The efficient production of hydrogen through water electrolysis requires stable, high-performance and rather cost-effective electrocatalysts to promote the hydrogen evolution reaction (HER).

A controllable preparation strategy for high-efficiency Ni–Cu catalysts with specific morphology.

Building electrochemical activity into ionic liquids extends their practical potential beyond acting as inert electrolytes or solvents to being multi-functional electro-materials with a myriad of application including in energy harvesting and storage. This review looks back briefly to their origins and goes on to outline and discuss recent important developments in the field. The prospect for these useful new materials is also discussed.

Simple ionic liquids exhibit unique physical and chemicalproperties that make them very useful for deployment in electrochemicaldevices such as solvent-free electrolytes in capacitors and batteries.However, incorporating redox functionality into ionic liquidstructures opens up in situ faradaic electrochemistry which allows accessto a large array of new electrochemical applications reliant uponheterogeneous or homogenous electron-transfer processes. This paperpresents and discusses the opportunities and challenges for these typesof electro-materials across a myriad of applications by consideringexemplar quinone-functionalised ionic liquids.

The electrochemical carboxylation of a range of substituted benzophenones was studied in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid (IL, ([Bmpy] [NTf2])). As expected, the aromatic carbonyls exhibited electrochemical reversibility for the first reduction to the radical anion at potentials which were a function of the sum of their Hammett substituent constants (Sigma sigma). However, in the presence of CO2, the electrochemical reversibility was lost and positive shifts in reduction potentials were observed which were indicative of post-electron transfer chemical reaction which has been attributable to the nucleophilic radical anion/CO2 coupling reaction. Analysis of the positive potential shift a function of sweep rate (nu) indicated that the mechanism is either ECE or DISP1, or mixed ECE/DISP1. Also from the potential shift with nu, an apparent rate constant (k(app)), and a pseudo-first order rate constant (k(1)), for the coupling reaction was determined and compared to molecular solvent where the rate is over two orders of magnitude lower in IL compared to dimethylforrnamide (DMF). The low polarity of the IL compared to DMF appears to be the cause of slow kinetics. Finally, plots of k(app) vs. Sigma sigma were strictly linear indicating that IL does not preferentially interact with any of the electrogenerated radical anions thus implying that the electrocarboxylation reaction may be a useful probe of IL environments and structure on radical anion reactions.

The unique physical and chemical properties of conventional room temperature ionic liquids (RTILs) render them highly deployable materials in electrochemical devices performing functions such as solvent-free electrolytes in capacitors, batteries and sensors. However, these non-faradaic applications can be complimented by incorporating faradaic redox functionality into the ionic liquid structure which facilitates access to a large array of new electrochemical applications such as dye sensitised solar cells, redox batteries, hydrid capacitors and selective amperometric sensor applications which are all reliant on heterogeneous or homogenous electron-transfer processes. This paper presents and discuses some examples of redox active ionic liquids base on the ferri-/ferro-functionality. These functional electromaterials which are already known [Ref. [18]] exhibit simple reversible one-electron electrochemistry at very negative potentials (by at least -1 V relative to aqueous systems) in anhydrous media. Glass transition temperatures lower than -50 degrees C were also observed along with an overall thermal stability up to at least 400 degrees C under dry N-2 atmosphere conditions. Opportunities and challenges for these types of electro-materials are discussed. (C) 2017 Elsevier Ltd. All rights reserved.

The first page of this article is displayed as the abstract.

Carbons are the main electrode materials used in electrochemical capacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alternatives to current state of the art acetonitrile-based electrolytes. Also, in terms of safety and sustainability ionic liquids are attractive electrolyte materials for electrochemical capacitors. In addition, it has been shown that the matching of the carbon pore size with the electrolyte ion size further increases the attainable electric double layer (EDL) capacitance and energy density. The use of pseudocapacitive reactions can significantly increase the attainable energy density, and quinonic-based materials offer a potentially sustainable and cost effective research avenue for both the electrode and the electrolyte. This perspective will provide an overview of the current state of the art research on electrochemical capacitors based on combinations of carbons, ionic liquids and quinonic compounds, highlighting performances and challenges and discussing possible future research avenues. In this regard, current interest is mainly focused on strategies which may ultimately lead to commercially competitive sustainable high performance electrochemical capacitors for different applications including those requiring mechanical flexibility and biocompatibility.

Toru H. Okabe, Olga Kuzmina, John M. Slattery, Cairong Jiang, Tim Sudmeier, Linpo Yu, Han Wang, Wei Xiao, Liang Xu, Xiangling Yue, Yiyang Kong, Andrew Doherty, Geir Martin Haarberg, Shuqiang Jiao, Qian Xu, Hongmin Zhu, Dihua Wang, Paul Madden, Daniel Cooper, Kathie McGregor, Chaohui Wei, Binjie Hu, Andrew Mount, John Irvine, Ali Kamali, Babak Khalaghi, Xianbo Jin, Yingjun Liu, George Zheng Chen, Xingli Zou, Gang Chen, Ye Liu, Majd Eshtaya, Derek Fray and Yating Yuan

Tim Sudmeier opened a general discussion of the paper by Yasuhiko Ito: Firstly, I would like to thank you, Prof. Ito, for your very inspiring talk and for all of your work in this field. I have a question regarding your advanced-type ammonia synthesis cell that consists of two melts (chloride a

Densely packed interfacial nanoparticle films form spontaneously when aqueous Ag colloid is shaken with CH2Cl2 in the presence of a "promoter" such as 10(-4) mol dm(-3) tetrabutylammonium nitrate (TBA(+)NO3(-)), which induces rapid self-assembly of the nanoparticles at the liquid/liquid interface without adsorbing onto their surfaces. The particles within these reflective, metal-like liquid films (MeLLFs) are optically coupled and give strong SERS enhancement, similar to that obtained for the same colloid aggregated with optimized concentration of metal salt. However, unlike aggregated colloids their structure means they do not sediment out of solution so they give SERS spectra that are stable for >20 h) and have good uniformity (relative standard deviation in absolute intensity over 1 mm(2) array of 25 points was 1.1%). Since the films lie at the aqueous/organic interface they are open to adsorption of analytes from either of the phases and can be probed in situ to detect both water- and nonwater-soluble analytes. The detection limit for mercaptobenzoic acid (MBA) added to the organic layer was found to be <2 ppb. These materials therefore combine many of the best features of both patterned surfaces and metal colloids for quantitative SERS analysis.

Two electrochemical techniques have been used to measure the pK(a) of N-bases in several ionic liquids (ILs). The first method corresponds to a potentiometric titration of a strong acid with the N-base using a platinized Pt indicator electrode immersed in the IL solution and maintained under dihydrogen atmosphere via gas bubbling. The second approach involves performing cyclic voltammetry at a platinized Pt electrode in a solution containing both strong acid and the conjugate weak acid of the N-base. Values of pK(a) obtained by one or the other approach are in good agreement with each other. The experimental data clearly demonstrated that acid/base chemistry in ILs is similar to that observed in molecular nonaqueous solvents; i.e., the relative strengths of the bases were in the right order and spaced (ΔpK(a)). It was also observed that the strength of N-bases is highly dependent on the anion of the ionic liquid; this observation indicates that pH-dependent reactions could be controlled by the appropriate choice of anion for bulk ILs or as an added co-ion to bulk IL.

A conveniently assembled, sensitive and fast-responding membrane free amperometric sensor is described for the detection of nitrogen oxides in gaseous atmospheres which exploits some profitable properties of room temperature ionic liquids (RTILs), such as high electrical conductivity, negligible vapor pressure and good thermal stability. It consists of three Pt wires piercing through a Teflon rod, whose exposed head is coated with a steadily adhesive thin RTIL film assuring the necessary electrical conductivity among the electrodes. The negligible vapor pressure of the immobilized RTIL layer makes possible to eliminate the need for the use of membranes, thus avoiding the involvement of a slow limiting step such as analyte permeation. Preliminary voltammetric tests performed at this sensor in gaseous atmospheres proved that the oxidation of NO2 and NO occurs at very close potentials, thus allowing effective NOx determinations. Instead, other atmospheric components able to act as possible interfering species (CO, H2S and SO2) were found to undergo oxidation only at quite higher potentials. The performance of this device was assayed under flowing conditions on synthetic nitrogen atmospheres with controlled NOx contents, which was changed in a wide range (0.01103 ppm v/v). At room temperature, repeatable (+/- 3.9%) and linearly dependent current signals were recorded, allowing a detection limit of 0.96 ppb v/v to be inferred. At higher temperatures (100 degrees C) a lower detection limit (0.55 ppb v/v) could be instead estimated. The possibility of using this sensor for monitoring NOx in reduced pressure atmospheres was also assayed.

Rising costs and green environmental concerns have focused attention on more efficient way of producing chemical products. Room temperature ionic liquids (RTILs), especially in combination with electrochemical activation, provide promise of reduction pollution in processing because of their recyclability and low vapour loss factors. The fundamental and applied aspects of electrolytic processing in ionic liquid media are discussed using data from various direct and catalytic redox processes. It is shown that ionic liquids are potentially very useful for performing important redox transformations, for example alcohol oxidations, carboxylations and CO 2 capture. These results indicated that electrolytic transformations in RTIL media are feasible which present opportunities for developing new real chemical processing applications. The opportunities and challenges for electrochemical engineers in this field are outlined and discussed. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.

The interpretation of resilience in asset management is significantly different at the conceptual and design stages of new build compared to the application to existing infrastructure. An asset manager needs to balance the performance expectations of customers and stakeholders with the residual capacity of the existing system. This paper explains how enhanced data collection and analysis techniques have enabled the UK railway network to optimise whole-industry costs at the wheel-rail interface, maximise system capability by use of spare capacity and analyse implications of climatic conditions and long-term changes. It also shows how the consequences of change across a system interface can become apparent in accelerated infrastructure deterioration. The recognition of these interfaces and understanding the interactions of key factors have led to a more resilient railway network and optimised asset preservation.

A conveniently assembled membrane-free amperometric sensor is proposed for the detection of oxygen in gaseous atmospheres which exploits some profitable properties of room temperature ionic liquids (RTILs), such as their high electrical conductivity, negligible vapour pressure and good thermal stability. The advantages offered by this type of medium were increased by adding small amounts of a further low melting salt bearing a quinone moiety, which allowed the reduction of O-2 to occur through an electrocatalytic pathway taking place at quite lower potentials than those required by its direct reduction. The rate constant (14,160 +/- 370 M-1 s(-1)) of this electrocatalytic process was determined by resorting to linear sweep voltammetric measurements. The performance of this device was assayed under both flowing and static stop-flow conditions on synthetic O-2 + N-2 atmospheres with a controlled oxygen content, which was changed in a wide range (200-10(6) ppm v/v). At room temperature, repeatable (+/- 2.7%) and linearly dependent current signals were recorded, allowing a detection limit of 140 ppm v/v (equivalent to 6.2 x 10(-6) mol of O-2 per L of gaseous atmosphere) to be inferred. At higher temperatures (100 degrees C) a lower detection limit (10 ppm v/v, equivalent to 4.5 x 10(-7) mol of O-2 per L of gaseous atmosphere) could be instead estimated. The possibility of profiting from this sensor for monitoring oxygen under reduced pressure was also assayed, in view of the growing importance attached to the evaluation of residual O-2 in food packaging under vacuum or controlled atmospheres. (C) 2012 Elsevier B.V. All rights reserved.

Biosensors have been prepared by modification of glassy carbon electrodes with functionalised multi-walled carbon nanotubes (MWCNT) dispersed in the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethane)sulfonimide (BmimNTF(2)) and with lipase cross-linked with glutaraldehyde. The biosensor was applied to the determination of olive oil triglycerides by cyclic voltammetry. A phosphate buffer (pH 7.0)/BmimNO(3) mixture is a better electrolyte than aqueous buffer alone. The response signal in the buffer-BmimNO(3) mixture was found to increase with the number of cycles until a constant current was achieved. The calibration curve obtained exhibited a sigmoid shape and a four-parameter model was used to fit the data which gave a limit of detection of 0.11 mu g mL(-1). Close inspection of such calibration curves showed two distinct linear regions indicating changes in the mechanism of the electrochemical response. Overall, the oxidative analytical response was found to be due to phenolic compounds present in the olive oil, released in the presence of lipase, rather than due to triglycerides per se. It was also found that there were no interferences from either cholesterol or glycerol. A possible mechanism of olive oil determination at a MWCNT-BmimNTF(2)/LiP biosensor is proposed. (C) 2011 Elsevier B.V. All rights reserved.