Carbon-based materials are widely used for environmental remediation because of their unique and excellent performances. Because of the huge daily consumption of such materials, the economic and environmental friendly derivations from natural biomass are highly desired. Herein, a new biocarbon composite, carbonized loofah/tin(IV) sulfide (CLF@SnS2) foam, was successfully prepared using loofah biofoam through an efficient and scalable method. The hierarchical CLF@SnS2 foam has a high-porous structure, which can provide channels for light traveling through the whole material. It is confirmed that such three-dimensional photocatalytic material can quickly purify Cr(VI)-containing wastewater under mild visible light irradiation, with a efficiency of 99.7% Cr(VI) reduction within 120 min. By contrast, CLF@SnS2 showed much better visible photocatalytic capacity than the uncarbonized counterpart (UCLF@SnS2), because the photoelectrons produced by the SnS2 nanosheets can be rapidly exported by the continuous channels provided by the carbon shell. Besides the high visible light-driven photocatalytic activity, CLF@SnS2 also exhibits excellent cycling stability. More importantly, this study demonstrated that CLF@SnS2 can be used for practical applications due to its flexibility and economic availability.