Near-infrared light enhanced oxygen vacancies on metal organic frameworks through photothermal effect for peroxydisulfate activation to remove organic pollutants

Peroxydisulfate (PDS)-based advanced oxidation processes (AOPs) are a promising strategy for addressing the challenges of contamination in aqueous environment. Taking advantage of solar energy based photocatalysis showed great potential on PDS activation for pollution control. However, the limited usage of near-infrared (NIR) region by photocatalysts restricted the realization of using full sunlight energy. Herein, zeolitic imidazolate frameworks derived materials (ZNC) with oxygen vacancies (VO) are designed and obtained, which can efficiently activate PDS under NIR light due to the photothermal effect, exhibiting superior carbamazepine (CBZ) degradation performance (84% of CBZ within 60 min). Further quenching tests and electron paramagnetic resonance detection demonstrate that the photothermal effect can enhance the concentration of oxygen vacancies on the surface and facilitate charge separation of ZNC, which effectively activate PDS to generate O-2(center dot-), O-1(2), and h(+), thus significantly enhancing the photocatalytic degradation of CBZ. Additionally, combining the results of intermediates analysis and DFT calculation, a systematic CBZ degradation pathway by two tracks is proposed. Moreover, the overall potential risks of CBZ are expected to be weakened in the ZNC/PDS/NIR process through photothermal catalytic degradation. Thus, a new strategy is provided for optimizing the use of solar energy to boost PDS activation for water purification.