S vacancies and heterojunction modulated MoS2/C@Fe3O4 towards improved full-spectrum photo-Fenton catalysis: Enhanced interfacial charge transfer and NIR absorption

Fe3O4-based core-shell/heterojunction composites exhibit favorable photothermal catalytic performance in environmental remediation, but limited by the weak interface electron transport efficiency and poor near infrared (NIR) absorption capacity. Herein, Sv-MoS2/C@Fe3O4 core-shell composites were prepared for the first time by coating S vacancies-bearing MoS2 (Sv-MoS2) on the surface of carbon-decorated Fe3O4 microspheres (C@Fe3O4) derived from copper slag-based polymer microspheres and was used as photothermal catalyst to activate H2O2 towards chlortethromycin hydrochloride (CTC) elimination from wastewater. By virtue of the synergistic effect of the petal-like Sv-MoS2, carbon-decorated layer and multi light reflection in porous microspheres, Sv-MoS2/C@Fe3O4 exhibited excellent full spectrum absorption and carrier migration efficiency, with catalytic activity of 0.149 min(-1) and H2O2 utilization rate of 93.6 %. The degradation rate is 3.9 and 3.1 times of C@Fe3O4 and MoS2/C@Fe3O4 under full light irradiation which can heat the solution from room temperature to 72.4 degrees C. This excellent catalytic performance is mainly originated from that the S-type heterostructure promotes the charge separation, transfer and redox ability, and enhances catalytic oxidation by regulating electron density of the interfacial carbon and reducing the energy barrier of H2O2 activation through S vacancies. Moreover, the decorated carbon layer can serve as a hot core to provide heat to Sv-MoS2 and enhance the collision chance of photogenerated carriers, thus improving the catalytic performance of Sv-MoS2/C@Fe3O4. This work provides new strategies for constructing heterojunction materials with fast electron transport efficiency and using solar energy for environmental remediation.