Li2MnO3 nanoparticles decorated with Co3O4 as functional visible-light-induced heterojunction photocatalysts for the degradation of tetracycline

Abstract

Fabrication of heterojunction nanocomposites as effective photocatalysts with high photocatalytic ability is critical to secure our environment's safety. Herein, a novel approach to creating a stable and effective heterojunction of Li2MnO3/Co3O4 photocatalyst is presented. TEM and XRD analyses indicate that the high crystallinity phase of monoclinic Li2MnO3 and cubic Co3O4 was formed with a uniform shape (10–15 nm). The obtained Li2MnO3/Co3O4 photocatalysts were utilized for the photocatalytic degradation of tetracycline (TC) under visible light. The 12% Li2MnO3/Co3O4 sample achieved a maximal photocatalytic performance of 100% after 105 min, which was two times greater than that of pure Co3O4, and its rate constant was improved to 2.1 times that of Co3O4. The photocatalytic mechanism was verified utilizing the time-resolved photoluminescence (TRPL) spectra, photocurrent density, photoluminescence (PL) spectra, EIS Nyquist plots and Mott-Schottky curves. The enhanced photocatalytic performance of the Li2MnO3/Co3O4 nanocomposites is attributed to the construction of heterojunctions with a synergistic effect, which obstruct electron-hole recombination, extend the light absorption region, and accelerate the separation of carriers. The obtained heterojunction Li2MnO3/Co3O4 photocatalyst was effective and stable after five cycling runs under visible illumination. As a result, this effective, facile, and green strategy provides a new horizon to recognize mesoporous Co3O4-based photocatalysts for photocatalysis applications under visible illumination.