【摘要】 高级氧化工艺（AOPs）是一种处理有机污染物的极具吸引力的技术.大量的前期研究工作集中在通过芬顿反应（Fenton）降解有机污染物.然而,芬顿反应需要在酸性条件下进行,必须在其过程中进行预处理.同时,反应后产生的含铁污泥需要进一步处理以满足排放要求,从而限制了芬顿反应的发展.作为另一种AOPs,光催化技术因反应条件温和、操作简单和选择性好等优点受到广泛关注.研究表明,各种铁基和铜半导体光催化材料形成光-芬顿（Photo-Fenton）系统,可有效解决芬顿反应中高价金属离子/低价金属离子的循环问题.为了充分利用芬顿氧化技术和光催化氧化技术在降解有机污染物方面的各自优势,构建具有宽太阳光谱响应的新型光芬顿催化剂具有重要意义.由于其独特的层状结构和优越的有机物光催化性能, Bi₂WO₆作为结构最为简单的钙钛矿型层状氧化物,其禁带宽度为2.6–2.8 eV,可响应可见光,已成研究最多的光催化材料之一.研究表明,将Bi₂WO₆与合适的助催化剂耦合以构建异质结是提高光生载流子分离效率、拓宽Bi₂WO₆可见光响应范围的一种有效策略.在众多的窄带隙半导体助催化材料中,Cu₂ZnSnS₄作为一种p-型窄带隙半导体,可以响应可见光甚至近红外光.近年来,已经广泛报道了Cu2ZnSnS4可以作为与其他半导体光催化剂进行结合以提高光催化活性的有效助催化剂.在本文中,新型Cu₂ZnSnS₄/Bi₂WO₆（CZTS/BWO）异质结构通过简单的二次溶剂热法构建.异质结的成功形成得到了一系列表征方法的证实,比如XPS和HR-TEM.光催化活性结果表明,制备的CZTS/BWO异质结对有机污染物的降解具有优异的光催化性能,特别是当CZTS相对于异质结中BWO的质量分数为2%时.此外,加入过氧化氢（H₂O₂）可进一步提高染料和抗生素的降解效率.增强的光催化和光芬顿降解性能主要是由于BWO的引入,其提供了更多的活性位点,扩展了太阳光谱响应范围并加速了Cu（Ⅱ）/Cu（Ⅰ）的循环.催化剂的催化活性在经过四次循环实验后并没有显著降低.最终我们合理假设了光催化和光-芬顿催化机理.本项研究可为设计新型光-芬顿催化剂提供新的视角,即共同利用光催化活性和芬顿活性进行废水中残留有机物的净化.更多还原

【Abstract】 In this work, a set of novel Cu₂ZnSnS₄/Bi₂WO₆（CZTS/BWO） two-dimensional（2 D）/two-dimensional（2 D） type-Ⅱ heterojunctions with different CZTS weight ratios（1%, 2%, and 5%） were successfully synthesized via a brief secondary solvothermal process. The successful formation of the heterojunctions was affirmed by characterization methods such as X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. The photocatalytic activity results showed that the prepared CZTS/BWO heterojunctions had excellent photocatalytic behaviors for organic degradation, especially when the mass fraction of CZTS with respect to BWO in the composite was 2%. Moreover, the addition of hydrogen peroxide（H₂O₂） could further improve the dye and antibiotic degradation efficiencies. The reinforced photocatalytic and photo-Fenton degradation performance were primarily attributable to the introduction of BWO, which afforded increased active sites, expanded the solar spectral response range, and accelerated the cycle of Cu（Ⅱ）/Cu（Ⅰ）; after four cycling times, its catalytic activity did not decrease significantly. In addition, reasonable hypotheses of the photocatalytic and photo-Fenton catalytic mechanisms were formulated. This study is expected to provide a visual approach for designing a novel photo-Fenton catalyst to jointly utilize the photocatalytic and Fenton activities, which can be better applied to the purification of residual organics in wastewater.更多还原