@article{scholars13196, publisher = {Elsevier B.V.}, year = {2020}, journal = {Journal of Photochemistry and Photobiology A: Chemistry}, volume = {394}, title = {Silica{\^a}??carbon quantum dots decorated titanium dioxide as sunlight-driven photocatalyst to diminish acetaminophen from aquatic environment}, note = {cited By 20}, doi = {10.1016/j.jphotochem.2020.112436}, author = {Wongso, V. and Chung, H. K. and Sambudi, N. S. and Sufian, S. and Abdullah, B. and Wirzal, M. D. H. and Ang, W. L.}, issn = {10106030}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081650849&doi=10.1016\%2fj.jphotochem.2020.112436&partnerID=40&md5=e9b159a83f2e99b288004ace3ff41ae7}, abstract = {The presence of pharmaceutical compound (i.e., acetaminophen) in aquatic environment has been declared as environmental issue since researchers found that it has potential risk to human health. Photocatalytic process as a promising method for waste degradation commonly employs titanium dioxide, TiO2. However, TiO2 has narrow light absorption and rapid charge recombination resulting in ineffective photocatalytic activity. In this study, silica {\^a}?? carbon quantum dots (Si-CQDs) from rice husk are decorated into TiO2 matrix through facile mixing approach to minimize the limitations of TiO2. Preliminary studies regarding TiO2 transformation and Si-CQDs incorporation in various amount were systematically investigated. It is observed that 1 wt is the optimum amount of Si-CQDs in composite in order to maximize the photocatalytic ability of TiO2. Under sunlight irradiation, 1 wt Si-CQDs/TiO2 composite is able to completely degrade 5 mg/L of acetaminophen within 240 min (33.3 faster than pure TiO2). The excellent performance of the composite is attributed to synergistic effect of Si-CQDs addition on TiO2 surface, which acted as photo sensitizer and electron trapper. Si-CQDs extend light absorption of TiO2 by reducing band gap energy from 3.20 to 3.12 eV, as confirmed by UV{\^a}??vis Diffuse Reflectance Spectroscopy (DRS) spectra. Photoluminescence (PL) spectra and N2 sorption isotherm reveal that Si-CQDs addition prolongs the lifetime of charge separation and improves surface area (17 larger than TiO2), respectively. The composite of Si-CQDs/TiO2 also demonstrates good stability which is beneficial for pharmaceutical waste removal in the future. {\^A}{\copyright} 2020 Elsevier B.V.} }