OICC Press Iranian Journal of Catalysis 2345-4865 14 4 2024 10 08 Anatase- Brookite Mixed Phase Tio2 Nanoparticles for The Photocatalytic Degradation of Methylene Blue 1 17 10.57647/j.ijc.2024.1404.40 EN M S MONISHA Nanophotonics Laboratory, Department of Physics, Mar Ivanios College (Autonomous), Thiruvananthapuram, Kerala, India https://orcid.org/0009-0005-0119-7436 Rajeswari Sreeja Nanophotonics Laboratory, Department of Physics, Mar Ivanios College (Autonomous), Thiruvananthapuram, Kerala, India https://orcid.org/0000-0002-2327-0682 Journal Article 2024 10 08 Herein, we report visible light active, efficient, simple, bi-phasic photocatalyst composed of anatase-brookite mixed phase, crystalline TiO2 nanoparticles synthesized through a simple sol-gel approach. The physicochemical characteristics of the nanoparticles were established through characterization tools such as XRD, FESEM, EDS, TEM, DRS, FT-IR, XPS, Raman, PL, and TGA.  Visible light-driven degradation of methylene blue (MB) dye was observed, which was confirmed through the improvement in the rate constant compared to that in UV exposure. This can be attributed to the prolonged charge separation resulting from the anatase-brookite junction effect. The free radicals generated (superoxide anions and hydroxyl radicals) after the incidence of light are responsible for the photocatalytic degradation of the MB, whose influence was validated through the scavenger method. The generation of degradation intermediates were verified through LC-MS-MS analysis. The nanoparticles showed maximum photocatalytic performance in the basic pH conditions. The recyclability of the photocatalyst was also established. The enhanced activity resulting from the combined effect of anatase-brookite phases of TiO2 in the nanoformulation will enable its potential use as a vital, visible light active, eco-friendly bi-phasic photo catalyst offering low-cost environment remediation in a short period of time using the minimum quantity of photocatalyst.  Research Highlights Sol gel derived, nano sized, visible light active, recyclable, anatase- brookite bi-phasic TiO2 photocatalyst Enhanced activity resulting from brookite-anatase junction effect Visible light driven photocatalytic decomposition of Methylene Blue dye Highest photocatalytic performance in the basic pH condition Low-cost environment remediation in a short period of time using minimum quantity of photocatalyst.