Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, Guangdong 523808, China.
Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China.
Sci Total Environ. 2020 Dec 1;746:141009. doi: 10.1016/j.scitotenv.2020.141009. Epub 2020 Jul 19.
In-situ construction of heterojunction photocatalyst on two-dimensional (2D) TiC MXene substrate has been proved to be a feasible method to enhance the photocatalytic degradation of organic pollutants. However, the limited interlayer spacing of 2D TiC hinders the in-situ growth of TiO photocatalyst. Herein, the intercalation strategy was developed in deep eutectic solvents (DESs) method to achieve interlayer expansion of TiC and improve TiC-derived photocatalyst performance. Because of the intercalation of choline cations, the DESs method synthesized TiC (TiC-DES) had the larger c-lattice parameter than that of traditional HF method synthesized TiC (TiC-HF). The interlayer space of TiC-DES could be intercalated with more water molecule for oxidization of the Ti atoms, which remarkably promoted the in-situ growth of TiO crystals. The formed heterojunction between (001) and (101) facets enhanced carriers separation. The TiC substrate with excellent conductivity further promoted carriers transfer. As a result, TiC/TiO photocatalyst exhibited superior perfluorooctanoic acid (PFOA) removal performance (almost 100% removal efficiency and 49% defluorination efficiency within 16 h) compared with the traditional TiC-HF/TiO (22% removal efficiency and 12% defluorination efficiency within 16 h). This study provides a feasible strategy for enhancing photocatalytic degradation of PFOA by TiC MXene-derived heterojunction photocatalyst.
在二维（2D）TiC MXene 基底上原位构建异质结光催化剂已被证明是增强有机污染物光催化降解的一种可行方法。然而，2D TiC 的有限层间距限制了 TiO 光催化剂的原位生长。在此，我们开发了在深共熔溶剂（DESs）法中的插层策略，以实现 TiC 的层间扩展并提高 TiC 衍生光催化剂的性能。由于胆碱阳离子的插层，DESs 法合成的 TiC（TiC-DES）具有比传统 HF 法合成的 TiC（TiC-HF）更大的 c-晶格参数。TiC-DES 的层间空间可以插入更多的水分子来氧化 Ti 原子，这显著促进了 TiO 晶体的原位生长。（001）和（101）面之间形成的异质结增强了载流子分离。具有优异导电性的 TiC 基底进一步促进了载流子转移。结果，TiC/TiO 光催化剂表现出优异的全氟辛酸（PFOA）去除性能（在 16 小时内几乎达到 100%的去除效率和 49%的脱氟效率），而传统的 TiC-HF/TiO 则为 22%的去除效率和 12%的脱氟效率（在 16 小时内）。本研究为通过 TiC MXene 衍生的异质结光催化剂增强 PFOA 的光催化降解提供了一种可行的策略。
