Constructing efficient polyimide(PI)/Ag aerogel photocatalyst by ethanol supercritical drying technique for hydrogen evolution

As one kind of promising photocatalyst, polyimide (PI) still suffers from poor light absorption, low charge transfer efficiency and small specific surface area. Herein, PI/Ag aerogel photocatalysts were designed by the sol-gel method and ethanol supercritical drying technique. As expected, Ag element in PI/Ag aerogel is in two forms, one is introduced into the imide ring of PI in the form of AgC bond, and another is the dopant Ag atoms. The former kind of Ag element can weaken the planar hydrogen bonding and improve the charge transfer efficiency, and the latter can form LSPR effect and promote the photoelectron-holes separation. Apart from that, the high specific surface area of the aerogel photocatalyst also favors the photocatalysis. All these effects boost the photocatalytic activity of the PI/Ag aerogel photocatalysts. The average rate of H2 production is up to 166.1 μmol h−1 g−1 for PI/Ag-1 aerogel, which is ca. 8 times as much as that of PI aerogel. The work supplies an efficient approach for constructing effective aerogel photocatalysts for H2 production.