Acid-induced molecule self-assembly synthesis of Z-scheme WO3/g-C3N4 heterojunctions for robust photocatalysis against phenolic pollutants
Acid-induced molecule self-assembly synthesis of Z-scheme WO3/g-C3N4 heterojunctions for robust photocatalysis against phenolic pollutants
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DOI：
10.1016/j.cej.2020.126354
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发表时间：
2021
影响因子：
15.1
通讯作者：
Jiaqi Meng;Xinyue Wang;Yunqing Liu;M. Ren;Xueyan Zhang;Xuhui Ding;Yihang Guo;Yuxin Yang
中科院分区：
文献类型：
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作者：
Jiaqi Meng;Xinyue Wang;Yunqing Liu;M. Ren;Xueyan Zhang;Xuhui Ding;Yihang Guo;Yuxin Yang
寻找有效的方法来提高载流子的分离和光氧化能力是设计高效降解有机污染物的石墨化氮化碳基光催化剂的迫切需要。本文采用原位酸诱导三聚氰胺和钨酸钠自组装结合水热处理的方法，通过形成WO 3/三聚氰胺-氰尿酸超分子复合物，制备了掺杂氧的多孔片状WO 3/g-C3 N4异质结;同时，通过选择不同的短链羧酸，可以进一步调控WO 3/g-C3 N4纳米片的形貌。在降解酚类污染物对乙酰氨基酚和对羟基苯甲酸甲酯的实验中，该异质结表现出比本体g-C3 N4和超分子g-C3 N4更强的可见光催化活性.活性物种捕集、光电化学和光致发光等测试结果表明，这种优异的活性主要是由特殊的Z-模式电荷转移方式所决定的，这种电荷转移方式既能加速载流子的分离，又能同时保持g-C3 N4导带电子和WO 3价带空穴的强氧化还原能力;此外，多孔片状纳米结构和氧掺杂也通过改善光捕获、提供丰富的活性位点、缩短载流子迁移距离和进一步促进载流子分离而对活性产生积极影响。LC-MS分析和TOC监测表明，目标污染物在空穴、超氧阴离子和羟基自由基的氧化作用下被完全降解。
Searching for effective strategies of boosting charge carrier separation and improving photooxidation ability are highly desirable to design graphitic carbon nitride-based photocatalysts for efficient organic pollutant degradation. Here we demonstrate anin situacid-induced self-assembly of melamine and sodium tungstate method combined with hydrothermal treatment, by forming WO3/melamine-cyanuric acid supramolecular complex, to fabricate porous sheet-like WO3/g-C3N4heterojunctions with oxygen doping; meanwhile, the morphology of WO3/g-C3N4nanosheets can be further regulated by selecting different short-chain carboxylic acids. The heterojunctions exhibit enhanced visible-light photocatalytic activity than bulk g-C3N4and supramolecule-based g-C3N4in degradation of phenolic pollutants, acetaminophen and methylparaben. The tests including active species trapping, photoelectrochemistry and photoluminescence firmly evidence that the extraordinary Z-scheme charge transfer manner plays dominated role to this excellent activity, which can accelerate charge carrier separation and retain powerful redox ability of electrons on conduction band of g-C3N4and holes on valence band of WO3simultaneously; additionally, porous sheet-like nanostructures and oxygen doping also positively influence the activityviaimproving light harvesting, providing plentiful active sites, shortening charge carrier migration distance and further facilitating charge carrier separation. LC–MS analysis and TOC monitoring find the target pollutants are completely degraded under oxidation of holes, superoxide and hydroxyl radicals.