Construction of Er3+-activated BiOCl upconverting microplates with boosted visible-near-infrared light driven photocatalytic activity for tetracycline degradation

Photocatalysis based on semiconductor has drawn considerable attention, while the efficient utilization of sunlight is still a challenging. Herein, a series of Er 3+ -activated BiOCl microplates are designed to realize visible-near-infrared light driven photocatalysts. The electronic structure of BiOCl is analyzed by first-principles density functional theory. Excited at 980 nm, the upconversion (UC) luminescence properties of final products are investigated, in which the quenched UC emission is observed when Er 3+ content is 10 mol% and the corresponding mechanism is decided by quadrupole-quadrupole interaction. Moreover, the pump power dependent UC emission spectra are also recorded to explore the UC emission mechanism. Furthermore, excited by different lights ( i.e ., visible and near-infrared (NIR) light), photocatalytic activities of resultant microplates were studied by investigating tetracycline (TC) degradation. Compared with BiOCl microplates, improved photocatalytic activities are observed in Er 3+ -activated BiOCl microplates due to the enhanced separation of photogenerated electron-hole pairs and the specific UC emissions of Er 3+ . Notably, the final compounds doped with Er 3+ can decompose TC irradiated by NIR light. The visible-NIR light triggered photocatalytic mechanism has been systematically discussed and it is contributed by h + , ·OH and ·O 2 - . Ultimately, the TC solution treated with designed microplates exhibits nontoxic to plants. Thereby, our findings suggest that a reusable and efficient photocatalyst can be developed by simultaneously applying UC emission and doping engineering. • Based on the results of fist-principles DFT, one knows that BiOCl is an indirect semiconductor. • BiOCl: x Er 3+ microplates have good UC emission behaviors and the optimal state is gained at x = 0.01. • Upon visible-NIR light irradiation, BiOCl: x Er 3+ microplates can degrade TC efficiently. • Compared with BiOCl, BiOCl: x Er 3+ microplates possess superior photocatalytic activity. • h + and ·O 2 - take the main role in determining the visible-NIR triggered photocatalytic mechanism.