Current Opinion in Electrochemistry最新文献

Advanced electrochemical oxidation processes often generate radicals and/or oxidants with short lifetimes and high oxidation potentials to destroy organic pollutants in wastewater, and generation depends on the pH, supporting electrolyte, counter-electrode, and other experimental conditions. This study aimed to use electrodes comprising different transition metal oxides to generate oxidants for wastewater treatment, including those with mesoporotic, nanoparticulate, and nanotubular shapes to increase the coverage homogeneities of the transition metal oxides, reduce the cost and reuse the electrodes, achieve good reproducibility, and achieve the highest electrical conductivity and electroactive surface area to increase the lifetime of each modified surface for removal of organic pollutants via simple, green, and efficient methods.

Semiconducting polymers are a fascinating class of materials, both fundamentally and because of their broad applicability in electronics, photovoltaics, display technology and bioelectronics. Relatively few attempts have been made to explore the properties of individual polymer chains, however, and those studies have led to a broad range of observations that can be difficult to reconcile. Here we discuss these measurements with attention to the differences in experimental configurations that may underlie the breadth of experimental reports.

Heterogeneous electro-Fenton (EF) using solid catalysts has emerged as a robust advanced oxidation process for wastewater treatment, capitalizing on the advantages of in-situ oxidant generation, minimal iron sludge production, and a wide pH working window. However, synthetic iron-based catalysts face great challenges in practical application due to their high cost and the risk of secondary pollution. In contrast, the use of natural minerals as catalysts has emerged as a promising alternative owing to their cost-effectiveness, abundance, and eco-friendliness natures. Herein, a summary of the application of natural iron and clay minerals in EF is provided, focusing on the performance, catalytic mechanisms, as well as challenges and perspectives for large-scale application.

The use of waste biomass as a precursor for carbon electrodes in electrochemical water treatment not only offers a resourceful solution to waste management challenges but also constitutes a substantial contribution to the circular economy. This study critically reviews recent advancements in utilizing waste biomass derived carbon materials for electrochemical water treatment, focusing on applications like electrochemical advanced oxidation processes (e-AOPs) and capacitive deionization. The versatility of carbon materials, with characteristics such as extensive specific surface areas, high electrical conductivity, and tunable hydrophobicity, positions them as pivotal for various electrochemical applications. This short review extends to bioelectrochemical systems (BES), highlighting the potential of waste-derived carbon materials to enhance BES electrode efficiency while significantly reducing manufacturing costs. The comprehensive assessment of recent developments provides insights into strengths and weaknesses in the use of these materials and future research directions for optimizing electro/bioelectrochemical water treatment processes on a broader scale.

The electrosynthesis of organonitrogen compounds via co-reduction of carbon dioxide (CO₂) and nitrogenous molecules is regarded as a promising green technology for sustainable and reliable chemical production. Although many researchers have reported on electrochemical C–N coupling reactions, these reactions are still insufficient for use in the commercial industry. In this work, we provide a comprehensive review of the fundamental reaction mechanism of electrochemical C–N coupling and strategies for improving the electrosynthesis of organonitrogen compounds. Additionally, we discuss the current challenges, extended electrochemical coupling reactions, and future roadmaps of electrochemical C–N coupling reactions. This review will strongly enhance the understanding of electrochemical C–N coupling reactions and propose a way forward for the electrosynthesis of organonitrogen compounds.

The urgent demand on net-zero emissions urges solutions for sustainable energy and chemical processes. Electrochemical CO₂ reduction stands as a promising avenue in this pursuit, leveraging renewable energy sources to convert CO₂ and H₂O into valuable chemicals and fuels. Although fundamental knowledges have been acquired by the intensive research efforts for the last decades, challenges persist, particularly in achieving high activity, selectivity, and long-term stability for commercialization of the technology. Addressing these challenges, recent investigations highlight the pivotal role of engineered catalyst microenvironments relating to mass and ion transportation. This review explores the impacts of leveraging conductive polymers in tailoring the catalyst microenvironments, thereby enhancing activity, selectivity, and long-term stability and offers valuable insights for advancing its technologies.

The quantitative modeling of voltammograms obtained with molecular redox catalysts is important for mechanistic studies and benchmarking. Most kinetic models developed for that purpose were based on unidirectional reaction mechanisms, but many redox enzymes work in both directions of the reaction, and chemists have recently successfully designed bidirectional, synthetic, molecular catalysts. An important conclusion from recent work is that unidirectional kinetic models should not be used to interpret bidirectional electrochemical responses. Understanding the latter will require much more work than simply adapting unidirectional models.

Examples of electrochemistry directly assisting in the upvaluing of waste materials are known for condensation polymers, which can be solvolyzed into electrochemically active species, and for self-immolative polymers, whose degradation can be triggered by a redox mediator. Polyolefins (e.g. polyethylene, polypropylene) must first be degraded thermochemically into diacid intermediates, which can then be electrochemically reverted into unsaturated monomers. Electrochemical processes may be of most use for detecting and destroying microplastics, but the process economics have yet to be demonstrated.

This review focuses on the extraction of lithium-ions (Li⁺) from the cathode of spent lithium-ion batteries (SLIB) and application of the delithiated cathode in catalytic reactions. Li⁺ has been extracted from SLIB through electrochemical and chemical leaching methods. Despite challenges for extraction of Li⁺, delithiated cathode materials demonstrate substantial catalytic efficiency in water electrolysis, dye photodegradation, and photoelectrochemical applications. This enhanced catalytic performance is attributable to the favorable catalytic properties of the transition metal oxide components and numerous catalytically active defects and oxygen vacancies formed by delithiation. The findings underscore the potential of recycling SLIBs into valuable catalysts for environmental and energy-related applications, emphasizing the transformation of waste into resource through efficient material reutilization.

Ammonia production, mostly for use in fertilizers, currently consumes up to 2% of the world's energy production and accounts for more than 1.6% of global CO₂ emissions. Hence, it is essential to develop a sustainable and eco-friendly process for NH₃ synthesis. To date, various synthetic techniques have been developed under mild operation conditions. Among them, electrochemical nitrogen reduction reaction (ENRR) allows the direct conversion of atmospheric N₂ into NH₃ from renewables, offering various advantages, So far, most ENRR have been carried out in aqueous electrolytes. However the faradaic efficiency is usually low in such electrolytes, because water or proton reduction to hydrogen competes with nitrogen reduction. Compared to aqueous electrolytes, non-aqueous electrolytes show high electrochemical stability, increased solubility of N₂, high selectivity, promoting the ENRR over hydrogen evolution-reactions, hence improving Faradaic efficiency. However, a comprehensive understanding of ENRR in non-aqueous electrolytes remains inadequate, and challenges such as poor selectivity, low current density, and low energy efficiency still remain in practical implementation. In this review, we summarize the recent progress of ENRR in non-aqueous electrolytes. Some technical challenges arising in this field are highlighted and assessed. In the final part, the perspectives are proposed for future research and commercial practice.