Photocatalytic NO removal over calcium-bridged siloxenes under ultraviolet and visible light irradiation. Issue 20 (10th May 2018)

• Record Type: Journal Article
• Authors: Imagawa, Haruo; Wu, Xiaoyong; Itahara, Hiroshi; Yin, Shu; Kojima, Kazunobu; Chichibu, Shigefusa F.; Sato, Tsugio
• Is Part Of: Dalton transactions. Volume 47:Issue 20(2018)
• Page Start: 7070
• Page End: 7076
• Publication Date: 2018-05-10
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt04310d
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Ca-Bridged siloxenes with a wide optical absorption band from the visible to ultraviolet region exhibited photocatalytic activity for NO removal. Abstract : Ca-Bridged siloxenes (Ca-siloxenes) composed of two-dimensional siloxene planes with Ca bridging were prepared and their photocatalytic properties for nitrogen oxide (NO) removal were investigated. Ca-Siloxenes were synthesized via a solid-state metathesis reaction using TaCl5 to extract Ca from CaSi2 with different Cl2 /Ca molar ratios of 0.25, 1.25 and 2.5 (CS0.25, CS1.25 and CS2.5, respectively) in an attempt to control the extent of Ca extraction. Ca-Siloxenes have a wide optical absorption band from the visible to ultraviolet region with absorption edges of 1.5, 2.9, and 3.1 eV for CS0.25, CS1.25, and CS2.5, respectively. Ca-Siloxenes exhibited photocatalytic activity for NO removal under irradiation with visible ( λ > 400 nm (<3.10 eV)) and ultraviolet light ( λ > 290 nm (<4.28 eV)). The photocatalytic activity was particularly improved by mixing the Ca-siloxene with acetylene black as a conductive material, which might have inhibited the recombination of photogenerated electrons and holes. The mixture of Ca-siloxene and acetylene black exhibited improved photocatalytic activity in the presence of 1 O2 as one of the active oxygen species formed under ultraviolet light irradiation.