Preparation of Stable Silver Nanoparticles Having Wide Red‐To‐Near‐Infrared Extinction

Autor: Shiori Kawamura, Kazuki Matsubara, Sotaro Sakai, Kazuhisa Sasaki, Masataro Saito, Kenji Saito, Masayuki Yagi, Wataru Norimatsu, Ryo Sasai, Michiko Kusunoki, Miharu Eguchi, Shu Yin, Yusuke Asakura, Tatsuto Yui
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Global Challenges, Vol 2, Iss 3, Pp n/a-n/a (2018)
Druh dokumentu: article
ISSN: 2056-6646
DOI: 10.1002/gch2.201700105
Popis: Abstract The synthesis of silver nanoparticles (AgNPs) within the interlayer space of transparent layered titania nanosheet (TNS) films is investigated. A considerable number of silver ions (≈70% against the cation exchange capacity of the TNS) are intercalated in the TNS films using methyl‐viologen‐containing TNSs as a precursor. The silver ion (Ag+)‐containing TNS films are treated with aqueous sodium tetrahydroborate (NaBH4), resulting in a gradual color change to bright blue. Various structural analyses clearly show that crystalline AgNPs are generated within the interlayer space of the TNSs. The NaBH4‐treated films show intense and characteristic near‐infrared (NIR) extinction spectra up to 1800 nm. The stability of the AgNPs within the TNS against oxygen and moisture is also investigated, and 96% and 82% of the AgNPs remain after standing in air for 1 month and 1 year, respectively. The NIR extinctions of the AgNP‐containing TNS films are further extended by employing different preparation procedures, for example, using sintered TNS films as starting materials and irradiating the Ag+‐containing TNSs with ultraviolet (UV) light. The obtained AgNP‐containing TNS films exhibit photochemical activities in the production of hydrogen from ammonia borane under visible‐light irradiation and the decomposition of nitrogen monoxide under UV‐light irradiation.
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