Electrocatalytic generation of reactive species and implications in microbial inactivation

Controlling microbial proliferation in water systems,including wastewater,recreational water,and drinking water,is essential to societal health.Microbial inactivation through electrochemically generated reactive species(RS)mediated pathways provides an effective route toward this microbial control.Herein we provide an overview of recent progress toward electrocatalytic generation of RS and their application in water disinfection,with a focus on the selective production of RS,the microorganism interactions with RS(including both RS mechanisms of action and innate microorganism responses to RS),and practical implementation of electrochemically generated RS for microbial inactivation.The article is concluded with a perspective where the challenges and opportunities of RS‐based electrochemical disinfection of water are highlighted,along with possible future research directions.

Rapid preparation of carbon-supported ruthenium nanoparticles by magnetic induction heating for efficient hydrogen evolution reaction in both acidic and alkalinemedia

Ruthenium has been hailed as a competitive alternative for platinum toward hydrogen evolution reaction(HER),a critical process in electrochemical water splitting.In this study,we successfully prepare metallic Ru nanoparticles supported on carbon paper by utilizing a novel magnetic induction heating(MIH)method.The samples are obtained within seconds,featuring a Cl-enriched surface that is unattainable via conventional thermal annealing.The best sample within the series shows a remarkable HER activity in both acidic and alkaline media with an overpotential of only-23 and-12 mV to reach the current density of 10 mA/cm^(2),highly comparable to that of the Pt/C benchmark.Theoretical studies based on density functional theory show that the excellent electrocatalytic activity is accounted by the surface metal-Cl species that facilitate charge transfer and downshift the d-band center.Results from this study highlight the unique advantages of MIH in rapid sample preparation,where residual anion ligands play a critical role in manipulating the electronic properties of the metal surfaces and the eventual electrocatalytic activity.

Oxygen Reduction Reaction Catalyzed by Carbon-Supported Platinum Few-Atom Clusters:Significant Enhancement by Doping of Atomic Cobalt

Oxygen reduction reaction(ORR)plays an important role in dictating the performance of various electrochemical energy technologies.As platinum nanoparticles have served as the catalysts of choice towards ORR,minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development.Herein,first-principle calculations show that carbon-supported Pt9 clusters represent the threshold domain size,and the ORR activity can be significantly improved by doping of adjacent cobalt atoms.This is confirmed experimentally,where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms,single atoms,few-atom clusters,and nanoparticles,depending on the initial feeds.The sample consisting primarily of Pt_(2~7)clusters doped with atomic Co species exhibits the best mass activity among the series,with a current density of 4:16Amg^(-1)_(Pt)at+0.85V vs.RHE that is almost 50 times higher than that of commercial Pt/C.

Ultrafast Preparation of Nonequilibrium FeNi Spinels by Magnetic Induction Heating for Unprecedented Oxygen Evolution Electrocatalysis

Carbon-supported nanocomposites are attracting particular attention as high-performance,low-cost electrocatalysts for electrochemical water splitting.These are mostly prepared by pyrolysis and hydrothermal procedures that are time-consuming(from hours to days)and typically difficult to produce a nonequilibrium phase.Herein,for the first time ever,we exploit magnetic induction heating-quenching for ultrafast production of carbon-FeNi spinel oxide nanocomposites(within seconds),which exhibit an unprecedentedly high performance towards oxygen evolution reaction(OER),with an ultralow overpotential of only+260 mV to reach the high current density of 100 mA cm^(-2).Experimental and theoretical studies show that the rapid heating and quenching process(ca.10^(3)K s^(-1))impedes the Ni and Fe phase segregation and produces a Cl-rich surface,both contributing to the remarkable catalytic activity.Results from this study highlight the unique advantage of ultrafast heating/quenching in the structural engineering of functional nanocomposites to achieve high electrocatalytic performance towards important electrochemical reactions.

Ultrafast synthesis of cobalt/carbon nanocomposites by magnetic induction heating for oxygen evolution reaction

Metal/carbon nanocomposites have shown great potential as high-performance,low-cost electrocatalysts owing largely to their unique metal-support interactions.These nanocomposites are typically prepared by conventional pyrolysis that is tedious and energy-intensive.Herein,we report the ultrafast preparation of cobalt/carbon nanocomposites by magnetic induction heating(MIH)of metal organic frameworks within seconds under an inert atmosphere.The resulting samples consist of cobalt nanoparticles encapsulated within defective carbon shells,and effectively catalyze oxygen evolution reaction(OER)in alkaline media.Among the series,the sample prepared at 400 A for 10 s exhibits the best OER performance,needing a low overpotential of+308 mV to reach the current density of 10 mA cm^(−2),along with excellent stability,and even outperforms commercial RuO_(2) at high overpotentials.This is ascribed to the charge transfer between the carbon scaffold and metal nanoparticles.Operando X-ray absorption spectroscopy measurements show that the electrochemically produced CoOOH species is responsible for the high electrocatalytic performance.The results highlight the unique potential of MIH in the development of effective nanocomposite catalysts for electrochemical energy technologies.