Zhang Yanshi, Li Fengmin, Wang Xiao, Zhao Chengxuan, Zhang Yiqiao, Wang Chunguang, Li Yanlu, Zhao Xian, Xu Chunhua
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
State Key Lab of Crystal Materials, Shandong University, Jinan 250100, China.
J Hazard Mater. 2024 Sep 15;477:135274. doi: 10.1016/j.jhazmat.2024.135274. Epub 2024 Jul 21.
The reactivity and stability of zero-valent iron (ZVI) and sulfidated zero-valent iron (S-ZVI) are inherently contradictory. Iron sulfides (FeS) on the S-ZVI surface play multiple roles, including electrostatic adsorption and catalyzing reduction. We proposed to balance the reactivity and air stability of S-ZVI by regulating FeS. Benefiting from the superior coordination and accelerate electron transport capabilities of phosphate, herein, eco-friendly ammonium dihydrogen phosphate (ADP) was employed to synthesize N, P, and S-incorporated ZVI (NPS-ZVI) and regulate the FeS. Raman, FTIR, XPS, and density functional theory (DFT) calculations were combined to reveal that HPO acts as the main P species on the Fe surface. The superior reactivity of NPS-ZVI was quantified by k, k, and k of Cr(VI), which were 210.77, 27.44, and 211.17-fold than ZVI, respectively. NPS-ZVI demonstrated excellent reusability, with no risk of secondary pollution. Critically, NPS-ZVI could effectively maintain FeS stability under the combination of diffusion limitation and surface protection mechanisms of ADP. The superior reactivity of NPS-ZVI was attributed to the fact that ADP maintains FeS stability and accelerates electron transport. This study provides a novel strategy in balancing the reactivity and air stability of S-ZVI and offers theoretical support for material modification.
零价铁（ZVI）和硫化零价铁（S-ZVI）的反应活性和稳定性存在内在矛盾。S-ZVI表面的硫化铁（FeS）发挥多种作用，包括静电吸附和催化还原。我们提议通过调控FeS来平衡S-ZVI的反应活性和空气稳定性。得益于磷酸盐优异的配位能力和加速电子传输能力，在此采用环境友好型磷酸二氢铵（ADP）合成氮、磷、硫掺杂的ZVI（NPS-ZVI）并调控FeS。结合拉曼光谱、傅里叶变换红外光谱、X射线光电子能谱和密度泛函理论（DFT）计算揭示HPO是Fe表面的主要P物种。NPS-ZVI对Cr(VI)的k、k和k量化了其优异的反应活性，分别是ZVI的210.77、27.44和211.17倍。NPS-ZVI表现出优异的可重复使用性，不存在二次污染风险。关键的是，NPS-ZVI在ADP的扩散限制和表面保护机制共同作用下能有效维持FeS的稳定性。NPS-ZVI的优异反应活性归因于ADP维持FeS稳定性并加速电子传输。本研究为平衡S-ZVI的反应活性和空气稳定性提供了一种新策略，并为材料改性提供了理论支持。
