Publication: Performance evaluation and optimization of anatase/rutile tio2 heterojunction-polyvinyl alcohol-cork composite for methylene blue photodegradation
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Date
2025-09-01
Authors
Ir. Sathu Pillay A/L, Govindasamy
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Abstract
Methylene blue (MB) is a persistent dye pollutant, while titanium dioxide (TiO₂)
photocatalysis remains limited by charge recombination, weak visible-light response, and
agglomeration. The use of natural supports such as cork in TiO₂ composites is
underexplored, and most studies lack systematic optimization, restricting practical
application. This study developed an anatase/rutile TiO₂–polyvinyl alcohol (PVA)–cork
floating composite. TiO₂ powder was synthesized via sol–gel method. and was,
immobilized on a PVA–cork matrix. Characterization was done using XRD,
FESEM/EDS, zeta potential, PL, AFM, UV–Vis, and TOC techniques. The anatase/rutile
TiO2 heterojunction structure enhanced charge separation and reduced agglomeration.
Photocatalytic testing showed higher MB degradation for the heterojunction than for pure
anatase or rutile. In the evaluation phase, the A2R1 composite was identified as the best
performer and subsequently used in the optimization phase. Response Surface
Methodology (RSM) and Box–Behnken Design (BBD) confirmed catalyst dosage, dye
concentration, and cork composite number as significant factors. The best condition (5
ppm MB, 150 mg catalyst, 5 cork composites) achieved the highest efficiency with close
agreement between model and experiment. The optimized composite was stable,
recoverable, and reduced carbon leaching, offering a low-cost, bio-based solution for dye polluted wastewater. The study contributes by introducing cork as a sustainable support,
validating anatase/rutile heterojunctions for visible-light activity, and demonstrating
systematic optimization for scalable wastewater treatment.