Improvement of the Efficiency of TiO2 Photocatalysts with Natural Dye Sensitizers Anthocyanin for the Degradation of Methylene Blue: Review

Abstract

One of the potential methods utilized for dye degradation is photocatalitic, due to its low cost, highly effective, and environmentally friendly. Effectivenes of TiO2 photocatalysts can be enhanced by adding a dye sensitizer. Dye-sensitizer material absorbs visible light to facilitate electron excitation process. Addition of dye-sensitizer on TiO2 photocatalyst promotes it to be more responsive to visible light. Natural anthocyanin dyes are often used as sensitizers of TiO2 semiconductors. Anthocyanins are, usually in the purple to the red color range, a group of natural dyes found in the flowers, leaves, and fruit of plants. The essential principles of dye sensitization to TiO2 have been explored in this review. It is feasible to reduce the band gap energy in the TiO2 photocatalyst by modifying it using a natural dye sensitized modification. Dye sensitizers on TiO2 nanotubes plate have the potential to be employed in a dye degradation photocatalytic system

The Addition of Anthocyanin as a Sensitizer for TiO2 Nanotubes in a Combined Process of Electrocoagulation and Photocatalysis for Methylene Blue Removal

“…The natural dyes are harmless, abundant, and inexpensive and contain a hydroxyl carbonyl group to attach to the surface of TiO 2 [34,35]. Anthocyanin, carotenoid, chlorophyll, curcumin, and flavonoid are natural dyes that can be used as sensitizers [31,[36][37][38][39]. Anthocyanin is a stable sensitizer that can absorb visible light with a high absorption coefficient.…”

Synthesize Fe₃O₄-TiO₂Composite for Methyl Orange Photocatalytic Degradation

“…Most of the textile industry uses synthetic dyes for reasons of cheap, durable, easy to obtain, and easy to use. The use of synthetic textile dyes poses some problems are the waste is still colored and difficult to degrade [1,2,3] . One of the dyes that are widely used in the dyeing process is methyl orange [4,5] .…”

“…The following are some types of TiO2 nanocomposites, namely modification with charge transfer catalyst (Al2O3 and SiO2), coating with photosensitizing dyes [3,14] , noble metal deposition (Fe, Ag, Au, Pt), doping and grafting (CNT and MWCNT), coupling with semiconductors (semiconductor) CdS, ZnO, WO3), and modification with polymers (Poly amide, poly-lactic acid, polypyrrole) [15] . To reduce the loss of catalysts and maintain performance during the separation and recycling process is by adding magnetic properties to the catalyst.…”