Facile synthesis of silicon-doped polymeric carbon nitride with enhanced photocatalytic performance

Non-metal doping is an effective strategy to enhance the photocatalytic performance of polymeric carbon nitride (CN), but silicon (Si) doping in CN has never been realized yet. Herein, Si-doped CN (CNSi) was firstly prepared via a simple calcination process, by using (NH4)(2)SiF6 as the Si source, and exhibits prominently enhanced photocatalytic activity in H-2 evolution from water splitting and for environmental purification. Its photocatalytic H-2 production rate under visible light irradiation is 2.24 mmol g(-1) h(-1) which is similar to 3 times that of CN, with an apparent quantum yield reaching similar to 7% at 420 nm. The photoactivity improvement of CNSi arises from its prominent increase in photoinduced charge separation and transfer efficiencies. The doping mechanism of Si in CN is well illustrated. CNSi exhibits a high chemical stability and also great potential for application in solar energy conversion and environmental remediation. This work provides a novel way to modify CN and paves an avenue for synthesizing other Si-containing CN photocatalysts. (C) 2019 Elsevier B.V. All rights reserved.