Pd decorated MoS2 nanoflowers as photothermal catalyst for enhanced NIR-induced 4-nitrophenol reduction

Abstract

Photothermal catalysis has aroused increasing interests due to its huge potential in environmental purification, and the key is to develop efficient photothermal catalytic materials. In this work, 4-nitrophenol (4-NP) is chosen as the probe molecule of nitroaromatics. A Pd/MoS2 catalyst prepared by two-step hydrothermal method has been identified as a highly active and stable catalyst in the photothermal catalytic reduction of 4-NP. Besides, Pd/MoS2 nanoflowers have wide-range photo-absorption between 200 and 1100 nm and high photothermal conversion efficiency of 43 %. Under the irradiation of 808 nm laser, Pd/MoS2 nanoflowers showed a 6-fold reduction rate for 4-NP compared to MoS2 nanoflowers. Intriguingly, Pd/MoS2 catalyst exhibited higher activities under photothermal heating than that under oil bath heating with the same reaction temperature. Additionally, the Pd/MoS2 nanoflowers could show high and stable 4-NP reduction rate with slight morphology change after 7 cycling reaction tests, implying excellent recyclability. These results demonstrate that Pd/MoS2 nanoflowers and photothermal catalysis offer new opportunities for the catalytic elimination of organic pollutants from water.