Achieving Energy-Saving,Continuous Redox Flow Desalination with Iron Chelate Redoxmers

Desalination of saline water is becoming an increasingly critical strategy to overcome the global challenge of drinkable water shortage,but current desalination methods are often plagued with major drawbacks of high energy consumption,high capital cost,or low desalination capacity.To address these drawbacks,we have developed a unique continuous-mode redox flow desalination approach capitalizing on the characteristics of redox flow batteries.The operation is based on shuttled redox cycles of very dilute Fe^(2+)/Fe^(3+)chelate redoxmers with ultralow cell overpotentials.The air instability of Fe^(2+)chelate is naturally compensated for by its in situ electrochemical generation,making the desalination system capable of operations with electrolytes at any specified state of charge.Under unoptimized conditions,fast desalination rates up to 404.4 mmol·m^(−2)·h^(−1) and specific energy consumptions as low as 7.9 Wh·molNaCl^(−1) have been successfully achieved.Interestingly,this desalination method has offered an opportunity of sustainable,distributed drinkable water supplies through direct integration with renewable energy sources such as solar power.Therefore,our redox flow desalination design has demonstrated competitive desalination performance,promising to provide an energy-saving,high-capacity,robust,cost-effective desalination solution.

PtAu Bimetallic Heteronanostructures Made by Post-Synthesis Modification of Pt-on-Au Nanoparticles

Bimetallic PtAu heteronanostructures have been synthesized from Pt-on-Au nanoparticles,which were made from platinum acetylacetonate and gold nanoparticles.Using the Pt-on-Au nanoparticles as precursors,Pt-surface rich PtAu bimetallic heteronanostructures can be produced through controlled thermal treatments,as confirmed by field emission high-resolution transmission electron microscopy(HR-TEM)and elemental mapping using a high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM).Oxidation of formic acid was used as a model reaction to demonstrate the effects of varying composition and surface structure on the catalytic performance of PtAu bimetallic nanostructures.Cyclic voltammetry(CV)showed that these carbon-supported PtAu heteronanostructures were much more active than platinum in catalyzing the oxidation of formic acid,judging by the mass current density.The results showed that post-synthesis modification can be a very useful approach to the control of composition distributions in alloy nanostructures.

A review of Pt-based electrocatalysts for oxygen reduction reaction

Development of active and durable electro- catalyst for oxygen reduction reaction （ORR） remains one challenge for the polymer electrolyte membrane fuel cell （PEMFC） technology. Pt-based nanomaterials show the greatest promise as electrocatalyst for this reaction among all current catalytic structures. This review focuses on Pt- based ORR catalyst material development and covers the past achievements, current research status and perspectives in this research field. In particular, several important categories of Pt-based catalytic structures and the research advances are summarized. Key factors affecting the catalyst activity and durability are discussed. An outlook of future research direction of ORR catalyst research is provided.