Congo red dye removal from wastewater using TiO₂ nanorod-coated river sand under visible light

Coloring dyes are the major sources of water pollution. Degradation of dye from wastewater using nanomaterials is-a well-known process, but the separation of nanoparticles from treated water is costly. In this study, a cost-effective dye degradation process followed by easy separation of the nanoparticles from treated water is proposed. River sand is Earth’s most abundant naturally occurring crystal. River sand is used as a substrate to grow a TiO₂ nanorod array. The hydrothermal process is used to grow a homogeneously distributed TiO₂ nanorod array on river sand. An optical bandgap (2.8 eV) of synthesized material is achieved. Photocatalytic degradation study is performed under visible light against Congo red colouring dye. The synthesized material is characterized by FESEM, XRD, FTIR and UV-Vis. Good crystallinity of the sample is observed. The addition of TiO₂ nanorod-coated sand particles in the polluted water before the photocatalytic process and separation of the same from the treated water is easy. The synthesized TiO₂ nanorod-coated sand particles have 88.59% efficiency for the photodegradation of Congo red colouring dye from wastewater under visible-light.