Handling of petrochemical waste oil (PWO) is costly, tedious, and risky to human health and environment. Hence, upcycling of PWO for biomass conversion to platform chemicals would be very advantageous. Herein, a highly porous sheet-like structure of sulfonated graphene oxide (sGO) catalyst was synthesized from PWO. The synthesized sGO possessed high surface area (246.2 m(2) g(1)) due to its mesoporosity and high content of sulfonic groups (2.4 mmol g(-1)) grafted onto its surface. As its application, the synthesized sGO was employed to convert fructose to levulinic acid (LA) within deionized water. The high yield (61.2 mol %) of LA was obtained under a condition of 160 degrees C, 1 h, and 6 g g(-1) fructose to sGO weight ratio. It can be reused several times (5 runs) with no severe degradation of catalytic activity. Therefore, the sGO derived from petrochemical waste oil would be considered as an environmentally benign catalyst for producing platform chemicals, i.e. LA from fructose and other biomass derivatives.