Asymmetric Oxygen-Vacancy-Engineered Co-MoO3 Nanoconfined Catalytic Membrane for Deep Organoarsenic Removal

Environ Res. 2025 Jul 11:122312. doi: 10.1016/j.envres.2025.122312. Online ahead of print.

Abstract

Arsenic-containing toxic agents are characterized by high toxicity and high mobility, posing significant environmental and public health hazards worldwide. Therefore, developing effective treatment materials and strategies represents a key research focus in sustainable processing technology. Herein, we developed a novel Co-MoO3/GO confined catalytic membrane enriched with asymmetric oxygen vacancies for activating peroxymonosulfate (PMS) towards the efficient degradation of p-arsinic acid (p-ASA). Experimental characterization indicates that Co-MoO3/GO membranes possess enhanced oxygen vacancies which, synergizing with electron-deficient Co reaction centers, shift the reaction pathway from a traditional radical mechanism to a predominant non-radical pathway. These membranes enable the selective generation of singlet oxygen (1O2) and exhibit resistance to external environmental factors (e.g., pH range of 2.0-10 and the presence of coexisting anions). The optimized Co-MoO3/GO catalytic membrane/PMS system achieved 97.91% removal of p-ASA within 1.0 min, exhibiting a degradation rate constant (k) of 23.79 s-1, four orders of magnitude higher than that observed in traditional powder batch reactions (k = 0.082 min-1). Furthermore, the Co-MoO3/GO membrane demonstrated excellent regeneration capability, maintaining high functionality during 60 h of continuous operation. The leaching concentrations of cobalt and molybdenum ions were significantly below the permissible limit of 1.0 mg/L. These findings demonstrate that this work provides new insights into the design of efficient and stable catalytic membranes for advanced wastewater treatment applications.

Keywords: Asymmetric Co-O(V)-Mo site; Catalytic membrane; Mass transfer; Organoarsenic; Singlet oxygen.