Carbon Energy最新文献

Most advanced hydrogen evolution reaction (HER) catalysts show high activity under alkaline conditions. However, the performance deteriorates at a natural and acidic pH, which is often problematic in practical applications. Herein, a rhenium (Re) sulfide–transition-metal dichalcogenide heterojunction catalyst with Re-rich vacancies (NiS₂-ReS₂-V) has been constructed. The optimized catalyst shows extraordinary electrocatalytic HER performance over a wide range of pH, with ultralow overpotentials of 42, 85, and 122 mV under alkaline, acidic, and neutral conditions, respectively. Moreover, the two-electrode system with NiS₂-ReS₂-V₁ as the cathode provides a voltage of 1.73 V at 500 mA cm⁻², superior to industrial systems. Besides, the open-circuit voltage of a single Zn–H₂O cell with NiS₂-ReS₂-V₁ as the cathode can reach an impressive 90.9% of the theoretical value, with a maximum power density of up to 31.6 mW cm⁻². Moreover, it shows remarkable stability, with sustained discharge for approximately 120 h at 10 mA cm⁻², significantly outperforming commercial Pt/C catalysts under the same conditions in all aspects. A series of systematic characterizations and theoretical calculations demonstrate that Re vacancies on the heterojunction interface would generate a stronger built-in electric field, which profoundly affects surface charge distribution and subsequently enhances HER performance.

The dynamic surface self-reconstruction behavior in local structure correlates with oxygen evolution reaction (OER) performance, which has become an effective strategy for constructing the catalytic active phase. However, it remains a challenge to understand the mechanisms of reconstruction and to accomplish it fast and deeply. Here, we reported a photo-promoted rapid reconstruction (PRR) process on Ag nanoparticle-loaded amorphous Ni-Fe hydroxide nanosheets on carbon cloth for enhanced OER. The photogenerated holes generated by Ag in conjunction with the anodic potential contributed to a thorough reconstruction of the amorphous substrate. The valence state of unsaturated coordinated Fe atoms, which serve as active sites, is significantly increased, while the corresponding crystalline substrate shows little change. The different structural evolutions of amorphous and crystalline substrates during reconstruction lead to diverse pathways of OER. This PRR utilizing loaded noble metal nanoparticles can accelerate the generation of active species in the substrate and increase the electrical conductivity, which provides a new inspiration to develop efficient catalysts via reconstruction strategies.

Both sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are considered as promising candidates in grid-level energy storage devices. Unfortunately, the larger ionic radii of K⁺ and Na⁺ induce poor diffusion kinetics and cycling stability of carbon anode materials. Pore structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration, increasing the transport channels, and alleviating the volume change. However, traditional pore-forming agent-assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon materials. Herein, porous carbon materials (Ca-PC/Na-PC/K-PC) with different pore structures have been prepared with gluconates as the precursors, and the amorphous structure, abundant micropores, and oxygen-doping active sites endow the Ca-PC anode with excellent potassium and sodium storage performance. For PIBs, the capacitive contribution ratio of Ca-PC is 82% at 5.0 mV s⁻¹ due to the introduction of micropores and high oxygen-doping content, while a high reversible capacity of 121.4 mAh g⁻¹ can be reached at 5 A g⁻¹ after 2000 cycles. For SIBs, stable sodium storage capacity of 101.4 mAh g⁻¹ can be achieved at 2 A g⁻¹ after 8000 cycles with a very low decay rate of 0.65% for per cycle. This work may provide an avenue for the application of porous carbon materials in the energy storage field.

Rechargeable neutral aqueous zinc−air batteries (ZABs) are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs. However, the neutral ZABs normally possess poor oxygen evolution reactions (OERs) and oxygen reduction reactions performance, resulting in a large charge–discharge voltage gap and low round-trip efficiency. Herein, we demonstrate a sunlight-assisted strategy for achieving an ultralow voltage gap of 0.05 V in neutral ZABs by using the FeOOH-decorated BiVO₄ (Fe-BiVO₄) as an oxygen catalyst. Under sunlight, the electrons move from the valence band (VB) of Fe-BiVO₄ to the conduction band producing holes in VB to promote the OER process and hence reduce the overpotential. Meanwhile, the photopotential generated by the Fe-BiVO₄ compensates a part of the charging potential of neutral ZABs. Accordingly, the energy loss of the battery could be compensated via solar energy, leading to a record-low gap of 0.05 V between the charge and discharge voltage with a high round-trip efficiency of 94%. This work offers a simple but efficient pathway for solar-energy utilization in storage devices, further guiding the design of high energy efficiency of neutral aqueous ZABs.

Front cover image: The directional catalytic conversion of CO₂ into carboxylic acids via heterogeneous catalysis presents a promising pathway for achieving carbon neutrality and obtaining high-value chemicals. However, challenges such as CO₂ inertness and unsatisfactory product selectivity persist. In article number CEY2362, Zhang et al. summarize current research progress in producing carboxylic acids through photo-, electric-, and thermal catalysis, highlight strategies to construct catalysts, outline challenges and future research directions, offering insights into this area.

Hard carbon is regarded as a promising anode candidate for sodium-ion batteries due to its low cost, relatively low working voltage, and satisfactory specific capacity. However, it still remains a challenge to obtain a high-performance hard carbon anode from cost-effective carbon sources. In addition, the solid electrolyte interphase (SEI) is subjected to continuous rupture during battery cycling, leading to fast capacity decay. Herein, a lignin-based hard carbon with robust SEI is developed to address these issues, effectively killing two birds with one stone. An innovative gas-phase removal-assisted aqueous washing strategy is developed to remove excessive sodium in the precursor to upcycle industrial lignin into high-value hard carbon, which demonstrated an ultrahigh sodium storage capacity of 359 mAh g⁻¹. It is found that the residual sodium components from lignin on hard carbon act as active sites that controllably regulate the composition and morphology of SEI and guide homogeneous SEI growth by a near-shore aggregation mechanism to form thin, dense, and organic-rich SEI. Benefiting from these merits, the as-developed SEI shows fast Na⁺ transfer at the interphases and enhanced structural stability, thus preventing SEI rupture and reformation, and ultimately leading to a comprehensive improvement in sodium storage performance.

Back cover image: In article number cey2.434, Yang and co-workers reported vertical plane depth-resolved surface potential and carrier separation characteristics in flexible Cu₂ZnSn(S,Se)₄ solar cells. The band energy structure was predicted between the intragrains and the grain boundaries. To minimize carrier recombination, it is necessary to form an upward band bending structure over the entire absorber at the grain boundaries and to form a current path in the intragrains.

The world's population is growing, leading to an increasing demand for freshwater resources for drinking, sanitation, agriculture, and industry. Interfacial solar steam generation (ISSG) can solve many problems, such as mitigating the power crisis, minimizing water pollution, and improving the purification and desalination of seawater, rivers/lakes, and wastewater. Cellulosic materials are a viable and ecologically sound technique for capturing solar energy that is adaptable to a range of applications. This review paper aims to provide an overview of current advancements in the field of cellulose-based materials ISSG devices, specifically focusing on their applications in water purification and desalination. This paper examines the cellulose-based materials ISSG system and evaluates the effectiveness of various cellulosic materials, such as cellulose nanofibers derived from different sources, carbonized wood materials, and two-dimensional (2D) and 3D cellulosic-based materials from various sources, as well as advanced cellulosic materials, including bacterial cellulose and cellulose membranes obtained from agricultural and industrial cellulose wastes. The focus is on exploring the potential applications of these materials in ISSG devices for water desalination, purification, and treatment. The function, advantages, and disadvantages of cellulosic materials in the performance of ISSG devices were also deliberated throughout our discussion. In addition, the potential and suggested methods for enhancing the utilization of cellulose-based materials in the field of ISSG systems for water desalination, purification, and treatment were also emphasized.

Biomass-derived carbon is a promising electrode material in energy storage devices. However, how to improve its low capacity and stability, and slow diffusion kinetics during lithium storage remains a challenge. In this research, we propose a “self-assembly-template” method to prepare B, N codoped porous carbon (BN-C) with a nanosandwich structure and abundant pyridinic N-B species. The nanosandwich structure can increase powder density and cycle stability by constructing a stable solid electrolyte interphase film, shortening the Li⁺ diffusion pathway, and accommodating volume expansion during repeated charging/discharging. The abundant pyridinic N-B species can simultaneously promote the adsorption/desorption of Li⁺/PF₆⁻ and reduce the diffusion barrier. The BN-C electrode showed a high lithium-ion storage capacity of above 1140 mAh g⁻¹ at 0.05 A g⁻¹ and superior stability (96.5% retained after 2000 cycles). Moreover, owing to the synergistic effect of the nanosandwich structure and pyridinic N-B species, the assembled symmetrical BN-C//BN-C full cell shows a high energy density of 234.7 W h kg⁻¹, high power density of 39.38 kW kg⁻¹, and excellent cycling stability, superior to most of the other cells reported in the literature. As the density functional theory simulation demonstrated, pyridinic N-B shows enhanced adsorption activity for Li⁺ and PF₆⁻, which promotes an increase in the capacity of the anode and cathode, respectively. Meanwhile, the relatively lower diffusion barrier of pyridinic N-B promotes Li⁺ migration, resulting in good rate performance. Therefore, this study provides a new approach for the synergistic modulation of a nanostructure and an active site simultaneously to fabricate the carbon electrode material in energy storage devices.

The application of Li metal anodes in rechargeable batteries is impeded by safety issues arising from the severe volume changes and formation of dendritic Li deposits. Three-dimensional hollow carbon is receiving increasing attention as a host material capable of accommodating Li metal inside its cavity; however, uncontrollable and nonuniform deposition of Li remains a challenge. In this study, we synthesize metal–organic framework-derived carbon microcapsules with heteroatom clusters (Zn and Ag) on the capsule walls and it is demonstrated that Ag-assisted nucleation of Li metal alters the outward-to-inward growth in the microcapsule host. Zn-incorporated microcapsules are prepared via chemical etching of zeolitic imidazole framework-8 polyhedra and are subsequently decorated with Ag by a galvanic displacement reaction between Ag⁺ and metallic Zn. Galvanically introduced Ag significantly reduces the energy barrier and increases the reaction rate for Li nucleation in the microcapsule host upon Li plating. Through combined electrochemical, microstructural, and computational studies, we verify the beneficial role of Ag-assisted Li nucleation in facilitating inward growth inside the cavity of the microcapsule host and, in turn, enhancing electrochemical performance. This study provides new insights into the design of reversible host materials for practical Li metal batteries.