The synergetic removal of Cr(VI) and TC on nZVI/MoS2 composites

The contamination of heavy metals and antibiotics represents one of the most serious environmental issues. In this study, the synergistic removal of chromium (Cr(VI)) and tetracycline (TC) by nZVI/MoS 2 composites was investigated to evaluate the removal performance of nZVI-based composites. The characterizations showed that the addition of MoS 2 increased the dispersion of nZVI, provided multiple electron-rich active sites and facilitated the electron transfer of photocatalysis. The addition of TC significantly enhanced the Cr(VI) removal rate, increasing it from 60 % to 80 % within 10 min. The catalytic reaction rate of nZVI/MoS 2 increased from 0.0046 to 0.0163 min −1 . Furthermore, the presence of Cr(VI) also improved the photodegradation efficiency of TC. Based on XPS and EPR analyses, the synergistic removal of Cr(VI) and TC was mainly attributed to enhanced electron transfer promoted by the presence of TC, which accelerated the photocatalytic reduction of Cr(VI) to Cr(III). Surface complexation modeling further confirmed that Cr(VI) removal by nZVI/MoS 2 involved both adsorption and reduction processes. These results are anticipated to inform the design of more efficient nZVI-based composites for practical applications in environmental remediation.