Constructing String-Cage Structure of α-MnO2@CoS2 Photoelectrocatalyst for Efficient Detoxification Sulfonamides Wastewater
Hongchao Ma, Yan Chen, Huizhen Jin, Xinyue Wang, Guowen Wang, Yinghuan Fu, Pengyuan Wang, Vadivel Subramaniam, K. Ramachandran, Xinghui Liu
Abstract
Constructing high-efficiency heterostructured photocatalysts for antibiotic degradation is critical and challenging. Herein, a “pearl necklace” α-MnO2@CoS2 photoelectrode was prepared via a continuous hydrothermal process. The as-obtained photoelectrode comprised overlong α-MnO2 nanowires (as leading wire) and CoS2 nanocages (as decorations) derived from ZIF-67 precursor. The contrivable α-MnO2@CoS2 photoelectrode exhibited lower charge transfer resistance and higher carrier separation efficiency than single α-MnO2. The α-MnO2@CoS2 provided a heterostructured interface with fast carrier transfer, where α-MnO2 nanowire played the carrier transfer channel, and the CoS2 “nanocages” can effectively increase the contact area between the catalyst and the pollutants. Meanwhile, the stable p-n junction with the internal electric field can be formed in the synthesized α-MnO2@CoS2 composite to avoid the destruction of heterogeneous junctions and thus maintain stability. As a result, the α[email protected] had the highest PEC efficiency with a degradation rate of 98.95% for sulfonamides (SMX) within 50 min among prepared catalysts. The charge density difference of α-MnO2@CoS2 was performed to investigate the strong interaction between α-MnO2 and CoS2. This study provides insights into the construction of nanomaterial structures and their applicability to photocatalytic degradation of target pollutants, which can be expanded for future cost-effective water purification applications.