Generating a captivating S-scheme CuBi2O4/CoV2O6 heterojunction with boosted charge spatial separation for efficiently removing tetracycline antibiotic from wastewater

In this work, a captivating S-scheme CuBi2O4/CoV2O6 heterojunction was innovatively constructed by in situ growing CoV2O6 nanoparticles on the surface of CuBi2O4 microrods. Of note, the unique CuBi2O4 microrods served as an outstanding substrate to achieve the uniform loading of CoV2O6 nanoparticles. Compared with neat CoV2O6 and CuBi2O4, as expected, the resulting CuBi2O4/CoV2O6 illustrated significantly boosted photocatalytic efficiency for degrading tetracycline (TC) under visible light illumination. More impressively, the optimized CuBi2O4(30 wt%)/CoV2O6 manifested the best TC removal rate of 0.01328 min−1 after 120 min of reaction, which was roughly 33.2 and 14.4 times larger than those of neat CoV2O6 and CuBi2O4, separately. Such an exceptional photocatalytic activity was mainly ascribed to the expedited the charge spatial detachment and transport, and synchronously reserved the strong redox ability driven by the established S-scheme heterojunction between CoV2O6 and CuBi2O4. Moreover, the reactive species scavenging tests and electron spin resonance analysis substantiated that the superoxide radicals combined with photogenerated holes were unquestionably responsible for removing TC. Eventually, the possible degradation mechanism and pathways of TC over CuBi2O4/CoV2O6 were also put forward.