Facet-selective deposition of a silver–manganese dual cocatalyst on potassium hexatitanate photocatalyst for highly selective reduction of carbon dioxide by water

• Published in: Applied catalysis. B, Environmental Vol. 274; p. 119085
• Main Authors: Zhu, Xing, Yamamoto, Akira, Imai, Shota, Tanaka, Atsuhiro, Kominami, Hiroshi, Yoshida, Hisao
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.10.2020; Elsevier BV
• Subjects: Carbon dioxide; Catalytic activity; Chemical reduction; Core-shell structure; Dual cocatalyst; Facet-selective deposition; Manganese; Photocatalysis; Photocatalysts; Photocatalytic conversion of CO2; Potassium; Potassium hexatitanate; Silver; Species; Potassium hexatitanate; Facet-selective deposition; Dual cocatalyst; Photocatalytic conversion of CO2
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119085

[Display omitted] •The photocatalyst gave high CO formation rate with high CO selectivity (97%).•Ag nanoparticles deposited on reductive facets promoted CO evolution.•MnOx species deposited on oxidative facets enhanced oxygen production. Previously a silver–manganese dual cocatalyst loaded on a potassium hexatitanate crystal photocatalyst was reported to be efficient for photocatalytic reduction of CO2 to CO by using water as an electron source. In the present study, variously prepared silver–manganese dual cocatalysts were investigated to figure out their states and functions of Ag and MnOx species. Although an impregnation method provided various states of these species such as AgOx particles, core–shell structures, and oxidized aggregates, they gave negative effects on the photocatalytic activity. On the other hand, a simultaneous photodeposition method fabricated Ag and MnOx species on the long and short facets of the rod-like crystal, respectively, and these species functioned as each efficient promoter for the reductive and oxidative reactions in the photocatalysis. It was firstly evidenced that the clear separation of the reaction sites with the proper promoters is essential for the high efficiency in the photocatalytic CO2 reduction.