P-doped ultrathin g-C3N4/In2S3 S-scheme heterojunction enhances photocatalytic hydrogen production and degradation of ofloxacin

In this work, ultrathin lamellar g-C3N4/In2S3 S-scheme heterojunctions doped with P were synthesized by urea recrystallization and investigated to see which ratio was more favorable for photocatalysis. The P doping formed a new Fermi energy level and reduced the forbidden bandwidth. The ultrathin lamellar structure facilitated rapid charge transfer, and the formation of S-scheme heterojunction, the presence of the interfacial electric field, and band bending effectively separated strong redox-capable electron-hole pairs, thus significantly improving the photocatalytic performance. Among the prepared materials, the 50UP-C3N4/In2S3 photocatalyst with 50% UP-C3N4 mass fraction showed optimal photocatalytic H2 production performance, with a hydrogen production rate of 12,387 μmol·h-1·g-1. Moreover, it showed good performance in photocatalytic degradation, with a degradation efficiency of up to 90.2% of ofloxacin after 120 min of light exposure. This article provided a new perspective on the synthesis of other photocatalysts with carbazide-based S-scheme heterojunction structures.