Development of water splitting system using non-oxide photocatalysts under visible light irradiation

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05296
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: Osaka City University (2019-2020); Kyoto University (2018)
• Principal Investigator: Higashi Masanobu 大阪市立大学, 人工光合成研究センター, 特任准教授 (10711799)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 光触媒 / 水分解 / 可視光 / 硫化物 / 光電極

Outline of Final Research Achievements

Fabrication of non-oxide, such as metal sulfide, photoelectrode for stable water splitting was investigated. Cadmium sulfide (CdS) was deposited on transparent conductive glass electrodes by chemical bath method and then calcined under a nitrogen atmosphere. The electrodes were densified by 673 K calcination, and the amount of photocorrosion (deactivation by self-oxidation) of CdS during light irradiation was reduced. As a result, the cadmium cyanoferrate species formed by the reaction with the photodissolved cadmium ions and the ferrocyanide ions in the solution were densely formed on the CdS surface, suppressing further photocorrosion and improving the photoelectrochemical performance.

Free Research Field

光触媒・光電気化学

Academic Significance and Societal Importance of the Research Achievements

これまで、その不安定さから水分解において硫化物は主に光カソードの研究が行われており、光アノードの研究例は少なく、あってもトリエタノールアミンといった強力な犠牲還元剤を必要としていた。今回の研究により、硫化カドミウム光アノードの安定化に成功しており、今後、様々な硫化物材料を光アノードとして利用できる可能性を示している。また、それにより水分解効率の向上が期待でき、エネルギー・環境問題の解決に繋がっていく。