Ultrafine 1D graphene interlayer in g-C3N4/graphene/recycled carbon fiber heterostructure for enhanced photocatalytic hydrogen generation

The fabrication of one dimension (1D) graphene-based photocatalysts is highly intriguing as the charges can vectorially transfer along the length direction despite being challenging. Herein, we firstly reported the fabrication of 1D graphitic carbon nitride/graphene/recycled carbon fiber (g-CN/G/RCF) heterostructure fabricated by employing 1D RCF and facile steam activation strategy. The ultrafine graphene layers (<= 15 nm) were in situ generated by steam-activating RCF, and the g-C3N4 was then coated upon graphene layers by thermolysis of melamine/G/RCF composite. The as-produced g-CN/G/RCF hybrids offered increased photocatalytic hydrogen generation as graphene has excellent electric conductivity, as well as strong affinity to g-C3N4. The g-CN/G/RCF hybrid prepared under optimized condition showed the highest photocatalytic hydrogen evolution rate of 411.6 mu mol h(-1) g(-1), near 3.5 times higher than pure g-C3N4, and 2.1 times higher than g-CN/RCF (without graphene interlayer). In addition, such hybrid structure displayed excellent photostability for hydrogen generation, exhibiting no loss on hydrogen evolution rate within 24 h photocatalytic reaction. The present work shows great potential of 1D graphene on enhancing the photocatalytic activity of a heterojunction photocatalyst.