Effective removal of antineoplastic doxorubicin by 0D Nb2O5 quantum dots embed 3D porous C-doped g-C3N4: Degradation mechanism, pathway and toxicity assessment

The exploitation of an efficient way to treat antineoplastic doxorubicin hydrochloride (DOX) is critical due to its harmful effects on the ecological system and human health. Recently, photocatalysis has emerged as one of the most feasible strategies to resolve this crisis. However, the development of novel catalysts with highly efficient photocatalytic activity still remains a great challenge. Herein, a novel 0D/3D Nb2O5 QDs/C-doped g-C3N4 type-II heterojunction with outstanding adsorption and photocatalytic degradation capacities for DOX was developed based on combining elemental doping, morphological design and heterojunction fabrication. The C-doping significantly promotes the visible light response and charge migration of g-C3N4, thus benefiting to the removal of DOX. Meanwhile, the 0D/3D heterogeneous morphology endows the catalysts with abundant active sites, high adsorptive capacity, favourable structural stability, high surface area and enhanced charge migration, which all contribute to the excellent adsorption and photocatalytic performance. The superoxide radicals shown a prominent role in the photocatalytic reaction. In addition, the Toxicity Estimation Software Tool, liquid chromatography-mass spectrometry and density functional theory calculations were also employed to investigate the DOX degradation mechanism, possible pathways and corresponding toxicity of intermediates. This work provides a promising way to develop highly efficient catalysts for the degradation of DOX.