Well-designed heterojunction semicounductor coupled with high-conductive cocatalyst can obtain boosted photocatalytic activity. Herein, a novel three-dimensional (3D) hollow heterojunction was prepared by coating the indium zinc sulfide (ZnIn₂S₄) nanosheets with rich-zinc vacancies (V_Zn) on 3D hollow titanium carbide (Ti₃C₂). The obtained 3D hollow heterojunction (Ti₃C₂@ZnIn₂S₄) achieved effective optical collection and promoted the separation and transmission of photogenerated carriers as well as the surface reaction of spatial separation. In addition, time-resolved photoluminescence and steady-state photoluminescence spectra indicated that the existence of V_Zn and the introduction of hollow Ti₃C₂ spherical shell effectively inhibited the recombination of photogenerated carriers and accelerated their separation and transmission, thus further enhancing the photocatalytic activity. In addition, the introduction of 3D hollow Ti₃C₂ benefited a larger specific surface area for heavy metal adsorption. Due to the unique structural and compositional characteristics, the heterojunction showed high efficiency of Cr(VI) reduction under visible light. In particular, the optimal Ti₃C₂@ZnIn₂S₄ heterojunction (1%-Ti₃C₂@ZnIn₂S₄) achieved 100% removal of Cr(VI) within 25 min, with a reaction rate constant of 0.225, which was 8.5 times higher than that of the pristine ZnIn₂S₄. The superior reusability and structural stability further indicated the MXene-based novel photocatalyst is promising for application in environmental remediation.

设计良好的异质结半导体与高导电助催化剂的结合可以提高光催化活性。本文中，通过在3D空心碳化钛（Ti ₃ C ₂）上涂覆具有富锌空位（V _Zn）的铟锌硫化物（ZnIn ₂ S ₄）纳米片，制备了新颖的三维（3D）空心异质结。获得的3D空心异质结（Ti ₃ C ₂ @ZnIn ₂ S ₄）实现了有效的光学收集，并促进了光生载流子的分离和传输以及空间分离的表面反应。此外，时间分辨的光致发光和稳态光致发光光谱表明，V _Zn的存在和空心Ti ₃ C ₂球形壳的引入有效地抑制了光生载流子的复合并加速了它们的分离和透射，从而进一步增强了光催化作用。活动。此外，引入了3D空心Ti ₃ C ₂有利于更大的比重表面吸附重金属。由于独特的结构和组成特征，异质结在可见光下显示出高效率的Cr（VI）还原。特别是，最佳的Ti ₃ C ₂ @ZnIn ₂ S ₄异质结（1％-Ti ₃ C ₂ @ZnIn ₂ S ₄）在25分钟内实现了Cr（VI）的100％去除，反应速率常数为0.225，是原始ZnIn ₂ S _4的8.5倍。优异的可重复使用性和结构稳定性进一步表明，基于MXene的新型光催化剂有望用于环境修复。