摘要： 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 isotype g-C3N4/P-g-C3N4 heterojunction achieves a optimized 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.