通过可见光催化产生单线态氧(1O2)将硫芥子气(HD)选择性氧化为无毒亚砜是一种有前途的降解策略。虽然PCN-224可以吸收可见光,它具有快速的电子-空穴复合和低氧化还原容量,这限制了HD退化的性能。二氧化钛(TiO2)是一种出色的光催化剂,但在降解HD方面缺乏可见光活性。在这项研究中,采用原位生长法制备了S型核壳结构的PCN-224@TiO2异质结,以延长TiO2的可见光吸收能力,抑制PCN-224的快速复合。通过调整Zr/Ti比优化界面形成和内部电场,以增强电荷转移,氧化还原容量,电子-空穴分离,和可见光的吸收。在这项研究中,通过一系列表征方法证明了基于Zr-O-Ti键的异质结复合材料的形成。通过实验和理论计算证明,PCN-224@TiO2在可见光条件下可以生成近100%的1O2,而无需牺牲剂,导致2-氯乙基乙基硫醚(CEES)的有效和选择性氧化,模拟HD,无毒的亚砜形式。
Selective oxidation of sulfur mustard gas (HD) to non-toxic sulfoxide by the visible-light-catalyzed generation of singlet oxygen (1O2) is a promising degradation strategy. Although PCN-224 can absorb visible light, it suffers from rapid electron-hole recombination and low redox capacity, which limits the performance of HD degradation. Titanium dioxide (TiO2) is an excellent photocatalyst but it lacks visible-light-activity in degrading HD. In this study, PCN-224@TiO2 heterojunction with S-type core-shell structure was synthesized by in-situ growth method to prolong the visible light absorption capacity of TiO2 and inhibit the rapid recombination of PCN-224. The interface formation and internal electric field were optimized by adjusting the Zr/Ti ratio to enhance the charge transfer, redox capacity, electron-hole separation, and visible light absorption. In this study, the formation of heterojunction composites based on Zr-O-Ti linkages is demonstrated by a series of characterization methods. It is demonstrated by experiments and theoretical calculations that PCN-224@TiO2 can generate nearly 100 % 1O2 under visible light conditions without a sacrificial agent, resulting in efficient and selective oxidation of 2-chloroethyl ethyl sulfide (CEES), a simulant of HD, to non-toxic sulfoxide form.