrosion and improves catalyst stability, enabling AgWOS-2 to retain 91.6% of its initial PHER activity after ten cycles. This study elucidates the synergistic interaction mechanism between heterovalent states and vacancy defects in a bimetallic oxysulfide, offering valuable insights for the rational design of efficient and durable PHER catalysts.

Overcoming the sluggish acidic oxygen evolution reaction (OER) is critical for advancing proton exchange membrane water electrolysis (PEMWE) toward large-scale green hydrogen production, yet its development is hindered by the intrinsic trade-off between activity and stability. Herein, we introduce a controllable synthesis strategy to engineer RuO₂ assemblies from ultrasmall Ru nanocrystals supported on carbon via air annealing for efficient acidic OER. This process concurrently induces a Ru-to-RuO₂ crystal transformation and facilitates carbon thermal decomposition, yielding a catalyst (Ru-nano/C-300) with markedly enhanced electrochemically active surface area (ECSA) and superior OER performance, requiring only 218 mV at 10 mA cm⁻², and exhibiting a Tafel slope of 43.8 mV dec⁻¹ and a mass activity 21-fold higher than commercial RuO₂ (c-RuO₂) at 1.5 V vs. reversible hydrogen electrode (RHE). Tetramethylammonium cation (TMA⁺) poisoning experiments combined with in-situ spectroscopic analyses verify that the catalysts predominantly operate via the adsorbate evolution mechanism (AEM) pathway, while electron paramagnetic resonance (EPR) results indicate that suppressing oxygen vacancy formation is crucial for the reaction mechanism. These results demonstrate vacancy suppression coupled with morphology engineering as a powerful strategy to develop both efficient and durable catalysts for acidic OER.

The thermal gradient effect induced by bamboo particle size significantly influences the microstructure and sodium storage performance of derived hard carbon anodes. This study systematically investigates bamboo powders with three distinct particle sizes carbonized at 1400°C. Characterization reveals that medium-sized particles (~52.7 μm) optimize thermal gradients, yielding hard carbon (HCM) with balanced graphite-like domains (interlayer spacing ~0.397 nm) and closed pores. HCM exhibits superior reversible capacity (310 mAh g⁻¹ at 20 mA g⁻¹) and cycling stability (93.4% retention after 100 cycles). In contrast, smaller particles form excessive defects, while larger particles develop heterogeneous structures due to pronounced thermal gradients. Coin full cells (HCM//Prussian blue) demonstrate practical viability with 86.05% capacity retention after 200 cycles. This work elucidates the “particle size-thermal gradient-microstructure-performance” relationship, providing a design strategy for high-performance sodium-ion battery anodes.

Designing efficient and stable oxygen evolution reaction (OER) electrocatalysts for anion exchange membrane water electrolysis (AEMWE) systems is critical for sustainable energy conversion. Here, we demonstrate a strain engineering strategy through hydrothermal impregnation to anchor W single atoms on MnO₂ nanofibers, effectively modulating their electronic structure. The introduced tensile strain weakens the metal-oxygen bond strength, triggering a transition of the OER mechanism from the adsorbate evolution mechanism to the lattice oxygen-mediated mechanism-oxygen vacancy site mechanism (LOM-OVSM). The optimized W_2.06%-MnO₂ exhibits superior OER performance with an overpotential of 230 mV at 10 mA cm⁻². When applied in an AEMWE cell, it requires 1.77 V to drive 1 A cm⁻² and demonstrates continuous operation for over 450 h. This study provides fundamental insights into strain-induced modulation of reaction pathways and offers a practical strategy for designing advanced electrocatalysts toward scalable green hydrogen production.

Alkaline water electrolysis systems have emerged as a highly promising technology for hydrogen production. Metal-organic frameworks (MOFs) have demonstrated significant potential as electrodes due to their tunable pore structures, high-density active sites, and atomic-level design precision, offering enhanced catalytic activity and long-term stability under high current density conditions (> 500 mA cm⁻²). This review provides a systematic summary of recent advances in MOF-based materials for high-current-density alkaline water electrolysis. First, the key challenges posed by high current densities, such as mass transport limitations, bubble blockage, and structural deactivation, are discussed. Next, innovative material design strategies are introduced, focusing on critical aspects like tailoring metal active centers, functionalizing organic linkers to optimize the electronic structure, employing dimensional engineering (2D/3D hierarchical porous architectures) to enhance mass transfer, and introducing defect/interface engineering to improve activity and stability. The subsequence section evaluates the performance breakthroughs of MOFs and their derivatives under industrially relevant current densities (≥ 1 A cm⁻²). Finally, future research directions are highlighted, including enhancing intrinsic conductivity, unraveling dynamic catalytic mechanisms under operating conditions, and developing scalable electrode fabrication methods.

Electrochemical exfoliation (ECE) and dispersion technologies, as typical top-down electrochemical methods, exhibit outstanding advantages of being green, efficient, controllable, and scalable in the preparation of functional nanomaterials. ECE leverages an “intercalation–exfoliation” mechanism for the efficient and controllable production of few-/single-layer two-dimensional (2D) materials for energy storage. Electrochemical dispersion (ECD) is an efficient one-step method to prepare metal-based electrode nanomaterials, utilizing synergistic anodic oxidation and electric double-layer effects to transform bulk raw materials into functionalized nanomaterials with better dispersibility. This review systematically analyzes the electrochemical formation mechanisms of these two ways for synthesizing electrode materials under both direct current (DC) and alternating current (AC) power supplies. It centers on the mechanistic principles of two key approaches: the use of ECE to control the structure and properties of 2D layered electrodes, and the application of ECD to synthesize and optimize functionalized metal-based materials for energy storage devices. As promising electrochemical strategies for nanomaterial synthesis, ECE and ECD offer considerable promise for constructing and tailoring the properties of advanced energy storage electrodes.

The advancement of low-cost Pt-based intermetallic catalysts is of substantial importance for the effective implementation of high-efficiency zinc–air batteries (ZABs). However, designing efficient catalysts that exhibit both high catalytic activity and stability presents significant challenges. To overcome this issue, we have designed a hybrid catalyst comprising ordered PtM (M = Fe, Co, and Ni) intermetallic nanoparticles uniformly anchored to atomically dispersed M-N-C substrates by integrating a freezing microchemical displacement method with a high-temperature anchoring-reduction strategy. The Pt-NC layer formed during synthesis inhibits Pt nanoparticle migration and aggregation during annealing, which represents a key advantage over traditional methods that often require thick protective coatings. X-ray absorption fine structure analysis reveals that Pt–N bonds form between the nanoparticles and M-N-C support, building strong metal-support interactions through electron transfer and thus significantly enhancing structural stability. Furthermore, theoretical calculations reveal that the structurally ordered PtM intermetallics induce strong electron effects and optimize the d-band center of Pt. The synergistic effects of the ordered PtM electronic structure and its interaction with the M-N-C substrates result in significantly enhanced ORR activity for PtCo@CoNC. This catalyst achieves a mass activity of 1.23 mA/µg_Pt and a specific activity of 1.14 mA/cm²_Pt, outperforming the commercial Pt/C catalyst, which shows values of 0.16 mA/µg_Pt and 0.22 mA/cm²_Pt. When utilized in ZABs, the PtCo@CoNC demonstrates superior performance, yielding a higher open-circuit voltage (1.486 V) and peak power density (179.47 mW cm⁻²) compared to Pt/C-based devices, highlighting the practical advantages of the ordered PtM@MNC design.

Lithium-metal anodes offer exceptional theoretical capacity and the lowest electrochemical potential, but their practical use is limited by dendrite growth, unstable SEI formation, and large volume fluctuations. Carbon nanofibers (CNFs), with their low weight, high conductivity, and tunable structures, serve as effective hosts for regulating lithium deposition. Heteroatom doping further enhances lithiophilicity and interfacial stability: nitrogen creates abundant nucleation sites, oxygen and sulfur increase surface polarity and strengthen the SEI, and fluorine facilitates LiF-rich interphases for dendrite-free growth. Multi-element doping can also provide synergistic improvements in Coulombic efficiency and cycling stability. Despite these advances, challenges remain, including electrolyte consumption in high-surface-area structures, nonuniform dopant distribution, and potential degradation of CNF properties at high doping levels. This article summarizes recent progress in heteroatom-doped CNFs for lithium-metal anodes and outlines key limitations and future directions toward scalable, high-performance lithium-metal batteries.

The electrocatalytic CO₂ reduction reaction (CO₂RR) to formate provides a sustainable pathway for CO₂ conversion. Indium oxide (In₂O₃)-based catalysts have exceptional selectivity toward formate; however, the regulation and effects of crystalline structure on their performance need to be thoroughly investigated. Herein, we present the methodically controlled synthesis of In₂O₃ catalysts with unique crystallographic structures: rhombohedral In₂O₃ (h-In₂O₃), cubic In₂O₃ (c-In₂O₃), and mixed-phase In₂O₃ (h/c-In₂O₃), and conduct a comprehensive evaluation of their performance in CO₂RR to formate. Remarkably, the h-In₂O₃ catalyst demonstrates a Faradaic efficiency of formate (~95%) and current density surpassing both c-In₂O₃ and h/c-In₂O₃. In addition, the h-In₂O₃ catalyst exhibits excellent comprehensive performance in terms of operating potential range (−0.87 ~ −1.27 V vs. RHE), catalyst stability (70 h), pH range of electrolyte (3.00 ~ 14.00), and CO₂ concentration (20% ~ 100%). Density functional theory studies reveal that among various phases and facets of In₂O₃, the (104) facet of the h-In₂O₃ most effectively stabilizes the critical reaction intermediate, a contribution that is key to its enhanced activity for formate generation from CO₂RR. This investigation elucidates key insights into the engineering crystalline structure of In₂O₃ catalysts pertinent to CO₂RR, thereby presenting a methodical approach for developing highly efficient electrocatalysts.

Hydrogel electrolytes have emerged as promising candidates for flexible zinc-ion batteries (ZIBs) owing to their intrinsic mechanical robustness and biocompatibility. However, realizing high electrochemical performance and long-term operational stability remains a significant challenge, primarily due to the low ionic conductivity of hydrogel matrices and the uncontrolled growth of zinc dendrites, along with parasitic side reactions at the zinc anode interface. In this work, we propose a vertically aligned, zincophilic porous polyacrylamide-based hydrogel electrolyte (o-PAM) featuring strong interfacial adhesion. The unique structure, characterized by a locally alternating gel–liquid phase distribution, effectively overcomes the limitations of conventional hydrogel electrolytes by facilitating rapid Zn²⁺ transport and ensuring uniform ion deposition. This design bridges the ionic conductivity gap between gels and liquid electrolytes while mitigating Zn²⁺ concentration gradients. Moreover, the incorporation of multifunctional lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into the hydrogel not only enhances the electrolyte–anode interfacial adhesion, thereby lowering interfacial resistance, but also contributes to electrochemical stability. The abundant hydrogen bond acceptors in LiTFSI interact with water molecules to form hydrogen bonds, reducing the activity of free water and effectively suppressing side reactions such as hydrogen evolution (HER). As a result, the o-PAM hydrogel electrolyte delivers a high Zn²⁺ transference number of 0.65 and an impressive ionic conductivity of 20.14 mS cm⁻¹. In Zn||o-PAM||Zn symmetric cells, the electrolyte demonstrates outstanding cycling stability, with a lifespan of 3000 h at 1 mA cm⁻². Furthermore, a full Zn||o-PAM||I₂ cell exhibits remarkable capacity retention of 95.4% after 500 cycles at 1 mA cm⁻². These results highlight a promising strategy for the rational design of high-performance hydrogel electrolytes for next-generation zinc-ion batteries.