Magnesium-promoted rapid self-reconstruction of NiFe-based electrocatalysts toward efficient oxygen evolution.

The acceleration of active sites formation through surface reconstruction is widely acknowledged as the crucial factor in developing high-performance oxygen evolution reaction (OER) catalysts for water splitting. Herein, a simple one-step corrosion method and magnesium (Mg)-promoted strategy are reported to develop the NiFe-based catalyst with enhanced OER performance. The Mg is introduced in NiFe materials to preparate a "pre-catalyst" Mg-Ni/Fe2O3. In-situ Raman shows that Mg doping would accelerate the self-reconstruction of Ni/Fe2O3 to form active NiOOH species during OER. In-situ infrared indicates that Mg doping benefits the formation of *OOH intermediate. Theoretical analysis further confirms that Mg doping can optimize the adsorption of oxygen intermediates, accelerating the OER kinetics. Accordingly, the Mg-Ni/Fe2O3 catalyst exhibits excellent OER performance with overpotential of 168 mV at 10 mA cm-2. The anion exchange membrane water electrolyzer achieved 200 mA cm-2 at voltage of 1.53 V, showing excellent stability over 500 h as well. This work demonstrates the potential of Mg-promoted strategy in regulating the activity of transition metal-based OER electrocatalysts.

Detoxification and metabolism of glyphosate by a Pseudomonas sp. via biogenic manganese oxidation.

Biogenic manganese oxides (BMO) are widely distributed in groundwater and provides promise for adsorbing and oxidizing a wide range of micropollutants, however, the continuous biodegradation and bioavailability of micropollutants via cycle biogenic Mn(II) oxidation remains to be elucidated. In this study, glyphosate was degraded and to serve as the nutrient source by a Pseudomonas sp. QJX-1. The addition of glyphosate will not affect the Mn(II) oxidation function of the strain but will affect its Mn(II) oxidation process and effect. The glyphosate degradation products could further be used as the C, N and P sources for bacterium growth. Analysis of the RNA-seq data suggested that Mn(II) oxidation driven by oxidoreductases for glyphosate degradation. The long-term column experiments using biological Mn(II) cycling to realize continuous detoxification and metabolism of glyphosate, and thus revealed the synergism effects of biological and chemical conversion on toxic micropollutants and continuous metabolism in an aquatic ecosystem.