Solar Based Photocatalytic Decolorization of Four Commercial Reactive Dyes Utilizing Bound TiO₂-Fe₃O₄ Nanocomposite

Abstract

Dye effluent is one of the most prominent source of water contamination. This study investigated the solar based photocatalytic decolorization of four commercial reactive dyes, which are Reactive Turquoise Blue G 133, Reactive Yellow M4g, Reactive Bordeaux B, on three kind of binders as the support, specifically cyanoacrylate glue, oil-based paint, and white Portland cement on PVC plate. TiO2-Fe3O4 was synthesized using sol-gel method and placed in muffle furnace at 773 K. The composite of TiO2-Fe3O4 was characterized using SEM-EDX and XRD. White cement emerged as the best binder in term of the color removal efficiency of all four dyes compared to other binders, which were more than 90% color removal after 3 h of solar irradiation. Moreover, there was significant enhancement on color removal using immobilized photocatalyst on white cement compared to mobile photocatalyst. The kinetic of the decolorization performance followed the pseudo-firstorder reaction. The apparent reaction rate constant was found to decrease along with the increase of the dye concentration. The photodecolorization kinetics fitted the Langmuir-Hinshelwood model. These protocols and results can be applied into textile industrial primary wastewater treatment using solar as a sustainable light and energy source. ABSTRAKLimbah pewarna cair merupakan salah satu sumber kontaminasi air yang utama. Penelitian ini menginvestigasi proses dekolorisasi empat pewarna reaktif komersial, yakni Reactive Turquoise Blue G 133, Reactive Yellow M4g, Reactive Bordeaux B, dan Reactive Red M8b berbasis reaksi fotokatalisis TiO2-Fe3O4 terimobilisasi oleh tiga pengikat, lem sianoakrilat, cat minyak, dan semen putih, menggunakan cahaya matahari pada plat PVC. TiO2-Fe3O4 disintesis dengan metode sol-gel dan dipanaskan di furnace pada suhu 773 K. Setelah itu, komposit TiO2-Fe3O4 dikarakterisasi dengan analisis SEM-EDX dan XRD. Hasil menunjukkan bahwa semen putih bertindak sebagai pengikat terbaik yang berhasil memberikan nilai efisiensi dekolorisasi paling tinggi untuk keempat warna, yakni diatas 90% dekolorisasi setelah 3 jam penyinaran matahari. Bahkan, ada peningkatan efisiensi dekolorisasi yang signifikan untuk fotokatalis yang difiksasi pada semen putih dibanding fotokatalis bebas. Kinetika dekolorisasi mengikuti reaksi orde pseudo satu. Nilai konstanta laju reaksi semu didapatkan menurun seiring kenaikan konsentrasi pewarna yang diujikan. Kinetika fotodekolorisasi sesuai dengan mode Langmuir-Hinshelwood. Protokol dan hasil didapat mampu diaplikasikan untuk pengelolaan limbah cair primer industri tekstil dengan menggunakan matahari sebagai sumber cahaya dan energi terbarukan. Kata Kunci: dekolorisasi; energi matahari; fotokatalis TiO2-Fe3O4; pewarna reaktif

Optimized Synthesis Temperature and Time to Obtain Crystalline Carbon Nitride with Enhanced Photocatalytic Activity for Phenol Degradation

“…However, owing to the large portion of visible light in the sunray, the development of visible light active photocatalysts has been an important task in the photocatalysis field. Since TiO 2 does not absorb visible light, some modifications are required, such as by doping or making a composite with another visible lightactive semiconductor [5][6][7]. In addition to these efforts, studies on the potential materials that are visible light active are still highly required.…”