0D/2D plasmonic Cu2-xS/g-C3N4 nanosheets harnessing UV-vis-NIR broad spectrum for photocatalytic degradation of antibiotic pollutant

Localized surface plasmon resonances (LSPRs) are usually achieved by some small grains of noble metal (Au, Ag et al.) to enhances the light absorption and charge carrier’s concentration of photocatalysts, but the wide application of noble metals is limited by their high cost. Here, we report the preparation of 0D/2D plasmonic Cu2-xS/g-C3N4 nanosheets (CSCNNs) and the utilization of LSPRs generated from Cu2-xS nanodots instead of noble metals to improve the photocatalytic activity for degradation of typical antibiotic levofloxacin (LVX). One-step hydrothermal method was employed to grow the highly dispersed Cu2-xS nanodots on the g-C3N4 nanosheets. Various characterization techniques verify the strong light absorption capacity and longer carriers’ lifetime for CSCNNs. The analysis of band structure reveals the efficient separation and transmission mechanism of photogenerated electrons and holes. More importantly, LSPRs has been proved to be effective in increasing the light absorption in near infrared (NIR) region and the theoretical finite difference time domain (FDTD) simulations demonstrated that Cu2-xS LSPR-induced electromagnetic field in g-C3N4 nanosheets was far stronger than that of Ag and Au in NIR region. Consequently, efficient photocatalytic degradation of LVX under full solar spectrum (UV–vis-NIR) can be achieved for CSCNNs. This work will lead to a cheap and efficient LSPR photocatalysis system for treatment of antibiotic wastewater or other photocatalytic applications.