Rechargeable Zn-CO Electrochemical Cells Mimicking Two-Step Photosynthesis.

Metal-CO batteries represent a promising priority for sustainable energy and the environment. However, CO utilization in nonaqueous electrolytes mostly involves difficult CO electrochemistry, leading to poor selectivity and limited cycle performance. Herein, an aqueous rechargeable Zn-CO electrochemical cell that tunably produced CO fuel gas (90% Faradaic efficiency) during cell discharge (cathodic reaction: CO + 2e + 2H → CO + H O) and O during cell charge at ≈2 V (cathodic reaction: H O → 1/2O + 2e + 2H ), mimicking the separate steps of CO fixation and water oxidation during photosynthesis while exhibiting the advantages of high efficiency, tunable products, and operation independent of sunlight is proposed and realized.

CO Overall Splitting by a Bifunctional Metal-Free Electrocatalyst.

Photo/electrochemical CO splitting is impeded by the low cost-effective catalysts for key reactions: CO reduction (CDRR) and water oxidation. A porous silicon and nitrogen co-doped carbon (SiNC) nanomaterial by a facile pyrolyzation was developed as a metal-free bifunctional electrocatalyst. CO -to-CO and oxygen evolution (OER) partial current density under neutral conditions were enhanced by two orders of magnitude in the Tafel regime on SiNC relative to single-doped comparisons beyond their specific area gap.

Mixed-Metal-Organic Framework Self-Template Synthesis of Porous Hybrid Oxyphosphides for Efficient Oxygen Evolution Reaction.

Developing an efficient, stable yet cost-effective electrocatalyst is the key link along the path to hydrogen fuels produced by water splitting. The current bottleneck in the water electrolysis technology is the sluggish oxygen-evolving reaction (OER) which is also central to the rechargeable metal-air batteries. Herein, we report a promising mixed-metal-organic framework (MMOF) self-template strategy to synthesize CoFe hybrid oxyphosphides with highly porous morphology.