A simple melamine-assisted exfoliation of polymeric graphitic carbon nitrides for highly efficient hydrogen production from water under visible light

Abstract

Compared to the bulk-CN, the quasi-2D-CN possesses a unique electronic structure, enlarged bandgap, prolonged lifetime, increased surface area and enhanced electronic transport, and exhibits highly efficient hydrogen production from water under visible light.

Hydrothermally Induced Oxygen Doping of Graphitic Carbon Nitride with a Highly Ordered Architecture and Enhanced Photocatalytic Activity

“…This may originate from a strong interaction between the graphitic layers of P‐CNO. Interestingly, unlike other reported porous or doped g‐C 3 N 4 , the diffraction peaks of P‐CNO are much sharper and higher than those of pristine bulk CN. This indicates that as‐prepared P‐CNO has a more ordered structure in both the in‐plane heptazine framework and the stacking of the conjugated aromatic layers.…”

“…The enlarged TEM image of P‐CNO shown in Figure c clearly demonstrates pores with diameters ranging from 10 to 120 nm. Further, the edges of the pores in P‐CNO are very sharp and poignant (Figures d and S4 d), which indicates that the pores are formed in the polymerization process caused by shrinkage of the precursor but not by etching the completed g‐C 3 N 4 layers (in this case, the pores are often in the shape of circles and the edges of the pores are usually smooth) . Thus, few defects are introduced and a highly ordered architecture is preserved in P‐CNO.…”

“…However, bulk g‐C 3 N 4 still suffers from some obstacles to achieve high photocatalytic activity, for instance, a low specific surface area, limited active sites, high rate of charge carrier recombination, and low degree of crystallinity . Several means have been developed to enhance the photocatalytic performance of g‐C 3 N 4 , such as elemental doping, the design of co‐catalysts, exfoliation of bulk g‐C 3 N 4 into 2 D nanosheets, and the formation of heterostructures with other materials …”

“…[6,7] However,b ulk g-C 3 N 4 still suffers from some obstacles to achieve high photocatalytic activity,f or instance,alow specific surfacea rea, limited active sites, high rate of chargec arrier recombination, and low degree of crystallinity. [8] Severalm eans have been developed to enhancet he photocatalytic performance of g-C 3 N 4 ,s uch as elemental doping, [9] the design of co-catalysts, [10,11] exfoliation of bulk g-C 3 N 4 into 2D nanosheets, [12] andt he formation of heterostructuresw ith other materials. [13] The formationo fn anosheets and porous structuresh as been provent ob eap ractical methodt oi mprove the photocatalytic properties of g-C 3 N 4 ,asitcan greatly increase the specific surface area and thus produce abundant catalytic active sites.…”

Exploring optoelectronic properties and mechanisms of layered ferroelectric K4Nb6O17 nanocrystalline films and nanolaminas

“…On the one hand, for global energy crisis, hydrogen is widely recognized as the fuel of the future, and photocatalytic water splitting into hydrogen has received significant attention 26–30 . Therefore, high-efficient and multifunctional materials for H 2 production are urgently desired.…”