Lignin-derived carbon quantum dots/Ni-MOL heterojunction from red phosphorus-assisted ball milling pretreatment and their application in photocatalysis: An insight from experiment and DFT calculation

The constructing defects by doping phosphorus elements are limited by high energy consumption, environment pollution and long preparation time. In this work, lignin-derived carbon quantum dots/nickel metal-organic layer (Ni-MOL) heterojunction was successfully prepared by red phosphorus-assisted ball milling pretreatment. And the application in photocatalytic tetracycline (TC) degradation have been investigated systematically by the combination of the calculational and experimental methods. The maximum degradation rate was 98.98% for P(1.0)-CD/Ni-MOL in 120 min under visible light condition. P-doping was beneficial to reduce the electron transport resistance. Moreover, it increased the hydrophilicity but reduced the position of conduction band, thus more active center dot O-2(-) for TC degradation were generated. Hence, the novel photocatalyst prepared by the simple and low energy consumption method is expected to treat TC wastewater effectively and this work makes a contribution to the perfection of P-doped photocatalysts.

Automated summary

In this study, lignin-derived carbon quantum dots/nickel metal-organic layer (Ni-MOL) heterojunction was successfully prepared by red phosphorus-assisted ball milling pretreatment. The application of this photocatalyst in photocatalytic degradation of tetracycline (TC) was systematically investigated. It was found that the photocatalyst exhibited high degradation rate and short degradation time under visible light. Phosphorus doping helped to reduce electron transport resistance and increase the activity of the catalyst.