EcoEnergy最新文献

The electrochemical synthesis for value-added chemicals and fuels via carbon dioxide reduction reaction (CO₂RR) offers an effective route to close the anthropogenic carbon cycle and store renewable energy. Currently, the copper-based catalyst is still the only choice for generating various CO₂RR species beyond two electron products. However, the wide range of CO₂RR products generated on copper leads to low selectivity, and their low concentrations in electrolytes pose great costs in the downstream purification process and significantly challenge the scalability of this technology. To make this technology economically viable, enhancing product selectivity is crucial. In this review, we identify the primary CO₂RR species and discuss the latest insights into the reaction mechanisms controlling CO₂RR selectivity. Then, we examined factors that affect CO₂RR selectivity. Emphasizing these factors in catalyst design, we highlight the importance of advanced technologies to expand our knowledge and prospects for the future of the CO₂RR.

Seawater splitting is one of the desirable techniques for producing green hydrogen from the vast natural resource. Several reports about designing and fabricating efficient electrocatalysts to boost the oxygen evolution reaction and hydrogen evolution reaction have been published. However, they mainly focus on the electrodes, electrocatalysts, cost, and system stability. This article presents an overview of seawater splitting by highlighting the most challenging issues that complicate seawater electrolysis, such as durability, to guide future research in this important area. The strategy to launch life cycle assessments is described to evaluate the short and long-term impacts. Finally, the current challenges and prospective solutions are discussed.

The electrocatalytic C–N coupling reaction can achieve green and sustainable urea synthesis as well as CO₂ conversion and nitrogen fixation. However, the electrocatalytic C–N coupling reaction still faces challenges such as difficult adsorption and activation of reactive species, a large number of reactive intermediates, high reaction energy barriers, and inert reactive kinetics, resulting in the low urea yielding rate and Faradic efficiency. The development of efficient catalysts is key to improve the urea yielding rate and Faradic efficiency. This review covers the development history and basic principles of electrocatalytic C–N coupling for urea production, analyzes the nanostructure–catalytic activity relationship as well as the electronic structure–catalytic activity relationship, and discusses the main reaction mechanism of electrocatalytic C–N coupling for urea production. Based on these analyses, the concept of designing efficient C–N coupling catalysts is derived. Finally, the research status of electrocatalytic C–N coupling for urea synthesis is summarized, and the prospect for developing efficient electrocatalysts and C–N coupling mechanism are proposed.

Aqueous Zn-vanadium batteries have been attracting significant interest due to the high theoretical capacity, diverse crystalline structures, and cost-effectiveness of vanadium oxide cathodes. Despite these advantages, challenges such as low redox potential, sluggish reaction kinetics, and vanadium dissolution lead to inferior energy density and unsatisfactory lifespan of vanadium oxide cathodes. Addressing these issues, given the abundant redox groups and flexible structures in organic compounds, this study comprehensively reviews the latest developments of organic-modified vanadium-based oxide strategies, especially organic interfacial modification, and pre-intercalation. The review presents detailed analyses of the energy storage mechanism and multiple electron transfer reactions that contribute to enhanced battery performance, including boosted redox kinetics, higher energy density, and broadened lifespan. Furthermore, the review emphasizes the necessity of in situ characterization and theoretical calculation techniques for the further investigation of appropriate organic “guest” materials and matched redox couples in the organic-vanadium oxide hybrids with muti-energy storage mechanisms. The review also highlights strategies for Zn anode protection and electrolyte solvation regulation, which are critical for developing advanced Zn-vanadium battery systems suitable for large-scale energy storage applications.

Lithium (Li) metal anode is considered the “Holy grail” for the most promising next-generation rechargeable lithium metal batteries (LMBs) because of ultra-high theoretical specific capacity, ultra-low reduction potential and small density. However, uncontrolled lithium dendrite growth and inevitable side reaction seriously hindered the application of practical LMBs because of the deteriorating electrochemical performances and exacerbating the safety issues of LMBs. Thus, improving the electrochemical performances of LMBs by constructed of functionalized separator is promising for overcoming the above-mentioned challenges due to its' significantly advantages, such as enhancing mechanical and thermal stability, regulating the diffusion and migration of Li ions, homogenizing Li ion flux, forming protective layer on Li anode surfaces, etc. The relational investigations have significantly increased since 2020, while the comprehensive reviews on this research direction are relatively rare, especially in the detailed mechanism aspects. In this review, an overview in functionalized separator for stable LMBs is discussed in detail. Firstly, the current issues of LMBs are in-depth discussion and the general strategies are summarized. Subsequently, the requirements and limitations of separator, as well as the advantages of functionalized separator are summarized and reviewed. Most importantly, the protection mechanisms and research advances of advanced functionalized separator are comprehensively discussed and summarized. Furthermore, the applications of functionalized separator in rechargeable lithium metal-based full cells are reviewed. Finally, the challenges and potential opportunities for the future development and rational design of functionalized separator are highlighted in rechargeable LMBs to obtain future research directions related to the significant strategy of constructing dendrite-free and stable LMBs.

To obtain more cost-effective, non-noble catalysts for soot particle combustion of diesel engine cars, Bi₂Zr_1.9M_0.1O₇ (M = Mn, Fe, Co, Ni) compounds with partial lattice substitution have been designed and synthesized. All the substituted catalysts show significantly promoted activity, in the order of Bi₂Zr₂O₇ < Bi₂Zr_1.9Ni_0.1O₇ < Bi₂Zr_1.9Co_0.1O₇ < Bi₂Zr_1.9Fe_0.1O₇ < Bi₂Zr_1.9Mn_0.1O₇. The presence of NO improves the activity of all the samples due to the generation of active surface nitrates/nitrites. It has been proven that all the modified catalysts possess weaker Zr–O bonds, which facilitates the generation of more surface defects. Density functional theory calculations have confirmed that a more defective catalyst has a lower vacancy formation energy and O₂ adsorption energy. Isotopic ¹⁸O₂ labeling has also substantiated that a more defective catalyst has a faster gaseous O₂ exchange rate, thus improving the generation of more abundant soot reactive oxygen sites. The weakening of Zr-O bonds is the inherent factor to improve the catalytic activity. Mn-substitution can lead to the weakest Zr-O bonds in Bi₂Zr_1.9Mn_0.1O₇, which thus shows the optimal catalytic activity. Notably, the complete soot combustion can be achieved even at 360°C on this catalyst.

In this study, an entirely biodegradable and cations-rich Water hyacinth (WH) (Eichhorniacrassipes) extract is used as the electrolyte in electrochromic devices. The active electrodes are fabricated by applying a layer of nanocrystalline orthorhombic WO₃ onto 5 × 5 cm² fluorinated tin oxide plates using an indigenous formulation. The electrolyte utilized is the juice derived from WH plants without any modifications. The devices exhibit a transmission contrast of around 46% and 82% at wavelengths of 600 nm and >1000 nm, respectively, between the colored and bleached states. Additionally, they have a rapid coloration/bleaching time of 10 and 4.6 s with coloration efficiency value around 52 cm²/C. Investigations have indicated that the electrolyte's sodium ion concentration is likely the key behind the electrochromic process in this system. Using pectin as a natural gelling agent results in the formation of a gel polymer electrolyte that is mechanically resilient. The electrochromic systems created utilizing this electrolyte exhibit exceptional cyclic stability, lasting for 16 000 s of uninterrupted voltage sweep.

Aqueous Zn-ion battery (AZIB) is a new type of secondary battery developed in recent years. It has the advantages of high energy density, high power density, efficient and safe discharge process, non-toxic and cheap battery materials, simple preparation process, etc., and has high application prospects in emerging large-scale energy storage fields such as electric vehicles and energy storage grids. Currently, one of the main factors hindering the further development of AZIBs batteries is the lack of suitable cathode materials. This article briefly introduces the advantages and energy storage mechanisms of aqueous zinc-ion batteries. Based on the crucial role of cathode materials in AZIBs, several common cathode materials (such as manganese-based compounds, vanadium-based compounds, nickel/cobalt-based compounds, and lithium/sodium intercalated compounds) are reviewed, and strategies to improve their conductivity and cycling stability are summarized, focusing on modification strategies such as structural regulation, nanoengineering, doping modification, and compounding with high-conductivity materials. The article also points out the key development directions for cathode materials of AZIBs in the future.

Exploring a simple, rapid, and scalable synthesis method for the synthesis of high loading nonprecious metal sub-nanometer clusters (SNCs) electrocatalysts is one of the most promising endeavors today. Herein, an orderly-anchored top–down strategy is proposed for fabricating a new type of high loading WO_3-x SNCs on O-functional group-modified Ketjen black (WO_3-x-C(O)) to balance the high loading (49.29 wt.%) and sub-nanometer size. By optimizing the vacancy number, WO_2.71-C(O) has extremely large electrochemically active surface area (402 m² g⁻¹) and high turnover frequency value of 1.722 s⁻¹ at −50 mV (vs. reversible hydrogen electrode). The overpotential of WO_2.71-C(O) reaches 22 mV at a current density of 10 mA cm⁻², which is significantly better than the commercial Pt/C level (32 mV), achieving a breakthrough in the hydrogen evolution reaction (HER) catalytic activity of nonprecious metals in acidic environment. Theoretical calculations and in situ characterization show that this material allows for the enrichment of reactants (H*) and the optimization of intermediate adsorption, which leads to the enhancement of acidic HER catalytic activity.

MXenes are a new type of 2D transition metal carbon/nitride or carbonitride, which are composed of M_n+1AX_n phase material (MAX phase) through single-layer or thin-layer nanosheets obtained by exfoliation. Owning to unique two-dimensional layered structure, large specific surface area, excellent electrical conductivity and mechanical stability, the MXenes have quickly become a research hotspot due to their magnetic and other properties, and have been widely used in many fields such as electrochemical sensors, energy storage, catalysis, and adsorption. This article summarizes and introduces preparation methods of two-dimensional materials MXenes, and focus on reviewing their application research progress in the electrochemical sensors and environmental field in recent years, including detection of biomarkers and environmental pollutants, adsorption of heavy metals, adsorption of radiation metals, adsorption of organic matter, selective adsorption of carbon dioxide, membrane separation, sensors, electrocatalysis, photocatalysis, electromagnetic absorption and shielding, etc. A summary and review were conducted, and finally the existing problems and future development at this stage were analyzed.