論文2024

名前を赤で表記しているメンバーは当研究室の学生・院生、青で表記しているメンバーは当研究室の教員です。

原著論文

  1. シム ウェイジェン、グエン タンマイ、米澤 徹
    日本金属学会誌、印刷中．
  2. Sagar Ingavale, Mohan Gopalakrishnan, Phiralang Marbaniang, Woranunt Lao-atiman, Ahmad Azmin Mohamad, Mai Thanh Nguyen, Tetsu Yonezawa, Anita Swami, Soorathep Kheawhom
    In-situ self-assembly of molybdenum carbide and iron carbides heterostructure on Ndoped carbon for efficient oxygen reduction reaction
    Nanoscale, in press. 【RSC】(IF = 6.7)
    DOI: 10.1039/D4NR00799A (Published (web) 22 April 2024)
    【国際共同研究】
    Abstract: Identifying highly stable, cost-effective, platinum-free, and efficient electrocatalysts for oxygen reduction reactions (ORR) remains a formidable challenge. ORR is important for advancing fuel cell and zinc-air battery (ZAB) technologies towards cost-efficiency and environmental sustainability. This work presents the utilization of economically viable materials through a straightforward synthesis process, exhibiting the development of efficient Mo2C/Fe3C-NC catalysts, ingeniously derived from phosphomolybdic acid (PMA) and iron phthalocyanine (FePc). Results demonstrate that the optimized Mo2C/Fe3C-NC3 catalysts exhibit remarkable electrochemical performance, evidenced by an impressive onset potential of ~1.0 V versus RHE, a half-wave potential of 0.89 V, and a superior current density of about 6.2 mA cm-2. As for their performance in ZABs, the optimized catalysts reach a peak power density of 142 mW cm-2 at a current density of 200 mA cm-2. This synergy, coupled with the uniform distribution of Mo2C and Fe3C nanoparticles, greatly enhances the active catalytic sites and promotes electrolyte diffusion. Our approach diverges from traditional methods by employing an in-situ self-assembled heterostructure of Mo2C/Fe3C on nitrogen-doped carbon tubes, avoiding the conventional high-temperature hydrogen gas reduction process. Beyond serving as feasible alternatives to commercially available Pt/C catalysts, these materials hold promise for large-scale production owing to their affordability and simplicity of the synthesis technique. Such a breakthrough paves the way towards the realization of sustainable energy technologies and lays the groundwork for further exploration into amplifying the scalability and efficiency of ORR catalysts.
  3. Sorasak Klinyod, Nuttapon Yodsin, Mai Thanh Nguyen, Zikkawas Pasom, Sunpet Assavapanumat, Marisa Ketkaew, Pinit Kidkhunthod, Tetsu Yonezawa, Supawadee Namuangruk, Chularat Wattanakit
    Unraveling the Electrocatalytic Activity in HMF Oxidation to FDCA by Fine-tuning the Degree of NiOOH Phase over Ni Nanoparticles Supported on Graphene Oxide
    Small, in press. 【Wiley-VCH】(IF = 13.3)
    DOI: 10.1002/smll.202400779 (Published (web) 28 March 2024)
    【国際共同研究】

    Abstract: The development of an efficient electrocatalyst for HMF oxidation to FDCA has been in the early stages. Herein, the NiNPs/GO-Ni-foam is fabricated as an electrocatalyst for FDCA production. However, the electrocatalytic performance of the untreated NiNPs/GO-Ni-foam is observed with moderate Faradaic efficiency (FE) (73.0%) and FDCA yield (80.2%). By electrochemically treating the NiNPs/GO-Ni-foam in an alkaline solution with positive potential at different treatment durations, the degree of NiOOH on metal surfaces is changed. The distinctive electrocatalytic activity obtained when using the different NiOOH degrees allows to understand the crucial impact of NiOOH species in HMF electrooxidation. Enhancing the portion of the NiOOH phase on the electrocatalyst surface improves electrocatalytic activity in terms of FE and FDCA yield up to 94.8±4.8% and 86.9±4.1%, respectively. Interestingly, as long as the NiOOH portion on the electrocatalyst surface is preserved or regenerated, the electrocatalyst performance can be intact even after several catalytic cycles. The theoretical study via density functional theory (DFT) also agrees with the experimental observations and confirms that the NiOOH phase facilitates the electrochemical transformation of HMF to FDCA through the HMFCA pathway, and the potential limiting step of the overall reaction is the oxidation of FFCA to FDCA.

  4. Mai Thanh Nguyen, Pichaya Pattanasattayavong, and Tetsu Yonezawa
    Detailed discussion on structure of alloy nanoparticles synthesized by magnetron sputter deposition onto liquid poly(ethylene glycol)　【Review】
    Nanoscale Advances, 6(7), 1822-1836 (2024). 【RSC】【Open Access】(IF = 4.7)
    DOI: 10.1039/D3NA00998J (Published (web) 1 March 2024)
    【国際共同研究】

    Abstract: This paper is devoted to reviewing a decade of the development of vacuum sputter deposition onto liquid poly(ethylene glycol) (PEG) to prepare metal and alloy nanoparticles (NPs) with a controlled particle growth, size, structure, and composition. Especially, we have discussed the fine structures of alloy NPs obtained in PEG and compared them with those sputtered onto other non-volatile liquids. Finally, we have shared our prospect of applications for the resulting alloy NPs.

  5. Yung-Chieh Liu, Dhanapal Vasu, Guan-Lin Li, Jiaxin Jiang, Te-Wei Chiu, Liangdong Fan, Zhe-lun Ye, Wei-Hsin Hu, Wei Jian Sim, and Tetsu Yonezawa
    “Bi-functional CoCr2O4 hollow-sphere for enhanced oxygen evolution reaction and photocatalyst for harmful environmental pollutants removal”
    Ceramics International, in press. (2024). 【Elsevier】(IF = 5.2)
    DOI: 10.1016/j.ceramint.2024.03.056 (Published (web) 6 March 2024)
    【国際共同研究】

    Abstract: The development of a high-performance, cost-effective, and durable multifunctional semiconductor is crucial for clean energy and environmental remediation applications such as oxygen evolution reaction (OER) and photocatalysts. In this research, we have developed a hollow sphere-based spinel-structured CoCr2O4 (HS.CCO) for bi-functional applications. These hollow spheres exhibit excellent electrocatalytic OER performance under an alkaline (1 M potassium hydroxide (KOH)) medium, which displays a higher electrocatalytic ability. The spinel hollow spheres demonstrate favorable overpotentials and Tafel potentials of 180 mV and 162 mV/dec, respectively towards OER activity. On the other hand, as a photocatalysis, they portrayed outstanding degradation efficiency under visible light irradiation towards Congo red (CR) dye degradation. Within the short treatment time higher CR degradation efficiency is achieved. These photo-electroactive spinel hollow spheres accelerate efficient OER and visible-light-driven photocatalysis with remarkable stability. They serve as an excellent example of a multifunctional heterogeneous catalyst. Finally, the obtained results indicate the current needs and future demands for enhancing the prospects of multifunctional semiconductor catalysts.

  6. Mohan Gopalakrishnan, Wathanyu Kao-ian, Meena Rittiruam, Supareak Praserthdam, Piyasan Praserthdam, Wanwisa Limphirat, Mai Thanh Nguyen, Tetsu Yonezawa, and Soorathep Kheawhom
    3D Hierarchical MOF-Derived Defect-Rich NiFe Spinel Ferrite as a Highly Efficient Electrocatalyst for Oxygen Redox Reactions in Zinc–Air Batteries
    ACS Applied Materials & Interfaces, 16(9), 11537–11551 (2024). 【ACS】(IF = 9.5)
    DOI: 10.1021/acsami.3c17789 (Published (web) 15 February 2024)
    【国際共同研究】

    Abstract: The strategy of defect engineering is increasingly recognized for its pivotal role in modulating the electronic structure, thereby significantly improving the electrocatalytic performance of materials. In this study, we present defect-enriched nickel and iron oxides as highly active and cost-effective electrocatalysts, denoted as Ni0.6Fe2.4O4@NC, derived from NiFe-based metal–organic frameworks (MOFs) for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER). XANES and EXAFS confirm that the crystals have a distorted structure and metal vacancies. The cation defect-rich Ni0.6Fe2.4O4@NC electrocatalyst exhibits exceptional ORR and OER activities (ΔE = 0.68 V). Mechanistic pathways of electrochemical reactions are studied by DFT calculations. Furthermore, a rechargeable zinc–air battery (RZAB) using the Ni0.6Fe2.4O4 @NC catalyst demonstrates a peak power density of 187 mW cm–2 and remarkable long-term cycling stability. The flexible solid-state ZAB using the Ni0.6Fe2.4O4@NC catalyst exhibits a power density of 66 mW cm–2. The proposed structural design strategy allows for the rational design of electronic delocalization of cation defect-rich NiFe spinel ferrite attached to ultrathin N-doped graphitic carbon sheets in order to enhance active site availability and facilitate mass and electron transport.

書籍

  1. 微粒子分散・凝集講座　第３巻
    「分散凝集の応用」
    一般社団法人　日本ディスパージョンセンター　監修
    編者：米澤 徹、武田真一、藤井秀司、石田尚之
    近代科学社Digital
    （2024.4.19 初版発行）