In situ produced Co9S8 nanoclusters/Co/Mn-S, N multi-doped 3D porous carbon derived from eriochrome black T as an effective bifunctional oxygen electrocatalyst for rechargeable Zn-air batteries

In situ produced Co9S8 nanoclusters/Co/Mn-S, N multi-doped 3D porous carbon derived from eriochrome black T as an effective bifunctional oxygen electrocatalyst for rechargeable Zn-air batteries.

Hydrogel derived FeCo/FeCoP embedded in N, P-codoped 3D porous carbon framework as a highly efficient electrocatalyst for oxygen reduction reaction

Screening and constructing low cost, highly efficient and robust electrocatalysts with high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity is crucial for rechargeable metal–air batteries. Metal phosphides coupled with heteroatom doped carbon are promising candidates for oxygen electrodes. In this work, we demonstrate a facile strategy to synthesize cobalt phosphide anchored heteroatom (N,P) co-doped porous carbon (CoP/NP-HPC) through a one-step pyrolysis of bimetal–organic frameworks with a simple in situ phosphorization process. In alkaline solution, the obtained CoP/NP-HPC catalyst exhibits high bifunctional catalytic activity toward ORR and OER, comparable to commercial 20% Pt/C or even better, which is attributed to the synergistic effect between the CoP active sites and N,P co-doped carbon, and the porous framework as a channel benefiting the diffusion of reaction species. Notably, a rechargeable Zn–air battery with CoP/NP-HPC as the cathode electrocatalyst delivers a high power density of 186 mW cm−2, as well as good long-term charge/discharge cyclic stability, outperforming 20% Pt/C. The hybrid catalyst of CoP anchored heteroatom doped carbon provides a possibility and an opportunity to promote the development of low-cost and highly efficient bifunctional catalysts for ORR and OER in applications of metal–air batteries.

In situ growth of CoP nanoparticles anchored on (N,P) co-doped porous carbon engineered by MOFs as advanced bifunctional oxygen catalyst for rechargeable Zn–air battery

Developing high-efficient non-noble metal-based catalysts for oxygen reduction reaction (ORR) is an inevitable way to improve Zinc-air batteries' performance (ZAB). Herein, we report a Cu3P/MoP electrocatalyst (Cu3P/MoP@C) supported by hollow-porous-carbon nanospheres displaying high electrocatalytic activity and exceptional durability in alkaline media. The optimized ORR catalyst outperformed the benchmark Pt/C (20 wt%) and most recently reported Cu-/Mo-based catalysts in various aspects. X-ray photoelectron spectroscopy reveals that the excellent ORR performance originates from the charge transfer between of Cu3P and MoP species. Besides, the large specific surface area of Cu3P/MoP@C with mesoporous structure is particularly advantageous for the inner surface contact with electrolyte to accelerate ORR kinetics. Moreover, Cu3P/MoP@C also exhibits a large power density of 156 mW cm−2, a high round-trip efficiency, and superb stability over 231 h superior to Pt/C in the ZAB. This work offers a scalable and promising approach for the rational fabrication of hollow porous structure materials.

Electronic/mass transport increased hollow porous Cu3P/MoP nanospheres with strong electronic interaction for promoting oxygen reduction in Zn-air batteries

The low surface density of catalytic sites and undeveloped porosity have become a bottleneck for boosting the oxygen reduction reaction (ORR) activity of carbon catalysts. Herein, we propose a novel strategy for the synthesis of porous semi-tubular iron–nitrogen-doped-carbon nanostructures via a two-step calcination of a ferriporphyrin-based biomaterial by means of a natural tubulose nanoclay as a morphology-controlled template, followed by post Zn-activation and acid-leaching processes. The formation of mesopore-dominated semi-tubular carbons is beneficial for accelerating the ORR catalysis rate and improving the catalytic activity owing to the increased mass transport capacity of reactants to nitrogen-rich catalytic sites existing in the pores. The resultant doped-carbon catalyst not only displays excellent electrocatalytic behavior with an ORR onset potential of ∼1.01 V and a half-wave potential of ∼0.85 V, but also exhibits a maximum power density of ∼191 mW cm−2, comparable to that of a Pt catalyst in a primary Zn–air battery, suggesting a very promising candidate for prevalent energy-conversion devices. It is probably due to the production of mesopore-dominated semi-tubular structures, more active-nitrogen species and dense surface active sites. This work can pave a new way for the original design of low-cost and high-performance doped-carbon catalysts by using natural biomaterials for widespread application in electrochemical energy devices.

Boosting the primary Zn-air battery oxygen reduction performance with mesopore-dominated semi-tubular doped-carbon nanostructures

Self-assembly peptide nanotechnology has attracted much attention due to its regular and orderly structure and diverse functions. Most of the existing self-assembly peptides can form aggregates with specific structures only under specific conditions and their assembly time is relatively long. They have good biocompatibility but no immunogenicity. To optimize it, a self-assembly peptide named DRF3 was designed. It contains a hydrophilic and hydrophobic surface, using two N-terminal arginines, leucine, and two c-terminal aspartate and glutamic acid. Meanwhile, the c-terminal of the peptide was amidated, so that peptide segments were interconnected to increase diversity. Its characterization, biocompatibility, controlled release effect on antigen, immune cell recruitment ability, and antitumor properties were examined here. Congo red/aniline blue staining revealed that peptide hydrogel DRF3 could be immediately gelled in PBS. The stable β-sheet secondary structure of DRF3 was confirmed by circular dichroism spectrum and IR spectra. The observation results of cryo-scanning electron microscopy, transmission electron microscopy, and atomic force microscopy demonstrated that DRF3 formed nanotubule-like and vesicular structures in PBS, and these structures interlaced with each other to form ordered three-dimensional nanofiber structures. Meanwhile, DRF3 showed excellent biocompatibility, could sustainably and slowly release antigens, recruit dendritic cells and promote the maturation of dendritic cells (DCs) in vitro. In addition, DRF3 has a strong inhibitory effect on clear renal cell carcinoma (786-0). These results provide a reliable basis for the application of peptide hydrogels in biomedical and preclinical trials.

/pdf/a-rapid-self-assembly-peptide-hydrogel-for-recruitment-and-wevw5uih.pdf

A Rapid Self-Assembly Peptide Hydrogel for Recruitment and Activation of Immune Cells

Patient-derived organoid (PDO) models have been widely used in precision medicine. The inability to standardize organoid creation in pre-clinical models has become apparent. The common mouse-derived extracellular matrix can no longer meet the requirements for the establishment of PDO models. Therefore, in order to develop effective methods for 3D cultures of organoids, we designed a self-assembling peptide, namely DRF3, which can be self-assembled into ordered fibrous scaffold structures. Here, we used the co-assembly of self-assembling peptide (SAP) and collagen type I, fibronectin, and laminin (SAP-Matrix) to co-simulate the extracellular matrix, which significantly reduced the culture time of PDO, improved the culture efficiency, and increased the self-assembly ability of cells. Compared with the results from the 2D cell line, the PDO showed a more significant expression of cancer-related genes. During organoid self-assembly, the expression of cancer-related genes is increased. These findings provide a theoretical basis for the establishment of precision molecular modeling platforms in the future.

/pdf/a-self-assembling-peptide-as-a-model-for-detection-of-2ixrlqoi.pdf

A Self-Assembling Peptide as a Model for Detection of Colorectal Cancer

Objective To investigate the effect of chiral self-assembled peptides SciobioII and Sciobio IV on the repair of anterior cruciate ligament injury. Methods The structure of the self-assembled peptides SciobioII and Sciobio IV was analyzed by circular dichroism, transmission electron microscopy, and aniline blue staining; the activity and morphology of human ligament fibroblasts (HLF) in 3D cell culture matrix were detected by acridine orange/ethidium bromide (AO/EB) staining and FITC-phalloidin staining. The rabbit model of anterior cruciate ligament injuries was established and the effects of self-assembled peptides on the ligament repair were analyzed by HE staining and immunohistochemistry. Results The self-assembled peptides SciobioII and Sciobio IV formed a stable β-sheet after self-assembling in PBS for 24 hours, and futher constructed a nanofiber network structure, which was suitable for 3D cell culture. Human ligament fibroblasts maintained a round shape and grew vigorously in the 3D cell culture media constructed by self-assembled peptides. Animal experiments showed that the self-assembled peptide SciobioII promoted the repair rate of anterior cruciate ligament injury in rabbit. Conclusion Chiral self-assembled peptides Sciobio II and Sciobio IV can be used for 3D cell culture and repair of anterior cruciate ligament injury in rabbit.

Ruyue Luo

Papers

Boosting the primary Zn-air battery oxygen reduction performance with mesopore-dominated semi-tubular doped-carbon nanostructures

A Rapid Self-Assembly Peptide Hydrogel for Recruitment and Activation of Immune Cells

A Self-Assembling Peptide as a Model for Detection of Colorectal Cancer

[Chiral self-assembled peptides Sciobio II and Sciobio IV for 3D cell culture and repair of anterior cruciate ligament injury in rabbit].