Nur Ahmad, Jelita Marista Lalus, Ary Mauliva Hada Putri, Triastuti Sulistyaningsih, Khoiriah, Asmida Herawati, Reza Audina Putri
The contamination of aquatic environments by pharmaceutical residues, notably paracetamol (PCT), has emerged as a significant environmental issue, attributed to its persistence and the inadequate efficacy of traditional treatment approaches in its removal. In this study, TiO2/biochar composite photocatalysts were synthesized via an ultrasonic-assisted wet impregnation method and applied for the photocatalytic degradation of PCT under UV light irradiation. Biochar was produced from rice straw biomass waste through a controlled pyrolysis process and subsequently composited with anatase-phase TiO2 at biochar mass ratios of 10, 20, and 30 wt.%. The use of rice straw-derived biochar not only supports agricultural waste valorization but also provides a porous carbon matrix that enhances TiO2 dispersion and surface properties. The photocatalysts were characterized using XRD, FTIR, BET, FESEM-EDX, XPS, PL, and UV-DRS. XRD analysis confirmed the preservation of the anatase TiO2 phase with crystallinity 93.92% and crystallite sizes of 40–50 nm. FTIR spectra revealed characteristic Ti–O–Ti and O–H vibrations, along with organic functional groups associated with biochar. BET results demonstrated an increase in surface area and pore volume for the TiO2/biochar composites compared to pristine TiO2, while FESEM images showed well-dispersed nanoscale particles (< 100 nm). UV-DRS analysis indicated band gap energies in the range of 3.1–3.2 eV. Photocatalytic experiments showed that the TiO2/biochar composite containing 20 wt.% rice straw-derived biochar exhibited the highest PCT degradation efficiency, achieving 94% removal within 180 min at an initial concentration of 10 mg/L. Moreover, the composite photocatalyst demonstrated good stability, maintaining degradation efficiencies of 91–94% over repeated reuse cycles. The findings underscore the efficacy of biochar derived from rice straw in modifying TiO2, positioning it as a promising and sustainable photocatalyst for the treatment of pharmaceutical wastewater. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.
Research Center for Catalysis, National Research and Innovation Agency (BRIN), KST BJ Habibie Serpong, Building 452, Tangerang Selatan, Banten, 15311, Indonesia; Chemistry Department, Faculty of Mathematics and Natural Science, Universitas Negeri Semarang, Central Java, Semarang, Indonesia; Research Center for Molecular Chemistry, National Research and Innovation Agency (BRIN), KST BJ Habibie Serpong, Building 456, Tangerang Selatan, Banten, 15311, Indonesia; Research Center for Photonics, National Research and Innovation Agency (BRIN), KST BJ Habibie Serpong, Tangerang Selatan, Banten, 15311, Indonesia
