Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Hajime Hojo Last modified date:2022.04.01

Associate Professor / Department of Advanced Materials Science and Engineering / Faculty of Engineering Sciences


Papers
1. Ye, Xubin; Zhao, Jianfa; Das, Hena; Sheptyakov, Denis; Yang, Junye; Sakai, Yuki; Hojo, Hajime; Liu, Zhehong; Zhou, Long; Cao, Lipeng; Nishikubo, Takumi; Wakazaki, Shogo; Dong, Cheng; Wang, Xiao; Hu, Zhiwei; Lin, Hong-Ji; Chen, Chien-Te; Sahle, Christoph; Efiminko, Anna; Cao, Huibo; Calder, Stuart; Mibu, Ko; Kenzelmann, Michel; Tjeng, Liu Hao; Yu, Runze; Azuma, Masaki; Jin, Changqing; Long, Youwen, Observation of novel charge ordering and spin reorientation in perovskite oxide PbFeO3, NATURE COMMUNICATIONS, 10.1038/s41467-021-22064-9, 12, 1, 2021.03.
2. Pan, Zhao; Zhang, Mao-Hua; Nishikubo, Takumi; Sakai, Yuki; Yamamoto, Hajime; Hojo, Hajime; Fukuda, Masayuki; Hu, Lei; Ishizaki, Hayato; Kaneko, Satoru; Kawaguchi, Shogo; Koruza, Jurij; Roedel, Juergen; Azuma, Masaki, Polarization Rotation at Morphotropic Phase Boundary in New Lead-Free Na1/2Bi1/2V1-xTixO3 Piezoceramics, ACS APPLIED MATERIALS & INTERFACES, 10.1021/acsami.0c18482, 13, 4, 5208-5215, 2021.02.
3. Liu, Xin; Zhang, Ya; Matsushima, Shigenori; Hojo, Hajime; Einaga, Hisahiro, Photocatalytic oxidation process for treatment of gas phase benzene using Ti3+ self-doped TiO2 microsphere with sea urchin-like structure, CHEMICAL ENGINEERING JOURNAL, 10.1016/j.cej.2020.126220, 402, 2020.12.
4. Fukuda, Masayuki; Yamada, Ikuya; Murata, Hidenobu; Hojo, Hajime; Hernandez, Olivier J.; Ritter, Clemens; Tanaka, Katsuhisa; Fujita, Koji, Perovskite-Type CuNbO3 Exhibiting Unusual Noncollinear Ferrielectric to Collinear Ferroelectric Dipole Order Transition, CHEMISTRY OF MATERIALS, 10.1021/acs.chemmater.0c00444, 32, 12, 5016-5027, 2020.06.
5. Rongjie Qi, Pengfei Yu, Jiachen Zhang, Weiqi Guo, Yaoyu He, Hajime Hojo, Hisahiro Einaga, Qun Zhang, Xiaosong Liu, Zhi Jiang, Wenfeng Shangguan, Efficient visible light photocatalysis enabled by the interaction between dual cooperative defect sites, Applied Catalysis B: Environmental, 10.1016/j.apcatb.2020.119099, 274, 2020.10, Modifying photocatalyst with defects offers effective pathway to tailor light absorption properties, but may result in more sluggish kinetics. Therefore, enhanced light absorption often could not guarantee increased activity. Here, we report a dual defect strategy to extend light absorption with minimal loss in charge dynamics. Fine-tuned amount of dual defect, i.e., nitrogen defects and single-site copper, is simultaneously generated in polymer carbon nitride(PCN) through in-situ vapor diffusion method. Surface nitrogen defect extends the light absorption to long-wavelength via sub-band absorption. The interaction between nitrogen and single-site copper at certain concentration retains the charge dynamics by making the photogenerated electrons more delocalized through the newly-formed copper-nitrogen bonds. As a result, champion modified PCN exhibits robust hydrogen production activity, roughly 4.5-fold greater than the pristine counterpart in both visible and full light ranges. More intriguingly, this synergism provides PCN with efficient visible light activity even in faint tailing optical absorption region(>450 nm)..
6. Sou Yasuhara, Yosuke Hamasaki, Tsukasa Katayama, Takahiro Ao, Yoshiyuki Inaguma, Hajime Hojo, Maarit Karppinen, Anish Philip, Shintaro Yasui, Mitsuru Itoh, Modulating the Structure and Magnetic Properties of ϵ-Fe2O3 Nanoparticles via Electrochemical Li+ Insertion, Inorganic chemistry, 10.1021/acs.inorgchem.9b03302, 59, 7, 4357-4365, 2020.04, ϵ-Fe2O3, a metastable phase of iron oxide, is widely known as a roomerature multiferroic material or as a superhard magnet. Element substitution into ϵ-Fe2O3 has been reported in the literature; however, the substituted ions have a strong site preference depending on their ionic radii and valence. In this study, in order to characterize the crystal structure and magnetic properties of ϵ-Fe2O3 in the Fe2+/Fe3+ coexisting states, Li+ was electrochemically inserted into ϵ-Fe2O3 to reduce Fe3+. The discharge and charge of Li+ into/from ϵ-Fe2O3 revealed that Li+ insertion was successful. X-ray magnetic circular dichroism results indicated that the reduced Fe did not exhibit site preference. Increasing the Li+ content in ϵ-Fe2O3 resulted in decreased saturation magnetization and irregular variation of the coercive field. We present a comprehensive discussion of how magnetic properties are modified with increasing Li+ content using transmission electron microscopy images and considering the Li+ diffusion coefficient. The results suggest that inserting Li+ into crystalline ϵ-Fe2O3 is a useful tool for characterizing crystal structure, lithiation limit, and magnetic properties in the coexistence of Fe2+/Fe3+..
7. Xin Liu, Siyu Ding, Saki Shigenobu, Hajime Hojo, Hisahiro Einaga, Catalyst design of Pt/TiO2 microsphere for benzene oxidation under microwave irradiation, Catalysis Today, 10.1016/j.cattod.2020.05.021, 2020.01, Pt/TiO2 microspheres with sea-urchin like structures were prepared by sequential processes including the preparation of TiO2 by a hydrothermal method and the preheating of the TiO2, the deposition of Pt nanoparticles on the TiO2 surface, followed by post heating in O2/N2 and H2. The TiO2 and Pt/TiO2 catalysts were characterized by XRD, Raman, SEM, TEM and N2 adsorption studies. The average diameter of TiO2 microspheres was about 250 nm. The TiO2 microspheres were composed of TiO2 nanoparticles with the size of 20−30 nm. Pt particles with the size of 3 nm were highly dispersed on the TiO2 microsphere by liquid phase adsorption of colloidal Pt particles. The heating of TiO2 at 300 °C before and after the Pt deposition did not change the size of TiO2 microsphere and reduced the surface area from 238 to 137 m2 g-1. The Pt/TiO2 microsphere exhibited higher catalytic activity for benzene oxidation than Pt/TiO2 P25 under normal outer heating, whereas pristine TiO2 exhibited almost no activity. Activated carbon was used as a catalyst with a mixture of Pt/TiO2 microspheres when performing the catalytic reaction under microwave heating. The mixture of Pt/TiO2 and activated carbon showed higher benzene oxidation activity under microwave irradiation than under normal external heating. The mixture was applied to benzene adsorption-catalytic oxidation combined processes..
8. Takumi Nishikubo, Yuki Sakai, Kengo Oka, Tetsu Watanuki, Akihiko Machida, Masaichiro Mizumaki, Koki Maebayashi, Takashi Imai, Takahiro Ogata, Keisuke Yokoyama, Yoichi Okimoto, Shin Ya Koshihara, Hajime Hojo, Takashi Mizokawa, Masaki Azuma, Enhanced Negative Thermal Expansion Induced by Simultaneous Charge Transfer and Polar-Nonpolar Transitions, Journal of the American Chemical Society, 10.1021/jacs.9b10336, 2020.01.
9. Hao Guo, Xin Liu, Hajime Hojo, Xin Yao, Hisahiro Einaga, Wenfeng Shangguan, Removal of benzene by non-thermal plasma catalysis over manganese oxides through a facile synthesis method, Environmental Science and Pollution Research, 10.1007/s11356-019-04264-5, 26, 8, 8237-8247, 2019.03.
10. Shoma Hamada, Hajime Hojo, Hisahiro Einaga, Effect of catalyst composition and reactor configuration on benzene oxidation with a nonthermal plasma-catalyst combined reactor, Catalysis Today, 10.1016/j.cattod.2018.07.055, 144-152, 2019.07.
11. Hao Guo, Zhixiang Zhang, Hajime Hojo, Mingxia Chen, Hisahiro Einaga, Wenfeng Shangguan, Catalytic Removal of Benzene at Mild Temperature over Manganese Oxide Catalysts, Catalysis Surveys from Asia, 10.1007/s10563-019-09268-2, 23, 3, 199-209, 2019.09.
12. Kei Shigematsu, Takeshi Asakura, Hajime Yamamoto, Keisuke Shimizu, Marin Katsumata, Haruki Shimizu, Yuki Sakai, Hajime Hojo, Ko Mibu, Masaki Azuma, Room temperature ferromagnetism in BiFe1-xMnxO3 thin film induced by spin-structure manipulation, Applied Physics Letters, 10.1063/1.5024710, 112, 19, 2018.05.
13. Masaki Azuma, Yuki Sakai, Takumi Nishikubo, Masaichiro Mizumaki, Tetsu Watanuki, Takashi Mizokawa, Kengo Oka, Hajime Hojo, Makoto Naka, Systematic charge distribution changes in Bi- and Pb-3d transition metal perovskites, Dalton Transactions, 10.1039/c7dt03244g, 47, 5, 1371-1377, 2018.01.
14. Long Zhou, Jianhong Dai, Yisheng Chai, Huimin Zhang, Shuai Dong, Huibo Cao, Stuart Calder, Yunyu Yin, Xiao Wang, Xudong Shen, Zhehong Liu, Takashi Saito, Yuichi Shimakawa, Hajime Hojo, Yuichi Ikuhara, Masaki Azuma, Zhiwei Hu, Young Sun, Changqing Jin, Youwen Long, Realization of Large Electric Polarization and Strong Magnetoelectric Coupling in BiMn3Cr4O12, Advanced Materials, 10.1002/adma.201703435, 29, 44, 2017.11.
15. Junye Yang, Jianhong Dai, Zhehong Liu, Runze Yu, Hajime Hojo, Zhiwei Hu, Tunwen Pi, Yunliang Soo, Changqing Jin, Masaki Azuma, Youwen Long, High-Pressure Synthesis of the Cobalt Pyrochlore Oxide Pb2Co2O7 with Large Cation Mixed Occupancy, Inorganic Chemistry, 10.1021/acs.inorgchem.7b01646, 56, 19, 11676-11680, 2017.10.
16. Yuki Sakai, Junye Yang, Runze Yu, Hajime Hojo, Ikuya Yamada, Ping Miao, Sanghyun Lee, Shuki Torii, Takashi Kamiyama, Marjana Ležaić, Gustav Bihlmayer, Masaichiro Mizumaki, Jun Komiyama, Takashi Mizokawa, Hajime Yamamoto, Takumi Nishikubo, Yuichiro Hattori, Kengo Oka, Yunyu Yin, Jianhong Dai, Wenmin Li, Shigenori Ueda, Akihisa Aimi, Daisuke Mori, Yoshiyuki Inaguma, Zhiwei Hu, Takayuki Uozumi, Changqing Jin, Youwen Long, Masaki Azuma, A-Site and B-Site Charge Orderings in an s-d Level Controlled Perovskite Oxide PbCoO3, Journal of the American Chemical Society, 10.1021/jacs.7b01851, 139, 12, 4574-4581, 2017.03.
17. Hajime Hojo, Ryo Kawabe, Keisuke Shimizu, Hajime Yamamoto, Ko Mibu, Kartik Samanta, Tanusri Saha-Dasgupta, Masaki Azuma, Ferromagnetism at Room Temperature Induced by Spin Structure Change in BiFe1−xCoxO3 Thin Films, Advanced Materials, 10.1002/adma.201603131, 29, 9, 2017.03.
18. Kengo Oka, Hajime Hojo, Masaki Azuma, Katsuyoshi Oh-Ishi, Temperature-Independent, Large Dielectric Constant Induced by Vacancy and Partial Anion Order in the Oxyfluoride Pyrochlore Pb2Ti2O6-δF, Chemistry of Materials, 10.1021/acs.chemmater.6b02509, 28, 15, 5554-5559, 2016.08.
19. Runze Yu, Narumi Matsuda, Ken Tominaga, Keisuke Shimizu, Hajime Hojo, Yuki Sakai, Hajime Yamamoto, Kengo Oka, Masaki Azuma, High-Temperature Monoclinic Cc Phase with Reduced c/a Ratio in Bi-based Perovskite Compound Bi2ZnTi1-xMnxO6, Inorganic Chemistry, 10.1021/acs.inorgchem.6b00618, 55, 12, 6124-6129, 2016.06.
20. Bin Feng, Issei Sugiyama, Hajime Hojo, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara, Atomic structures and oxygen dynamics of CeO2 grain boundaries, Scientific Reports, 10.1038/srep20288, 6, 2016.02.
21. Keisuke Shimizu, Hajime Hojo, Yuichi Ikuhara, Masaki Azuma, Enhanced Piezoelectric Response due to Polarization Rotation in Cobalt-Substituted BiFeO3Epitaxial Thin Films, Advanced Materials, 10.1002/adma.201602450, 28, 39, 8639-8644, 2016.01.
22. Runze Yu, Hajime Hojo, Tetsu Watanuki, Masaichiro Mizumaki, Takashi Mizokawa, Kengo Oka, Hyunjeong Kim, Akihiko Machida, Kouji Sakaki, Yumiko Nakamura, Akane Agui, Daisuke Mori, Yoshiyuki Inaguma, Martin Schlipf, Konstantin Z. Rushchanskii, Marjana Ležaić, Masaaki Matsuda, Jie Ma, Stuart Calder, Masahiko Isobe, Yuichi Ikuhara, Masaki Azuma, Melting of Pb Charge Glass and Simultaneous Pb-Cr Charge Transfer in PbCrO3 as the Origin of Volume Collapse, Journal of the American Chemical Society, 10.1021/jacs.5b08216, 137, 39, 12719-12728, 2015.10.
23. Runze Yu, Hajime Hojo, Teruyasu Mizoguchi, Masaki Azuma, A new LiNbO3-type polar oxide with closed-shell cations
ZnPbO3, Journal of Applied Physics, 10.1063/1.4930034, 118, 9, 2015.08.
24. Hiroko Yokota, Tomoya Nozue, Shin Nakamura, Hajime Hojo, Mamoru Fukunaga, Pierre Eymeric Janolin, Jean Michel Kiat, Akio Fuwa, Ferroelectricity and weak ferromagnetism of hexagonal ErFe O3 thin films, Physical Review B - Condensed Matter and Materials Physics, 10.1103/PhysRevB.92.054101, 92, 5, 2015.08.
25. Runze Yu, Hajime Hojo, Kengo Oka, Tetsu Watanuki, Akihiko Machida, Keisuke Shimizu, Kiho Nakano, Masaki Azuma, New PbTiO3-type giant tetragonal compound Bi2ZnVO6 and its stability under pressure, Chemistry of Materials, 10.1021/cm504133e, 27, 6, 2012-2017, 2015.03.
26. K. Nabetani, Y. Muramatsu, K. Oka, K. Nakano, Hajime Hojo, M. Mizumaki, A. Agui, Y. Higo, N. Hayashi, M. Takano, M. Azuma, Suppression of temperature hysteresis in negative thermal expansion compound BiNi1-xFexO3 and zero-thermal expansion composite, Applied Physics Letters, 10.1063/1.4908258, 106, 6, 2015.02.
27. Sunseng Pyon, Kazutaka Kudo, Jun Ichi Matsumura, Hiroyuki Ishii, Genta Matsuo, Minoru Nohara, Hajime Hojo, Kengo Oka, Masaki Azuma, V. Ovidiu Garlea, Katsuaki Kodama, Shin Ichi Shamoto, Superconductivity in noncentrosymmetric iridium silicide Li2IrSi3, Journal of the Physical Society of Japan, 10.7566/JPSJ.83.093706, 83, 9, 2014.09.
28. Hajime Hojo, K. Fujita, H. Ikeno, T. Matoba, T. Mizoguchi, I. Tanaka, T. Nakamura, Y. Takeda, T. Okane, K. Tanaka, Magnetic structures of FeTiO3-Fe2O3 solid solution thin films studied by soft X-ray magnetic circular dichroism and ab initio multiplet calculations, Applied Physics Letters, 10.1063/1.4868638, 104, 11, 2014.03.
29. Hajime Hojo, Ko Onuma, Yuichi Ikuhara, Masaki Azuma, Structural evolution and enhanced piezoresponse in cobalt-substituted BiFeO3thin films, Applied Physics Express, 10.7567/APEX.7.091501, 7, 9, 2014.01.
30. Hajime Hojo, Ko Onuma, Yuichi Ikuhara, Masaki Azuma, Effect of oxygen pressure on electrical properties of BiFe 0.9Co0.1O3 thin films prepared by pulsed laser deposition, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.52.09KD09, 52, 9 PART2, 2013.09.
31. B. Feng, Hajime Hojo, T. Mizoguchi, H. Ohta, S. D. Findlay, Yukio Sato, N. Shibata, T. Yamamoto, Y. Ikuhara, Atomic structure of a σ3 [110]/(111) grain boundary in CeO 2, Applied Physics Letters, 10.1063/1.3682310, 100, 7, 2012.02.
32. Hajime Hojo, Eita Tochigi, Teruyasu Mizoguchi, Hiromichi Ohta, Naoya Shibata, Bin Feng, Yuichi Ikuhara, Atomic structure and strain field of threading dislocations in CeO 2 thin films on yttria-stabilized ZrO2, Applied Physics Letters, 10.1063/1.3575566, 98, 15, 2011.04.
33. Hajime Hojo, Teruyasu Mizoguchi, Hiromichi Ohta, Scott D. Findlay, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara, Atomic structure of a CeO2 grain boundary: The role of oxygen vacancies, Nano Letters, 10.1021/nl1029336, 10, 11, 4668-4672, 2010.11.
34. Hajime Hojo, Koji Fujita, Teruyasu Mizoguchi, Kazuyuki Hirao, Isao Tanaka, Katsuhisa Tanaka, Yuichi Ikuhara, Magnetic properties of ilmenite-hematite solid-solution thin films
Direct observation of antiphase boundaries and their correlation with magnetism, Physical Review B - Condensed Matter and Materials Physics, 10.1103/PhysRevB.80.075414, 80, 7, 2009.09.
35. Katsuhisa Tanaka, Koji Fujita, Seisuke Nakashima, Hajime Hojo, Tomohiko Matoba, Magnetic properties of disordered ferrite and ilmenite-hematite thin films, Journal of Magnetism and Magnetic Materials, 10.1016/j.jmmm.2008.11.069, 321, 7, 818-821, 2009.04.
36. Hajime Hojo, Koji Fujita, Katsuhisa Tanaka, Kazuyuki Hirao, Fabrication of p-type ferrimagnetic semiconductor thin films based on FeTiO3-Fe2O3 solid solution, Journal of Magnetism and Magnetic Materials, 10.1016/j.jmmm.2006.10.782, 310, 2 SUPPL. PART 3, 2105-2107, 2007.03.
37. Hajime Hojo, Koji Fujita, Katsuhisa Tanaka, Kazuyuki Hirao, Room-temperature ferrimagnetic semiconductor 0.6FeTiO3 ̇ 0.4Fe2O3 solid solution thin films, Applied Physics Letters, 10.1063/1.2357547, 89, 14, 2006.10.
38. Hajime Hojo, Koji Fujita, Katsuhisa Tanaka, Kazuyuki Hirao, Epitaxial growth of room-temperature ferrimagnetic semiconductor thin films based on the ilmenite-hematite solid solution, Applied Physics Letters, 10.1063/1.2337276, 89, 8, 2006.09.