A composite material (TNB/SC) based on TiO2 nanobelts anchored to carbon particles (SC), and made from soybean husk, was prepared by an alkaline hydrothermal method. Microscopy analysis confirmed the nanobelt morphology of TiO2 and the incorporation of nanobelts onto carbonized soybean husks in the effective formation of a TNB/SC composite. XRD analysis ascertained the formation of the anatase phase in the TNB/SC composite. X-ray fluorescence spectroscopy and elemental analysis defined the 1.2:1 TiO2:carbon ratio. UV-Vis diffuse reflectance spectroscopy assessed lower band-gap energy in the composite than in the similarly prepared TiO2 nanobelts. Fourier transform infrared spectroscopy showed that the functional groups of the carbon are retained in the composite. Nitrogen adsorption isotherms revealed that the hydrothermal conditions served for the activation of the non-porous carbon obtained from soybean husk, thus creating micro and mesopores and increasing the specific surface area value. The photocatalytic activity of the TNB/SC composite was studied by the degradation of an aqueous solution of the dye Basic Yellow 28 (BY28). The photoproducts were monitored and identified using HPLC-DAD and HPLC-ESI-QToF-MS chromatography. The degradation capacity of the TNB is preserved in the TNB/SC composite. Photodegradation and adsorption go hand in hand during the decolorization of the solution since the hydroxylated hydrazono-indolium species, and small molecules formed photocatalytically by the TNB, get adsorbed on the carbonaceous portions of the composite. Thus, we reliably disaffirm synergism reflected as an increase in the composites photoactivity, but rather as the combination of two phenomena for elimination effectiveness. It was demonstrated that the observed total decoloration does not necessarily lead to the mineralization of the dye solution.