<p>Organic dyes from textile industries, which typically contain a mixture of several dyes have become a serious concern due to their presence in wastewater. Therefore, high performance materials and methods are required to eliminate and analysis them from wastewater. Herein, we fabricated SnO₂/CuNb₂O₆ heterostructure nanocomposite as an efficient visible-light-driven photocatalyst to degrade and mineralize basic violet 16 (BV16) and basic red 46 (BR46) dyes in single or binary solutions. SnO₂ nanotube arrays were successfully synthesized using the liquid phase deposition (LPD) process. Following this, SnO₂ nanotubes were integrated with CuNb₂O₆ nanoparticles prepared via the sol–gel method. The first-order derivative spectrophotometric technique was used to solve the overlapped absorption spectra that occur in simultaneous analysis of dyes for the multi-component systems. The photocatalytic experiments demonstrated that SnO₂/CuNb₂O₆ nanocomposite has the highest photocatalytic activity to degrade BV16 and BR46 dyes in both single and binary mixture solutions, compared to the pure SnO₂ nanotubes and CuNb₂O₆ nanoparticles. For the SnO₂/CuNb₂O₆ nanocomposite, 94.6% of BR46 and 95.1% of BV16 were degraded in their binary mixtures, whereas the degradation efficiency of BV16 and BR46 dyes in their respective single solutions were found to be 94.5% and 97.7%, respectively. It was observed that the degradation rate constants of BR46 for all photocatalysts in single dye solution was lower than that of BV16, which can be ascribed to the relatively more complex structure of BR46 rather than BV16. This study exhibited the feasibility of designing and utilizing SnO₂/CuNb₂O₆ nanocomposites as a promising photocatalytic material for the efficient degradation of dye mixtures in the textile industry.</p> Graphical abstract <p></p>