Dually engineered CdSe/CdTe nanorod heterojunction enables efficient, sacrificial agent-free photoremoval of U(VI)

The pollution of uranium (U)-containing radioactive wastewater has been long regarded as a serious threat to the ecosystems and the health of human beings. Herein, we report a CdSe/CdTe heterojunction that shows efficient U(VI) removal viable under the simulated/real solar light. Up to 92 % of total U(VI) (C0 = 30 mg/L) can be rapidly removed within 5 min without using any sacrificial agent or protective gas, this high removal efficiency remains stable in the presence of various interfering ions. Detailed analyses indicate that multiple interfaces can be constructed in the heterojunction using a facile two-step hydrothermal method. These interfaces can accommodate photocatalysis and yield a built-in electric field to separate the photogenerated electron/hole pairs better. Meanwhile, the ingeniously anchored Te2- in the heterojunction, which concurrently acts as an endogenous hole scavenger and a hydroxyl radical sacrifice, also makes a positive contribution. Benefiting from the above synergy, removal rate of U(VI) can be optimized to as high as 14.4 mmol/(g·h). This work offers a general strategy for the rational design of high-performance photocatalysts, potentially paving the way for cleaner and safer nuclear power use.