Biomass porous carbon as the active site to enhance photodegradation of oxytetracycline on mesoporous g-C3N4

Graphitic carbon nitride (g-C3N4) is widely used in photocatalytic adsorption and degradation of pollutants, but there are still some problems such as low adsorption performance and high electron-hole recombination efficiency. Herein, we propose a new molten salt assisted thermal polycondensation strategy to synthesize biomass porous carbon (BPC) loaded on g-C3N4 composites (designated as BPC/g-C3N4) with a hollow tubular structure, which had a high surface area and low electron-hole recombination rate. The study shows that the morphology of g-C3N4 changes dramatically from massive to hollow tubular by molten salt assisted thermal polycondensation, which provides a base for the loading of BPC, to construct a highly effective composite photocatalyst. BPC loaded on g-C3N4 could be used as the active site to enhance Oxytetracycline (OTC) removal efficiency by adsorption and with higher electron-hole separation efficiency. As a result, the BPC(5%)/g-C3N4 sample presented the highest photocatalytic degradation efficiency (84%) for OTC degradation under visible light irradiation. The adsorption capacity and photocatalytic reaction rate were 3.67 and 5.63 times higher than that of the g-C3N4, respectively. This work provided a new insight for the design of novel composite photocatalysts with high adsorption and photocatalytic performance for the removal of antibiotic pollutants from wastewater.

Automated summary

In this study, a new approach was proposed to synthesize biomass porous carbon loaded on graphitic carbon nitride composites with a hollow tubular structure. The composites exhibited high surface area and low electron-hole recombination rate, leading to enhanced removal efficiency of oxytetracycline through adsorption and efficient electron-hole separation. The results showed that the composite material demonstrated higher photocatalytic degradation efficiency under visible light irradiation, with adsorption capacity and photocatalytic reaction rate 3.67 and 5.63 times higher than that of pure graphitic carbon nitride, respectively.