Employing Cu(II) complexes of N,O-donor ligand for catalysis in visible light driven cleavage of lignin C-C bonds

•Novel synthesis of Cu(II) Schiff base complexes was reported as photo-catalysts.•The photo- catalysts was characterized by using single crystal XRD, FTIR, LCMS and PXRD.•Photo-catalytic cleavage of lignin model substrates was observed.•Mechanistic study on cleavage reaction of lignin model was performed by UV-Vis, ESI-MS, NMR and DFT.•Photo-catalytic degradation of authentic lignin (extracted by pineapple stem) was investigated.