Enhancing the photocatalytic performance of the g-C3N4/BiOCl heterojunction in gaseous toluene degradation via K+ decoration in g-C3N4

Doping or constructing heterojunctions by coupling with other semiconductors are effective methods to improve the photocatalytic performance of graphitic carbon nitride (g-C3N4) in toluene degradation. Herein, thermally condensed synthesized K-doped g-C3N4 (KCN) is coupled with BiOCl via a hydrothermal method, and KCN/BOC heterostructures are obtained. The optimal KCN1/BOC heterojunction exhibits approximately 85% removal of toluene after 150 min irradiation under simulated solar light, which is 12.4 and 9.6 times higher than those of g-C3N4 and BiOCl, respectively. The superior performance of KOH-modified g-C3N4 is attributed to the electron transfer channels formed by the insertion of K+ into the g-C3N4 layers, which facilitate efficient charge separation and rapid electron transfer. Furthermore, the KCN/BOC heterostructure with the Z-scheme further improves the surface charge separation efficiency, which plays a critical role in the photocatalytic process. This work provides a facile and promising strategy for dual-strategy modification of g-C3N4 to enhance photocatalytic degradation activity.