Synthesis of Mesoporous Iron Oxide using P123 and Gelatin as Photocatalyst in Methylene Blue Degradation

Department of Chemistry Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret, Surakarta 57126, Indonesia

^* Corresponding author: mariaulfa@staff.uns.ac.id.

Abstract

This study reports the synthesis of mesoporous iron oxide (Fe₂O₃) using Pluronic P123 and gelatin as dual templates and evaluates its performance as a photocatalyst in the degradation of Methylene Blue (MB). The materials were prepared via a hydrothermal sol–gel method followed by calcination at 550 °C and subsequently characterised using XRD, FTIR, BET, SEM-EDX, TEM, and TGA techniques. XRD confirmed the coexistence of α-Fe₂O₃ (hematite) and γ-Fe₂O₃ (maghemite) phases, with sharper diffraction peaks observed in the gelatin-assisted samples, indicating improved crystallinity. FTIR spectra revealed characteristic Fe–O stretching vibrations along with enhanced O–H and H–O–H bands in the gelatin- modified materials, suggesting stronger surface hydroxylation. BET analysis showed a significant enhancement in textural properties, where the Iron-P123–Gelatin sample exhibited a surface area of 16.20 m²/g, pore volume of 0.080 cm³/g, and pore diameter of 13.5 nm, compared to 1.70 m²/g, 0.004 cm³/g, and 3.2 nm, respectively, for Iron-P123.These structural improvements translated into superior photocatalytic performance. Under UV-light irradiation, the Iron-P123–Gelatin catalyst achieved nearly complete degradation of MB within 90 minutes, while the non-gelatin catalyst exhibited only moderate activity. The enhanced activity is attributed to the larger surface area, improved porosity, and higher density of active sites facilitated by the incorporation of gelatin, which promotes more efficient electron–hole separation and reactive species generation. Overall, the results demonstrate that gelatin-assisted synthesis significantly improves the crystallinity, porosity, and surface chemistry of iron oxide photocatalysts, leading to enhanced efficiency in the degradation of organic dyes.