- Thesis topic: The Application of Composite Catalysts Synthesized by Microwave Plasma on Photocatalytic Degradation of Acid Blue

- Doi: https://doi.org/10.6840/cycu202200089

- Abstract: 

      Acid Blue, which is categorized as Azo Dye producing a high rate of wastewater and treated conventionally with coagulation-flocculation, biological treatment, and adsorption, needs a huge amount of space. TiO2 is a widely used photocatalyst, it has several advantages, including its suitability for small area applications, low visible light response, and rapid recombination of e/h+ pairs. By combining biochar with TiO2 nanoparticles, these limitations can be overcome. The photocatalytic activity of the biochar-supported TiO2 composites was significantly increased in the UV-visible range. Biochar and Co-Pyrolysis char gained from plasma pyrolysis by-product as photocatalysts doped with Titanium (II) to treat Acid Blue dye. The synthesis applied with hydrolysis method following with calcination process to dop Biochar and TiO2 as photocatalysts material. The ratio between Biochar and Co-Pyrolysis char in 7L/m, 9 L/m, and 11L/m plasma pyrolysis by-product over TiO2 was varied by 0.1:1; 0.3:1; 0.3:1; 0.5:1; 0.7:1; and 1:1. Characterizations using FTIR, XRD, BET, Elemental, and Zeta Potential were carried out, and removal behavior was analyzed with pseudo-first-order, pseudo-second-order, Langmuir kinetic, and isotherm photocatalysts model. The benefit of using Biochar and Co-Pyrolysis char/TiO2 compared with TIO2 and pure Biochar alone is it react faster, degrade the pollutant up to 83.60% of Biochar/TiO2 9L/m 1/1 in 10 PPM Acid blue dye with minimum side effect due to the process of photodegradation and demineralization which react The Co-pyrolysis char/TiO2 composite has 78.80% TiO2 9L/m 1/1 photodegradation and 20.15 nm of particle size. On photocatalysts, surface area after synthesis process of Biochar/TiO2 and Co-pyrolysis char/TiO2 respectively are 119.4356 m2 and 88.2361 m2. While pore volumes of both materials respectively are 0.7421 m3 and 0.1682 m3. Functional groups of Biochar/TiO2 samples which appeared are –OH (hydroxyl group), C=C, -CF, C=O, CH3, C–O–C bond, while, at Co-Pyrolysis Char which appeared are OH, C=C, -CF. Physical and chemical influences were proven by kinetic analysis with pseudo-first-order kinetic. Acid blue molecules are adsorbed primarily via their sulfonate groups when TiO2 is added to dye solutions. The primary degradation pathway investigating naphthyl azo dye photodegradation in AOP systems is the attack of hydroxyl radicals on the naphthalene ring, resulting in the formation of a hydroxylated naphthyl azo dye that is then cleaved. Additionally, hydroxyl radicals attack aromatic rings containing azo groups, resulting in the cleavage of azo bonds. Both of these reactions result in the destruction of chromophoric groups. Multiple usages of photocatalysts material will cause performance at 10 PPM Acid blue dye in the 3rd cycle usage decline by 64.63% and 61.38% of Biochar/TiO2 and Co-pyrolysis char/TiO2 correspondingly.

Keywords: Biochar, Co-pyrolysis char, Photocatalyst, Titanium Dioxide, Acid Blue