Phosphorus‐doped Isotype g‐C₃N₄/g‐C₃N₄: An Efficient Charge Transfer System for Photoelectrochemical Water Oxidation

Abstract

Constructing isotype g‐C3N4/g‐C3N4 heterojunction is an approach to improve the efficiency of g‐C3N4 towards solar‐assisted oxidation of water. Such functional configuration can effectively overcome the intrinsic drawback of rapid charge recombination of g‐C3N4. Here, a modified g‐C3N4, with homogeneous phosphorus doping, is prepared in this work through a phosphide‐involved gas phase reaction. The resulting P‐g‐C3N4 displays altered electronic structure, including upshifted band edge potential, narrowed band gap and improved electronic conductivity. These features allow P‐g‐C3N4 as an outstanding candidate to form isotype junction with pristine g‐C3N4. As expected, the accelerated charge separation and migration in target junction is validated by various measurements. The optimized isotype g‐C3N4/P‐g‐C3N4 heterojunction achieves a photocurrent as high as 0.3 mA cm−2 at 1.23 V vs RHE (AM 1.5G, 100 mW cm−2), representing 8‐fold's enhancement compared with pristine g‐C3N4. The present strategy for constructing g‐C3N4‐based isotype heterojunction networks is found effective for large‐scale manufacturing.

Three‐Dimensional Hierarchical Porous Carbon/Graphitic Carbon Nitride Composites for Efficient Photocatalytic Hydrogen Production

“…Previous reports have confirmed that the electron‐withdrawing group (HO−C=O) is favorable for promoting charge separation during photocatalysis . The high resolution N 1s XPS spectra of 3D C/g‐C 3 N 4 ‐3 can be decomposed into three different peaks centered at 398.8, 400.1, and 401.3 eV (Figure d), which are regarded as the sp 2 ‐bonded N(C−N=C), tertiary nitrogen N‐(C) 3 , and C‐NH, respectively, in accordance with those of bulk g‐C 3 N 4 .…”

g‐C3N4 Homophase Junction with High Crystallinity Using MoS2 as Cocatalyst for Robust Visible‐Light‐Driven Photocatalytic Pollutant Degradation

“…[39] Yu's work showed that homophase junction provided smoother channel for charge transfer. [39] Moreover, Wang, [40] Dong, [41] et al, [42][43][44] carried out researches about g-C 3 N 4 /g-C 3 N 4 heterojunction. As the defects in the catalyst become the center of charge recombination, the photocatalytic performance of g-C 3 N 4 based isotype heterojunction or homophase junction is not satisfactory.…”

Challenges and prospects about the graphene role in the design of photoelectrodes for sunlight-driven water splitting

“…5 Cu-based materials have shown great performance in comparison with other cited system, however, it suffers with serious problem of chemical stability due to the photocorrosion process, shortening its lifetime as PEC component. To boost the PEC cell performance using photocatalysts, several strategies have been pursued, for instance, extending the absorption spectra towards infrared, improve charge carrier kinetics and increase the active sites at the surface including the doping with anions or cations, [6][7][8] surface coupling with metals or semiconductors 9,10 and lm morphology design (nanoscaling).…”

“…Compared to graphite and carbon nanotubes, graphene exhibits much greater surface area and exceptional conductivity making it a potential candidate for different uses. Graphene has been reported in several applications such as a biosensors, 38 gas sensors, 8 electronic device design, 39 transistors, fuel cells, 40 photovoltaic devices, 41 photocatalytic hydrogen generation, etc.…”