Fadhillah Choirunnisa, Khirunisa Mufidah, Erma Surya Yuliana, Suriati Sufian, Masruroh, Kusumandari, Hari Wisodo, Nandang Mufti
Water pollution caused by pathogenic bacteria, such as Escherichia coli and Staphylococcus aureus , is a serious environmental and health issue, necessitating the development of more effective treatment methods. TiO2/CQD-SCB composites can be easily synthesized from sugarcane bagasse (SCB) waste using the hydrothermal method with various variations of CQD-SCB (0-5 mL). These composites offer advantages such as easy modification, good chemical stability, high surface area, electron transfer ability, optical characteristics, and antibacterial photocatalytic properties. XRD results showed that the TiO2 crystals have an anatase phase with a tetragonal structure and retain this phase after undergoing the hydrothermal process and being composited with CQD-SCB. The presence of C–H, C O, C C, and Ti–O–C functional groups detected by FTIR indicates the success of CQD-SCBs in compositing with TiO2. The morphology of CQD-SCB is approximately 5 nm and successfully decorates the surface of TiO2. SEM analysis showed that the addition of CQD-SCB to a specific volume did not cause high particle agglomeration. BET analysis shows that variations in the addition of CQDs to the TiO2/CQD composite affect the surface area and pore properties in a non-linear manner. PL analysis evaluated the electron-hole recombination mechanism and showed that adding CQD-SCB at a particular volume could suppress electron-hole recombination, making it effective as a photocatalyst material. The composite with the addition of CQD CSB up to 3 mL demonstrated the most optimal antibacterial effectiveness in inhibiting bacterial growth under visible light, characterized by inhibition zones of 11.18 mm for E. coli and 17.78 mm for S. aureus bacteria, respectively. Meanwhile, lower antibacterial effectiveness was seen in the test without light. This material has good antibacterial activity and can be a candidate as an antibacterial photocatalyst material. © 2026 Elsevier B.V.
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang No. 5, Malang, 65145, Indonesia; Chemical Engineering Department, Universiti Teknologi PETRONAS, Sri Iskandar, Perak, Bandar, 32610, Malaysia; Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Brawijaya, Malang, 65145, Indonesia; Department of Physics, Faculty of Mathematics and Natural Science, Universitas Sebelas Maret, Jl. Ir. Sutami 36 A, Central Java, Surakarta, 57126, Indonesia; Centre of Advanced Materials for Renewable Energy, Universitas Negeri Malang, Jl. Semarang No. 5, Malang, 65145, Indonesia
