title: Porous C3N4 nanolayers@N-graphene films as catalyst electrodes for highly efficient hydrogen evolution.
abstract: Pt-free electrocatalysts for hydrogen evolution reaction (HER) with high activity and low price are desirable for many state-of-the-art renewable energy devices, such as water electrolysis and photoelectrochemical water splitting cells. However, the design and fabrication of such materials remain a significant challenge. This work reports the preparation of a flexible three-dimensional (3D) film by integrating porous C3N4 nanolayers with nitrogen-doped graphene sheets, which can be directly utilized as HER catalyst electrodes without substrates. This nonmetal electrocatalyst has displayed an unbeatable HER performance with a very positive onset-potential close to that of commercial Pt (8 mV vs 0 mV of Pt/C, vs RHE @ 0.5 mA cm(-2)), high exchange current density of 0.43 mA cm(-2), and remarkable durability (seldom activity loss >5000 cycles). The extraordinary HER performance stems from strong synergistic effect originating from (i) highly exposed active sites generated by introduction of in-plane pores into C3N4 and exfoliation of C3N4 into nanosheets, (ii) hierarchical porous structure of the hybrid film, and (iii) 3D conductive graphene network.
authors.affiliation: School of Chemical Engineering, The University of Adelaide , Adelaide, South Australia 5005, Australia.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Duan
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
authors.forename: Mietek
authors.initials: M
authors.lastname: Jaroniec
authors.forename: Shi Zhang
authors.initials: SZ
authors.lastname: Qiao
keywords: carbon nitride nanolayers; hydrogen evolution reaction; nitrogen doped graphene; two-dimensional materials; van der Waals heterostructure