Construction of S‐Scheme Alkalized C3N4/ZnO Piezo‐Photocatalyst with Improved Degradation Activity

Abstract The construction of heterojunctions is often considered an effective strategy for achieving visible light driven photocatalytic degradation of organic pollutants. In this work, defective g‐C 3 N 4 ultrathin nanosheets were synthesized via alkaline etching method. Subsequently, a S‐scheme heterojunction was constructed between the contact interface of ZnO nanorods and alkaline C 3 N 4 (aC 3 N 4 ) to promote the electron transfer, resulting in a novel piezo‐photocatalyst (aC 3 N 4 /ZnO). The piezo‐photocatalytic performance of aC 3 N 4 /ZnO samples with different ratios was studied by adjusting the addition amount aC 3 N 4. In addition, optimum 7 %‐aC 3 N 4 /ZnO samples exhibited the highest piezo‐photocatalytic degradation activity under light and ultrasonic irradiation with MB as the target pollutant, exhibiting the 99.89 % degradation rate and 65.68 % mineralization rate within 50 minutes. The capture experiments showed that 1 O 2 ,⋅O 2 − and ⋅OH were active substances in promoting the performance of piezo‐photocatalysis. The mechanism studies indicated that the enhanced piezo‐photocatalytic activity can be attributed to the synergistic effect of the piezoelectric properties of ZnO and the S‐scheme heterojunction formed at the aC 3 N 4 /ZnO interfaces, which provides power for the separation and transport of electron and hole. This work highlights the importance of carefully construction S‐scheme heterojunction and defective structures to precisely understand the catalytic properties, benefiting catalytic design and development.