Liu Guoshuai, You Shijie, Zhang Yujian, Huang Hong, Spanjers Henri
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; Department of Water Management, Section Sanitary Engineering, Delft University of Technology, PO Box 5048, 2600 GA Delft, the Netherlands.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
J Colloid Interface Sci. 2019 Oct 1;553:666-673. doi: 10.1016/j.jcis.2019.06.072. Epub 2019 Jun 21.
To guarantee drinking water security, removal of bromate (BrO) has garnered plenty of attention in water treatment. In current study, we have developed a novel conjugated donor-acceptor (D-A) photocatalyst (4,4''-bis(diphenylamino)-[1,1':4',1''-terphenyl]-2',5'-dicarbaldehyde, BDTD) with supramolecule architecture assembling via intermolecular CH···O hydrogen bonds and CH···π interactions. Both diffuse reflectance spectrum (DRS) and density functional theoretical (DFT) calculations gave the bandgap of E = 2.21 eV, clearly indicating the visible-light response of BDTD supramolecule. The calculations showed that BDTD supramolecule could induce nearly 100% removal of BrO stably at pH-neutral condition driven by visible light, accounting for a first-order kinetic constant being one order of magnitude higher than most of the photocatalysts previous reported. As demonstrated by our electron scavenger experiment and DFT calculations, the BDTD supramolecule should undergo the photocatalytic reduction of BrO through direct reduced by the lowest unoccupied molecular orbital of conduction band (potential of -1.705 V versus standard hydrogen electrode) electron. The BDTD supramolecule may serve as an attractive photocatalyst by virtue of response to visible light, efficient charge transfer and separation as well as high photocatalytic activity, which will make the removal of BrO in water much easier, more economical and more sustainable.
为保证饮用水安全，溴酸盐（BrO）的去除在水处理中备受关注。在当前研究中，我们开发了一种新型的共轭供体-受体（D-A）光催化剂（4,4''-双（二苯胺基）-[1,1':4',1''-三联苯]-2',5'-二甲醛，BDTD），其通过分子间CH···O氢键和CH···π相互作用组装成超分子结构。漫反射光谱（DRS）和密度泛函理论（DFT）计算均给出了E = 2.21 eV的带隙，清楚地表明了BDTD超分子的可见光响应。计算表明，BDTD超分子在可见光驱动下，在pH中性条件下可稳定诱导近100%的BrO去除率，其一级动力学常数比先前报道的大多数光催化剂高一个数量级。正如我们的电子捕获剂实验和DFT计算所表明的，BDTD超分子应通过导带最低未占据分子轨道（相对于标准氢电极电位为-1.705 V）的电子直接还原，从而对BrO进行光催化还原。BDTD超分子凭借对可见光的响应、高效的电荷转移和分离以及高光催化活性，可能成为一种有吸引力的光催化剂，这将使水中BrO的去除更加容易、经济和可持续。
