Thin film formation of two-dimensional carbon nitride structure based on precisely-designed precursors and its application toward photoactive membrane reactors

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02174
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Keio University
• Principal Investigator: NODA Kei 慶應義塾大学, 理工学部(矢上), 教授 (30372569)
• Co-Investigator(Kenkyū-buntansha): 伊藤 彰浩 三重大学, 工学研究科, 教授 (90293901)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 二次元窒化炭素 / ナノ材料 / 光エネルギー変換

Outline of Final Research Achievements

Our newly-synthesized C3N5, which is one of the nitrogen-abundant carbon nitrides, showed a hydrogen (H2) production amount larger than that of conventional graphitic carbon nitride (g-C3N4) in photocatalytic water splitting with triethanolamine under visible light irradiation. Besides nanocomposites of tungsten trioxide (WO3) nanorods and C3N5 brought about further improvement in photocatalytic H2 production, which can be attributed to a direct Z-scheme mechanism.
In addition, g-C3N4 was uniformly deposited on the surfaces of anodized TiO2 nanotube arrays by thermal chemical vapor deposition (CVD), leading to the enhancement of photocatalytic H2 production over TiO2 under ultraviolet-visible light irradiation. Thermal CVD enables conformal deposition of graphitic carbon nitrides on surfaces with large specific surface areas. Our results observed for TiO2/g-C3N4 composites indicate that thermal CVD is effective for constructing photoactive membrane reactors with carbon nitrides.

Free Research Field

電子・電気材料工学

Academic Significance and Societal Importance of the Research Achievements

近年、ワイドギャップ半導体材料を用いた人工光合成（太陽光水素生成や二酸化炭素光還元）の研究開発が世界各地で活発に展開されている。本研究では、高分子半導体でもあり、炭素と窒素のみから成る金属フリーな窒化炭素材料を活用して、その薄膜形成技術や人工光合成反応に関する新しい知見を得るとともに、高機能光応答膜反応器の実現に向けた有益な成果を得ることができた。これらの成果は太陽エネルギーの有効利用やCO2削減等に寄与し得る、社会的に意義のあるものと言える。