Ultrathin conjugated polymer nanosheets as highly efficient photocatalyst for visible light driven oxygen activation

Visible light induced photochemical synthesis represents a promising approach towards green and sustainable organic transformations. However, this protocol is greatly limited because of overly dependence on the noble metal complex based photosensitizers. In this work, we firstly reported newly designed imide based conjugated polymer nanosheets as metal-free heterogeneous photocatalysts for efficient visible light driven oxygen activation. Upon integrating perylene core with triazine- and heptazine- blocks, ultrathin polyimide nanosheets with broad light response, deep valence band level, and excellent oxygen activation property were synthesized. The polymer photocatalysts exhibited superior photocatalytic activity for amine oxidation at room temperature under visible light irradiation. The conversion yield reached up to 99 % with nearly 100 % selectivity as N-benzyl benzaldimine was found the exclusive product. The conversion rates of 250 mmol g(-1) h(-1) was two orders of magnitude higher than that of representative polymer photocatalysts and metal oxide based semiconductors.