Biochar-derived flower-like Co-Mo2C spheres/g-C3N4 photocatalyst: Engineering morphology configuration and electronic structure tuning

As a class of highly recalcitrant water contaminants, pharmaceuticals and personal care products (PPCPs) have raised considerable concerns. Here, we develop a biochar-derived flower-like Co-Mo2C sphere/g-C3N4 (CMCN) heterostructure photocatalyst for typical PPCPs degradation. The flower-like Co-Mo2C nanostructure is derived from biochar, an inexpensive and ubiquitous plant byproduct. The open-up nanoflake structure with sharp edges can induce the fast charge collection and separation. DFT calculations and experimental characterizations are conducted to fundamentally understand the enhanced intrinsic photocatalytic activity of the as-prepared CMCN photocatalysts, especially the role of Co atoms. The delocalized charge density of CMCN could be rational tailored via the increasing density of state and the difference in work functions between g-C3N4 and Co-Mo2C. The electron density of Mo 3d in CMCN is increased through integrating it with Co atoms, which possess numerous delocalized electrons. Compared with the Mo2C/g-C3N4 (MCN) bulk, the CMCN catalyst displays superior photocatalytic activity for the typical PPCPs degradation, mainly arising from the multifaceted open-up surfaces of Co-Mo2C nanoflower, the higher density of electron and more efficient charge transfer ability, as well as the prolonged life time of photogenerated charge carriers. This work provides a cheap and mild route for synthesizing Co-doped Mo2C nanoflower catalyst and expands the scope of constructing high active g-C3N4 based heterostructure.

Automated summary

Researchers developed a flower-like Co-Mo2C sphere/g-C3N4 heterostructure photocatalyst derived from biochar for the degradation of pharmaceuticals and personal care products (PPCPs). The sharp-edged open-up nanoflake structure allowed for fast charge collection and separation. DFT calculations and experimental characterizations revealed the enhanced intrinsic photocatalytic activity of the catalysts, particularly the role of Co atoms. The Co-Mo2C nanoflower catalyst displayed superior photocatalytic activity compared to the Mo2C/g-C3N4 bulk due to its multifaceted open-up surfaces, higher electron density, more efficient charge transfer ability, and prolonged lifetime of photogenerated charge carriers.