Lignocellulosic materials extraction from waste baby diaper to prepare light-responsive metal oxide/carbon composite for efficient organic dye pollutant removal

The bimetal oxide comprising nickel incorporated β-Bi₂O₃ on graphitic carbon in the form of bismuth nickel oxide (BNO@C) was prepared by waste lignocellulosic materials collected from cheap and readily available baby diapers. The prepared BNO@C was used to photocatalytically degrade methylene blue under UV-light irradiation. Prior to the photocatalytic performance analysis, the formation of BNO@C was confirmed by various morphological and structural analysis including SEM, TEM, XRD, and XPS analyses. As a result, the two-dimensional nanosheet morphology and tetragonal primitive lattice-structure with 2+ and 3+ oxidation stated Ni and Bi in BNO@C structural formulation were confirmed. In photocatalysis experimentation examined with BNO@C, the maximum methylene blue removal percentage of 96.7 % was achieved within 16 min. The influence of Ni²⁺ in BNO@C was identified by performing the photocatalytic performance of bare NiO@C and Bi₂O₃@C, yielding maximum dye removal of 32.8 % and 64.5 %, respectively. The efficacy of Ni in BNO@C toward increasing catalytic efficiency was identified using DFT analysis, revealing the acting of Ni as active sites for improved light absorption tendency. These findings show a novel strategy to prepare a low-cost BNO@C catalyst with efficient photocatalytic activity, opening a new path for a cost-efficient wastewater treatment approach.