fig5

Figure 5. (A) PL curve of pure UCNPs when excited by a laser of 980 nm; (B) PL emission spectra of V_Zn-ZIS, UCNPs, and UCNPs@V_Zn-ZIS under the excitation of 350 nm; (C) PL decay curves of V_Zn-ZIS, UCNPs and UCNPs@V_Zn-ZIS; LSCM images of V_Zn-ZIS (D) and UCNPs@V_Zn-ZIS (E); (F) SPV spectra of V_Zn-ZIS, UCNPs and UCNPs@V_Zn-ZIS; Transient photocurrent (G) and EIS Nyquist plots (H) of V_Zn-ZIS, UCNPs and UCNPs@V_Zn-ZIS. PL: Photoluminescence; UCNPs: up-conversion nanoparticles; V_Zn-ZIS: Zn vacancy-rich ZnIn₂S₄; LSCM: laser scanning confocal microscopy; SPV: surface photovoltage; EIS: electrochemical impedance spectroscopy.