Atomic Insights into the Heterogeneous Crystallization of Manganese (Oxyhydr)oxides on Typical Iron (Oxyhydr)oxides: from Adsorption to Oxidation to Crystallization

• DOI: 10.1021/acs.est.4c10093
• Publication Date: 2025-02-20T14:58:21Z
• Authors: Shouhao Tong; Hongyan Wei; Junming Zhou; Yixuan Yang; Runliang Zhu; Qingze Chen; Xiande Xie; Qing Hu; Michael F. Hochella; Jing Liu

Heterogeneous crystallization of manganese (oxyhydr)oxides (MnOx) on iron (FeOx) is crucial for the biogeochemical cycling Mn, yet atomic-level insights into this process are important but relatively limited. Herein, we revealed distinct adsorption, oxidation, and mechanisms Mn hematite (Hem), ferrihydrite (Fhy), goethite (Gth). Gth exhibited highest ability in Mn(II) removal followed by Hem Fhy. Manganite hausmannite were main MnOx products with proportions, morphologies cross systems. growth involve surface-induced nucleation, particle attachment (CPA), self-catalyzed growth. On Fhy, was dominant; Gth, nucleation prevalent, supplemented CPA; combined all three mechanisms. These led to nanoparticles primarily nanowires manganite those displaying lower aspect ratios. Differences structure morphology attributed Mn(II)-FeOx complexation, FeOx electronic band structure, crystal mismatch between FeOx, which respectively influenced direct indirect electron transfer heterogeneous efficiency. This work advances our understanding at nanoscale, explaining diverse different environments.