Broad spectrum driven Y doped BiO 2-x for enhanced degradation of tetracycline: Synergy between singlet oxygen and free radicals

The synergy of singlet oxygen and free radicals is crucial to driving organic pollutant degradation in water contain complex natural organic matter. In this study, the rare earth element yttrium doped bismuth oxide (YBiO2_ x) photocatalyst was prepared by a hydrothermal method. Y doped BiO2_x enables produce oxygen vacancies and possess up-conversion property. The superoxide radicals (center dot O2_ ), singlet oxygen (1O2), hydroxyl radicals (center dot OH) and hole (h+) play a crucial role in photocatalytic reaction process. The increased 1O2 and hydrogen peroxide are mainly originated from center dot O2_ . The degradation efficiency of tetracycline (TC) reached 70.45 % and 40.17 % under Vis and NIR light, respectively. Notably, the TC removal efficiency of Y-BiO2_x maintained 65.92 % in the actual wastewater containing various anions and humic acid (HA), which originate from synergy of singlet oxygen and free radicals. This study provides a new strategy for synergistic singlet oxygen and free radicals to degradation of organic pollutants in complex water matrix.

Automated summary

This study demonstrates the importance of the synergy between singlet oxygen and free radicals in driving the degradation of organic pollutants in water. The YBiO2_ x photocatalyst, prepared through a hydrothermal method with yttrium doping, is found to produce oxygen vacancies and possess up-conversion property. Superoxide radicals, singlet oxygen, hydroxyl radicals, and holes play crucial roles in the photocatalytic reaction process. The study also reveals that the degradation efficiency of tetracycline can be maintained in the presence of various anions and humic acid in wastewater, thanks to the synergy between singlet oxygen and free radicals.