%0 Journal Article
%@ 10106030
%A Wongso, V.
%A Chung, H.K.
%A Sambudi, N.S.
%A Sufian, S.
%A Abdullah, B.
%A Wirzal, M.D.H.
%A Ang, W.L.
%D 2020
%F scholars:13196
%I Elsevier B.V.
%J Journal of Photochemistry and Photobiology A: Chemistry
%R 10.1016/j.jphotochem.2020.112436
%T Silica�carbon quantum dots decorated titanium dioxide as sunlight-driven photocatalyst to diminish acetaminophen from aquatic environment
%U https://khub.utp.edu.my/scholars/13196/
%V 394
%X 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 � 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�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. © 2020 Elsevier B.V.
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