Frontiers in Energy最新文献

The development of anti-corrosion and anti-poison electrocatalysts for both the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) is of great importance for effective applications of proton exchange membrane fuel cells (PEMFCs). In this study, a non-carbon supported catalyst, Pt/TiO₂-O_v, enriched with oxygen vacancies (O_v), is successfully synthesized using a microwave-assisted method. This catalyst is developed as a bifunctional electrocatalyst with superior contamination tolerance, enabling efficient HOR and ORR performance. The electronic metal-support interaction (EMSI) is leveraged to facilitate electron transfer between Pt and Ti atoms, induced by the formation of oxygen vacancy channels in the small-sized, high surface area TiO₂-O_v support. Notably, TiO₂-O_v has a lower bandgap than commercial TiO₂, enhancing its catalytic properties. In a 0.1 mol/L HClO₄ electrolyte, the normalized Pt mass activity (j_k,m) and specific activity (j_0,s) of Pt/TiO₂-O_v are 1.24 times higher than those of commercial Pt/C. Furthermore, Pt/TiO₂-O_v catalyst exhibits minimal current density decay after a prolonged durability testing under hydrogen and oxygen atmospheres. Remarkably, under a H₂/(1000×10⁻⁶) CO atmosphere, the relative retention rate of Pt/TiO₂-O_v significantly exceeds that of Pt/C catalyst, demonstrating its superior CO tolerance and promising potential for practical applications in PEMFCs. This study highlights the critical role of the strong metal-support interaction between the reducible oxide support and the noble metal Pt in improving long-term performance and CO poisoning resistance.

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising option for next-generation energy storage due to their abundant resources, affordability, eco-friendliness, and high safety levels. Manganese-based cathode materials, in particular, have garnered significant attention because of their high theoretical capacity and cost-effectiveness. However, they still face substantial challenges related to rate performance and cycling stability. To address these issues, researchers have developed various strategies. This review focuses on the key advancements in manganese-based cathode materials for AZIBs in recent years. It begins with a detailed analysis of the energy storage mechanisms in manganese-based cathodes. Next, it introduces a variety of manganese-based oxides, highlighting their distinct crystal structures and morphologies. It also outlines optimization strategies, such as ion doping (both monovalent ions and multivalent ions), the preparation of Mn-based metal-organic frameworks (MOFs), carbon materials coatings, and electrolyte optimization. These strategies have significantly improved the electrochemical performance of manganese-based oxide cathodes. By systematically analyzing these advancements, it aims to provide guidance for the development of high-performance manganese-based cathodes. Finally, it discusses prospective research directions for manganese-based cathodes in AZIBs.

The photocatalytic efficiency of lead-free Bi-based halide perovskites, such as Cs₃Bi₂X₉ (X = Br, I) for CO₂ reduction is often hindered by self-aggregation and insufficient oxidation ability. In this work, a visible-light-driven (λ > 420 nm) Z-scheme heterojunction photocatalyst composed of 0D Cs₃Bi₂I₉ nanoparticles on 1D WO₃ nanorods for photocatalytic CO₂ reduction and water oxidation is synthesized using an in situ growing approach. The resulting 0D/1D Cs₃Bi₂I₉/WO₃ Z-scheme heterojunction photocatalyst exhibits a visible-light-driven photocatalytic CO₂ reduction performance for selective CO production, achieving a selectivity of 98.7% and a high rate of 16.5 (µmol/(g·h), approximately three times that of pristine Cs₃Bi₂I₉. Furthermore, it demonstrates decent stability in the gas-solid photocatalytic CO₂ reduction system. The improved performance of Cs₃Bi₂I₉/WO₃ is attributed to the formation of the 0D/1D Z-scheme heterojunction, which facilitates charge transfer, reduces charge recombination, and maintains the active sites of both 0D Cs₃Bi₂I₉ for CO₂ reduction and 1D WO₃ for water oxidation. This work provides valuable insights into the potential of morphological engineering and the design of simultaneous Z-scheme heterojunction for lead-free halide perovskites.

The extensive utilization of fossil fuels has led to a significant increase in carbon dioxide (CO₂) emissions, contributing to global warming and environmental pollution, which pose major threats to human survival. To mitigate these effects, many researchers are actively employing state-of-the-art technologies to convert CO₂ into valuable chemicals and fuels, thereby supporting sustainable development. However, few studies have employed bibliometric methods to systematically analyze research trends in CO₂ reduction reaction (CO₂RR), resulting in limited macroscopic insights into this field. This study aims to conduct a scientometric analysis of academic literature on electrocatalytic, photocatalytic, and thermocatalytic CO₂RR from 2015 to 2023. Utilizing bibliometric analysis tools Citespace, Bibliometrix, and Vosviewer for data visualization, it establishes a knowledge framework for catalytic CO₂RR. The results show that China, the United States, and India are the top three countries with the highest number of published papers in this field, with China and the United States having the highest levels of collaboration. The journal Applied Catalysis B-Environmental published the most articles and received the highest citation count, with 3.4% of the articles in this field appearing in the journal and a total of 62526 citations. Keyword analysis revealed that terms like “CO₂RR,” “CO₂,” “conversion,” and “reduction” are the most frequently occurring, indicating key areas of focus. Additionally, “selectivity” and “heterojunction” emerged as prominent research hotspots. The discussion section highlights the current challenges in the field and proposes potential strategies to address these obstacles, providing valuable insights for research in the field of catalytic CO₂RR.

Photoelectrochemical (PEC) water splitting, particularly self-biased PEC systems, holds great promise for solar energy utilization. However, the limited transparency of most photoelectrodes presents challenges in fabricating tandem photoelectrodes with photovoltaic (PV) cells for self-biased water splitting. Herein, a novel self-biased hybrid system integrating photoelectrodes (TiO₂, BiVO₄), beam splitters (BSs), and PV cell was proposed to enhance solar energy utilization and PEC water splitting performance. The results indicate that the integration of BSs significantly improves the current densities of both self-biased PV-PEC systems and single PEC systems. The current density of self-biased water splitting system with BSs exceeds that of the conventional TiO₂ + BVO-PV system, and the intersection point of the I–V curves for the photoanodes and solar cell is closer to the maximum power output of the solar cell. The effective utilization of the solar spectrum by both the photoelectrode and the PV cell in the hybrid system with BSs significantly increases the power output by a factor of 18.8 compared to the conventional tandem self-biased system. The predicted results indicate that the hydrogen production rate of the system with BSs is 12.1 µmol/(h·cm²), while the STH efficiency is enhanced by a factor of 12.38 and 19.87 compared to conventional TiO₂ + BVO-PV and TiO₂/BVO-PV tandem PV-PEC systems, respectively, demonstrating the advantage of the water splitting system with spectral BSs. In conclusion, this work provides an innovative approach of achieving self-biased water splitting by coupling spectral BSs with a PV-PEC system, resulting in improved solar energy harvesting efficiency.