Photocatalytic degradation of Acid Red dye stuff in the presence of activated carbon-TiO2 composite and its kinetic enumeration

•Preparation and characterization of TiO2/activated carbon photo-catalyst.•Photo-catalytic degradation analysis of Acid Red 131 in a photochemical reactor.•Mathematical modeling and kinetics elucidation of the reaction.•Effect of spent catalyst on the seed germination of Vigna radiata.

The present paper deals with photocatalytic degradation of effluents from dye industries which have known toxic impacts on flora and fauna. Nano composite of titanium dioxide having activated carbon (TiO2/AC) base was synthesized using sol-gel method. The synthesized catalyst was then characterized by Fourier Transform-Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and Brunauer Emmet Teller (BET) surface area analyzer. A synthetic solution of AR-131 dye was subjected to photocatalytic degradation using TiO2/AC nano composite as catalyst. The degradation mechanisms of dye (AR-131) via photo-catalysis were found to follow a first order kinetics mechanism (vis. Langmuir- Hinshelwood Model). Toxicity of spent catalysts was further investigated in seed germination of Vigna radiata. Enhanced seed germination along with elongation of root and shoot was noticed up to the concentration of 500 ppm confirming its non toxicity.