Effective enhancement of electron migration and photocatalytic performance of nitrogen-rich carbon nitride by constructing fungal carbon dot/molybdenum disulfide cocatalytic system

To find a cocatalyst that can replace noble metals, fungal carbon dot (CD) modified molybdenum disulfide (MoS2) cocatalyst system was designed. The composites were prepared by hydrothermal and calcination methods with different ratios of CDs, MoS2 and nitrogen-rich carbon nitride (p-C3N5). p-C3N5 has excellent electronic properties, and MoS2 modified by CDs (D-MoS2) can significantly enhance the photocatalytic performance of p-C3N5 by improving the photogenerated electron migration efficiency. The experiments showed that the developed CDs/MoS2/C3N5 composites exhibited excellent performance in both photocatalytic hydrogen (H-2) evolution and methylene blue (MB) degradation, with CMSCN5 (D-MoS2 with 5% mass fraction) showing the best photocatalytic activity. The corresponding H-2 evolution rate of CMSCN5 was 444 mu mol g(-1)h(-1) and 1.45 times higher than that of unmodified p-C3N5, by 120 min, the removal rate of MB was up to 93.51%. The 5 cycle tests showed that CMSCN5 had great stability. The high charge mobility and high density of H-2 evolution active sites of MoS2 nanosheets, together with the electron storage and transfer properties of CDs can obviously improve electron migration and reduce the photogenerated carrier recombination on the p-C3N5 surface. The design and preparation of such composites offer broad prospects for the development of photocatalytic systems with noble metal-free cocatalysts. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

A fungal carbon dot (CD) modified molybdenum disulfide (MoS2) cocatalyst system was developed to replace noble metals in photocatalytic reactions. The designed CDs/MoS2/C3N5 composites exhibited excellent performance in photocatalytic hydrogen evolution and methylene blue degradation, showing promising prospects for noble metal-free photocatalytic systems.