Current Opinion in Electrochemistry最新文献

Fuel cells (FCs) and hydrogen technologies are emerging renewable energy sources with promising results when applied to wastewater treatment (WWT). These devices serve not only for power generation, but some specific FCs can also be employed for degradation of pollutants and synthesis of intermediates needed in WWT. Microbial FCs are potent devices for WWT, even containing refractory pollutants. Despite being a nascent technology with high capital expenses, the use of cost-effective materials, reduction of operational cost, and increased generation of energy and value-added chemicals such as hydrogen will facilitate the market penetration through selected niches and hybridization with alternative WWT technologies.

Electrochemical interface imaging techniques enable a deeper understanding of the structure-activity relationship at electrochemical interfaces. Each imaging technique holds distinct capability and spatiotemporal resolution to visualize the interfacial process of individual particles in real-time. The advent of multimode imaging offers a more comprehensive view of a single sample by combining different imaging techniques to acquire plentiful information. This review highlights the recent advances in multimode imaging approaches for electrochemical interface process, including SECCM-based approaches, optical microscope-based approaches, and multi-optical mode imaging approaches. Key examples exhibiting the advantages of multimode imaging are selected and how these techniques reveal the activity of individual particles at electrochemical interfaces are discussed. Finally, we present some new perspectives on the development tendency of this field that will open new avenues for accelerated mechanistic understanding, rational materials design, and diverse electrochemical applications.

What occurs at the interface plays a crucial role in the nano-impact electrochemistry, especially for the electrocatalytic current amplification from heterogeneous inner-sphere reaction. Surface chemistry of electrode and impacting nanoparticles, electrolyte composition, and certain external conditions such as applied potential, unique setups, plasmonic effects, and magnetic fields will significantly affect the collision behavior and signals of single nano-electrocatalysts. Studying the effect of the above factors can provide new insights into the nature of NP-electrode interactions and their impact on electron transfer processes. This sheds light on the intrinsic electrocatalytic behavior of nanomaterials on a single entity level and the relevant fundamental electrochemistry. This review summarizes the recent work on modulation of electrocatalytic nano-impact systems by modifying the electrode and nanoparticle surface, adjusting solution composition, and tuning external conditions.

The development of highly efficient electrocatalysts requires a deeper understanding of their structure–activity relationship. Scanning electrochemical microscope (SECM) and scanning electrochemical cell microscope (SECCM) are powerful techniques for mapping surface activity site and investigating heterogeneous electrocatalytic processes down to the nanoscale in situ and even operando, thus playing a pivotal role in studying electrocatalytic mechanism. In this review, we introduce the fundamentals of SECM and SECCM, and the principles of the most frequently used operational modes. This review describes work done in SECM and SECCM since 2021 with a particular emphasis on emerging electrocatalytic applications and noteworthy trends.

Within single-entity electrochemistry (SEE), the subfield of nanoimpact electrochemistry (NIE) has rapidly expanded in recent years with advances in electrocatalysis and nanomaterial fabrication applications. In particular, recent developments concerning the hydrogen evolution reaction and the oxygen evolution reaction will be discussed as two reactions integral to water splitting for hydrogen production. Moreover, the application of NIE in electrocatalyst fabrication methods will be discussed with a focus on metal deposition onto nonmetallic nanoparticles and bimetallic nanoparticles.

Stochastic electrochemical measurement has come of age as a powerful analytical tool in corrosion science, electrophysiology, and single-entity electrochemistry. It relies on the fundamental trait that most electrochemical processes are stochastic and discrete in nature. Stochastic measurement of a single entity probes the charge transfer from a few or even one electroactive species. In corrosion, the stochastic measurements capture either the average amplitude/frequency of many events taking place spontaneously or probe discrete transients, signifying localized dissolution. The measurement principles vary in corrosion, single-entity, and electrophysiology, yet the main quantifiable values are commonly the frequency and amplitude of events. This perspective delves into the methodologies for the analysis and deconvolution of stochastic signals in electrochemistry. Ranging from visual assessment of transients to time/frequency analyses of the data and state-of-the-art machine learning, these methodologies mainly aim at identifying patterns, singular events, and rates of electrochemical processes from stochastic signals.

Heat is unavoidably generated during the dynamic formation and relaxation processes of the electrical double layer (EDL), affecting the performance, durability, and safety of electrochemical systems. Achieving a nuanced understanding of this heat generation is crucial for effectively addressing thermal challenges at their source. This review delivers a comprehensive overview of recent advancements in comprehending the heat generation associated with EDL dynamics. Investigations using calorimetry have observed both reversible and irreversible heat in various electrode–electrolyte systems. Insights from the theories of thermodynamics and kinetics have enhanced our understanding of these processes. Moreover, recent advancements in molecular dynamics simulations have significantly enhanced this understanding, providing a more accurate microstructural viewpoint. Finally, the review identifies existing gaps in our knowledge of EDL-related heat generation and proposes areas for future research.

Increasing demand for sustainable energy resources necessitates the advancements of electrochemical energy storage and conversion (EESC) devices. For optimal device performance, it is imperative to have comprehensive insight into the multiple electrochemical processes occurring at the electrode–electrolyte interface from the atomic/molecular scale to the nanoscale. Scanning electrochemical microscopy (SECM), a powerful in situ technique, offers the unique advantage of probing electrochemical processes and topography with nanoscale resolution. This review emphasizes the crucial role of SECM in providing localized information about surface heterogeneity, electrode reactions, and their kinetics that lead to performance deterioration in batteries, fuel cells, and supercapacitors.

Gaining fundamental insights into the interfacial electrochemistry in advanced battery systems, specifically the solid electrolyte interphases (SEIs), is key for the development of their practical applications. Electrochemical atomic force microscopy (EC-AFM) and its derivatives have been regarded as powerful and promising tools to reveal the SEI formation and evolution at the micro-/nanoscale and in real time. In this review, we present EC-AFM observations of the dynamic processes and structures of SEI in both liquid and solid electrolyte batteries. We show functional modes that enable the high-resolution monitoring of local modulus, viscosity, and ionic migration. Related techniques, mainly scanning electrochemical microscopy, are also introduced for probing the electrochemical reactivity and its distribution.