Zhao Guanshu, Ding Jing, Ren Jiayi, Zhao Qingliang, Mao Chengliang, Wang Kun, Ye Jessica, Chen Xueqi, Wang Xianjie, Long Mingce
State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
Solar Fuels Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
Environ Sci Ecotechnol. 2024 Feb 28;20:100405. doi: 10.1016/j.ese.2024.100405. eCollection 2024 Jul.
The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies. Sulfate radical-based advanced oxidation has emerged as an attractive solution, offering high selectivity, enduring efficacy, and anti-interference ability. Among many technologies, sulfite activation, leveraging its cost-effectiveness and lower toxicity compared to conventional persulfates, stands out. Yet, the activation process often relies on transition metals, suffering from low atom utilization. Here we introduce a series of single-atom catalysts (SACs) employing transition metals on g-CN substrates, effectively activating sulfite for acetaminophen degradation. We highlight the superior performance of Fe/CN, which demonstrates a degradation rate constant significantly surpassing those of Ni/CN and Cu/CN. Our investigation into the electronic and spin polarization characteristics of these catalysts reveals their critical role in catalytic efficiency, with oxysulfur radical-mediated reactions predominating. Notably, under visible light, the catalytic activity is enhanced, attributed to an increased generation of oxysulfur radicals and a strengthened electron donation-back donation dynamic. The proximity of Fe/CN's d-band center to the Fermi level, alongside its high spin polarization, is shown to improve sulfite adsorption and reduce the HOMO-LUMO gap, thereby accelerating photo-assisted sulfite activation. This work advances the understanding of SACs in environmental applications and lays the groundwork for future water treatment technologies.
难降解有机物在水生环境中普遍存在，因此需要创新的去除策略。基于硫酸根自由基的高级氧化技术已成为一种有吸引力的解决方案，具有高选择性、持久的有效性和抗干扰能力。在众多技术中，亚硫酸盐活化因其成本效益高且毒性低于传统过硫酸盐而脱颖而出。然而，活化过程通常依赖于过渡金属，存在原子利用率低的问题。在此，我们介绍了一系列在g-CN基底上负载过渡金属的单原子催化剂（SACs），它们能有效活化亚硫酸盐以降解对乙酰氨基酚。我们强调了Fe/CN的卓越性能，其降解速率常数显著超过Ni/CN和Cu/CN。我们对这些催化剂的电子和自旋极化特性的研究揭示了它们在催化效率中的关键作用，其中氧硫自由基介导的反应占主导。值得注意的是，在可见光下，催化活性增强，这归因于氧硫自由基生成增加以及电子给予-反馈给予动态增强。Fe/CN的d带中心与费米能级的接近程度及其高自旋极化表明，这有助于改善亚硫酸盐吸附并减小HOMO-LUMO能隙，从而加速光辅助亚硫酸盐活化。这项工作增进了对SACs在环境应用中的理解，并为未来的水处理技术奠定了基础。
