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Proton ceramic fuel cells (PCFCs) are gaining attention due to their high energy conversion efficiency. However, the development of PCFCs is hindered by the lack of efficient and robust cathode materials. This article proposes a solution by introducing certain cationic deficiency into the Ba 0.9 La 0.1 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ (BLCFN) cathode matrix, which results in abundance of oxygen vacancies as well as enhanced proton defects. Consequently, the catalytic activity and hydration activity of the BLCFN oxygen electrode are improved during the reduction reaction process. Specifically, the polarization impedance (R p) of the (Ba 0.9 La 0.1) 0.95 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ (BL95CFN) decreases by 20% compared to the pristine BLCFN, reaching 0.12 Ω·cm2 at 700 °C in air. The R p of BL95CFN decreases by 12% in a steam environment of 20 vol%. This enhancement is attributed to the higher concentration of oxygen vacancies, which leads to an improved proton diffusion rate and hydration performance. The peak power density of the anode-supported BL95CFN | BZCYYb | BZCYYb-NiO single cell reaches 641 mW cm−2 at 700 °C, and the performance of this single cell remains stable for nearly 100 h. These findings highlight the vital role of adjusting oxygen vacancy and proton diffusion, providing a feasible strategy for improving the performance and stability of PCFC cathode materials. • An A-site deficiency engineered Ba 0.9 La 0.1 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ cathode is proposed. • A-site deficiency greatly enhanced ORR activity of Ba 0.9 La 0.1 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ. • Oxygen vacancy by introducing cationic defects, enhances catalytic activity and hydration reaction activity. • (Ba 0.9 La 0.1) 0.95 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ cathode showed good long-term stability. [ABSTRACT FROM AUTHOR]

Highly efficient and stable cathodes are significantly vital for solid oxide fuel cells (SOFCs). However, one of key impediment to the cathode development is the undesirable oxygen reduction activity and stability with exposure upon steam. Herein, we present a novel nanoparticles-decorated cathode, comprised of O2−/e−/H+ triple-conducting K+-doped BaCo 0.7 Fe 0.2 Y 0.1 O 3-δ (Ba 0.9 K 0.1 Co 0.7 Fe 0.2 Y 0.1 O 3-δ , BKCFY) matrix oxide and the mixed O2−/e− conducting nanoparticles of BaCoO 3-δ (BCO) through water-mediated exsolution process, exhibiting high activity and robust stability with exposure upon the steam. The cathode shows a low polarization resistance of 0.048 Ω cm2 at 700 °C when exposed upon humid air with 3% H 2 O, approximately 24% lower than that in dry air (0.065 Ω cm2 at 700 °C). Such improvement is mainly ascribed to the exsolved BaCoO 3- δ nanoparticles decorated on the porous BKCFY, which enlarged the triple phase boundary for oxygen reduction reaction. The increased oxygen vacancy concentration through K doping can accelerate the Ba and Co ions segregation to form BaCoO 3-δ with exposure upon the wet condition. Furthermore, K+ dopant with higher basicity than Ba2+ is beneficial for hydration behavior, which effectively promotes the catalytic activity under the water vapor. Moreover, the exsolved BaCoO 3-δ nanoparticles are socketed on the BKCFY matrix oxide, which ensures high stability for this hybrid cathode operated at 700 °C. The findings provide a promising approach to design the triple-conducting cathode for solid oxide fuel cells via water-mediated exsolution, which can also be applied for solid oxide electrolysis cells and membrane reactors. [Display omitted] [ABSTRACT FROM AUTHOR]

Symmetrical solid oxide fuel cells (SSOFCs) with identical anode and cathode have many benefits compared with traditional SOFCs. However, it is still a challenge to find high performance electrode materials with excellent catalytic activity and preferable stability under both reducing and oxidizing atmosphere. Here, a novel Ba 0.9 La 0.1 Co 0.7 Fe 0.2 Nb 0.1 O 3-δ (BLCFN) perovskite electrode has been developed as promising symmetrical electrode material for SSOFCs. The A-site non-stoichiometry introduced in BLCFN simultaneously enhances both the cathode and anode electrocatalytic performance. The cathode polarization resistance of BLCFN with 5% deficiency is decreased by 28.6% to 0.05 Ω·cm2 at 750°C in air, which can be mainly attributed to the increase of oxygen vacancy concentration via partial ionic defect. The BLCFN anode polarization resistance is reduced by 42.1% to 0.11 Ω·cm2 at 750°C in 5% H 2 /N 2. The promoted hydrogen oxidation reaction activity of BLCFN is related to the exsolved homogeneous Co-Fe nanoparticles from BL95CFN substrate in reducing atmosphere. The full cell with BL95CFN symmetrical electrodes displays high redox stability through reversing the flow of wet hydrogen and ambient air. Additionally, this SSOFCs with strong anchor characteristic of exsolved Co-Fe nanoparticles shows excellent coking-tolerance using methane fuel compared with traditional Ni-SDC anode. This work provides a potential way towards the development of high-performance, excellent redox-stable and coking-tolerant SSOFCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biotin-decorated celastrol-loaded ZIF-8 nanoparticles (CEL@ZIF-8@BIO) exhibit excellent water solubility and a high release rate in acidic environments. • CEL@ZIF-8@BIO effectively inhibits tumour proliferation and alleviates the toxicity of celastrol. • The mechanism of CEL@ZIF-8@BIO in anti-colorectal cancer is related to ferroptosis. Celastrol (CEL) has garnered significant interest for its anti-tumour properties and potential for colorectal cancer (CRC) treatment. However, its clinical use is constrained by its limited bioavailability and potential toxicity. Herein, a biotin-decorated CEL nano-drug delivery system using a zeolitic imidazolate framework (ZIF-8) as a carrier was synthesized, named CEL@ZIF-8@BIO. It exhibits excellent water solubility, efficient loading of CEL, and a high release rate in acidic environments. In vitro experiments demonstrated that CEL@ZIF-8@BIO inhibited proliferation, induced cell cycle arrest in G0/G1 phase, increased ROS production and reduced mitochondrial membrane potential in CRC cells. RNA-Seq analysis indicated that the anticancer mechanism of CEL@ZIF-8@BIO may be linked to ferroptosis as indicated by a significant increase in Fe2+ levels, oxidative stress, lipid peroxidation, and mitochondrial dysfunction in CRC cells. Furthermore, these effects could be reversed by ferroptosis inhibitor. In vivo research revealed that CEL@ZIF-8@BIO significantly inhibited the growth of CRC tumours and reduced the toxicity associated with CEL treatment. Taken together, the CEL@ZIF-8@BIO nano-drug delivery system shows great promise for CRC therapy due to its improved efficacy and reduced toxicity. [ABSTRACT FROM AUTHOR]