Preparation of g-C₃N₄ nanosheets photoelectrode and its photoelectrocatalytic activity for tetracycline degradation

Abstract

g-C3N4 nanosheets photoelectrode was prepared by a facile drop coating method. The influences of precursor materials and bias voltages on the photoelectrocatalytic properties towards tetracycline degradation using as-prepared g-C3N4 nanosheets photoelectrode (DUCN) were studied. The results demonstrate that the DUCN photoelectrode prepared by calcination of urea and dicyandiamide precursor mixtures exhibits the highest pollutant removal efficiency, which may be due to its best film formation property and highest photoelectron-hole separation efficiency. In addition, in the process of photoelectrocatalysis (PEC), photocatalysis (PC) and electrocatalysis (EC) promote and optimize each other, showing a significant synergistic effect. The DUCN photoelectrode displays the highest removal rate of tetracycline with an initial concentration of 5 mg/L at a bias of 1.0 V, which are 5.6 times and 3.8 times of that obtained by single photocatalytic and electrocatalytic process, respectively. The reason for the enhanced pollutant removal efficiency may be that the external bias voltage enables the photogenerated electrons transfer to the counter electrode more efficiently under the photoelectric synergistic effect, which promotes the separation of photogenerated electrons and holes.

Keywords

• g-c₃n₄
• photocatalysis
• photoelectrocatalysis
• tetracycline