Photocatalytic Degradation of Lignin Model Compounds Using 2D-MoO₃/Noble Metal Nanoparticles Hybrid Nanostructures

Hybrid nanostructures that consist of two-dimensional nanomaterials and plasmonic nanoparticles have been receiving great interest in the academic and industrial fields. The hybrid nanostructures exhibit unique optical characteristics in combination with the physicochemical properties of 2D nanomaterial and the plasmonic optical effects. Thus, hybrid nanostructures have been widely investigated for optical sensors, solar cells, and electronic devices. In addition, the 2D/plasmonic nanoparticles hybrid nanostructures enable improved photocatalytic performance owing to enhanced charge carrier generation and efficient charge transfer. Lignin, which is a natural bio-polymer, is composed of a number of aromatic rings with diverse functional groups such as carbonyl, hydroxy, and methoxy groups. Therefore, it can be expected that the efficient decomposition of lignin is able to alternate various polymeric materials that came from fossil fuels. In this research, we employed MoO₃/metal nanoparticle hybrid nanostructure to drive photocatalytic degradation of the lignin model compound. We prepared a hybrid nanostructure through the exfoliation of bulk MoO₃ and photoelectrochemical deposition of noble metal nanoparticles such as Au, Ag, Pd, and Pt on the exfoliated MoO₃ nanosheet. Furthermore, we compared the photocatalytic degradation efficiency of the lignin compound with respect to the type of metal nanoparticles and performed a mechanism study of the degradation. The hybrid nanostructures were characterized by UV-Vis spectrophotometer, TEM, and XRD. As well as, qualitative and quantitative analyses for the lignin compound and the products after degradation were carried out using UV-Vis spectrophotometer, HPLC, and NMR.