Don Kirk

• BASc, MASc, PhD
• Professor (Full) at University of Toronto

Quaternary NiCoMoB electrocatalysts exhibited significantly enhanced OER performance compared to their ternary NiCoMo and NiCoB counterparts. An optimal Mo/B ratio of 1 (NiCoMoyBy) demonstrated a superior OER activity, attributed to a balance between the electronic and structural contributions from Mo and B, maximizing the electrocatalytic site den...

This study investigated the electrochemical properties of supercapacitors by pre-modifying thick birch biochar monoliths with FeCl3 or C6H5FeO7 solutions prior to wood pyrolysis. The pre-modification introduced iron species to the surface, promoting the specific surface area, charge-stored species, and surface functionalities, which enhanced the gr...

The performance of supercapacitors is significantly influenced by both the nature and the concentration of the electrolyte employed. This study investigates the impact of a neutral electrolyte on the electrochemical properties of the maple-derived monolithic wood biochar (MWB)–sodium sulfate (Na2SO4) supercapacitor. The goal is to determine if a ne...

Quickly discharged supercapacitors are often found to show voltages that increase with time ranging from minutes to several hours. People attribute this to the special structure of the supercapacitor; however, we propose an alternative explanation. A physical model was developed to explain the phenomenon and further reveal the working mechanism of...

Background It has long been recognized that the presence of azo metal complex dyes and their non-complexed counterparts in wastewaters, which is due to their manufacturing and use in the textile industries, renders natural waterways intensely coloured, and is therefore aesthetically unacceptable. Azo dye moieties are also known to be precursors of...

In this work, the authors attempt to interpret the visible, infrared and Raman spectra of ferrate(VI) by means of theoretical physical-inorganic chemistry and historical highlights in this field of interest. In addition, the sacrificial decomposition of ferrate(VI) during water treatment will also be discussed together with a brief mention of how R...

X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy (UPS) were performed on as-received analytical grade Co3O4 nanoparticles (<50 nm). Co3O4 has proven to be an extremely useful material for a wide variety of applications. This report provides a detailed photoelectron spectroscopy investigation of Co3O4 to aid with identific...

X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy (UPS) were performed on as-received analytical grade Co(OH)2 powder. The presence of Co(OH)2 within renewable energy applications is important for enhancing activity. This report provides a detailed photoelectron spectroscopy investigation such that Co(OH)2 can be properly...

The use of novel anion exchange membranes (AEM) are of interest in a wide variety of electrochemical systems. On particular interest is in alkaline water electrolysers since it eliminates the aqueous KOH electrolyte and can provide improved form factors and much higher current densities that rival proton exchange membrane (PEM) electrolysers. ¹ The...

Trees are crucial to humankind's survival, releasing the oxygen we breathe, growing the fruits we eat, and supplying wood to build and warm our shelters. Heating wood at 300°C‐800°C with little or no oxygen creates wood biochar, a carbonaceous product. Wood biochar monoliths have a continuous carbon matrix and morphological features that resemble a...

X-ray photoelectron spectroscopy (XPS) was performed to characterize the air formed Y2O3 surface layer on yttrium powder. Prior to XPS measurements, x-ray diffraction was performed to confirm the presence of Y2O3. The air formed Y2O3 displayed little residual metallic Y remaining at the surface with contamination from hydrocarbons. In addition to t...

Amorphous Ni 79.2−x Co x Nb 12.5 Y 8.3 (x = 0 and 5 at %) nanoparticles were produced through a two-stage ball milling process for use as electrocatalysts in the alkaline oxygen evolution reaction (OER). Cyclic voltammetry demonstrated that these amorphous alloys have excellent long-term cyclic durability when compared to crystalline Ni and Ni 95 C...

X-ray photoelectron spectroscopy was performed on as-received analytical grade Y(OH)3 powder. This report provides a detailed photoelectron spectroscopy investigation such that Y(OH)3 can be properly identified in a non-destructive manner from Y2O3. In addition to the survey scan, detailed charge corrected scans for Y 3s, Y 3p, Y 4s, Y 4p, O 1s, O...

Biochar is traditionally used as solid fuel and for soil amendment where its electrical conductivity is largely irrelevant and unexplored. However, electrical conductivity is critical to biochar’s performance in new applications such as supercapacitor energy storage and capacitive deionization of water. In this study, sugar maple and white pine wer...

Monolithic wood biocarbon is an emerging functional material for energy and environmental applications. Its water permeability directly affects its performance but hasn't been quantified. Via slow pyrolysis to 1000 °C, biocarbon monoliths were prepared from five wood precursors -two hardwoods: sugar maple (acer saccharum) and balsa (ochroma pyramid...

Amorphous Ni79.2Nb12.5Y8.3 and Ni81.3Nb6.3Y12.5 nanoparticles were synthesized using cryogenic mechanical alloying followed by surfactant-assisted high energy ball milling (SA-HEBM). These alloys were tested towards the hydrogen evolution reaction (HER) along with pure crystalline Ni and Ni5Y nanoparticles also produced through SA-HEBM. This two-st...

Plastic deformation of metallic glasses under compression proceeds through sudden stress drops and accumulations known as serration or avalanche events. Experimental studies have suggested that this occurs by stick-slip behaviour of weak spots, while the atomistic structural origins underlying this phenomenon have remained unclear. In this study, w...

Both morphological structure and chemical composition are indispensable factors for the design and fabrication of high-performance electromagnetic (EM) wave absorbers. Herein, we prepare a porous carbon composite material with high surface area by using recycled fluid coke as starting material via an alkaline activation process. The minimum reflect...

Biocarbon is a carbon-rich, porous material derived from biomass, and a promising electrode material for supercapacitors. Supercapacitors are fast-charging, long-lasting energy storage devices that have high power density and low energy density, relative to batteries. Many of the most recent efforts to raise the energy density of supercapacitors fo...

Amorphous Ni79.2-xCoxNb12.5Y8.3 (x = 0, 5 at.%) alloys were synthesized using cryogenic mechanical alloying and evaluated as catalyst for the oxygen evolution reaction (OER) in alkaline media using cyclic voltammetry and Tafel measurements. Electrochemical testing showed that the amorphous alloys possessed lower Tafel values for the OER compared to...

For the first time, the recovery of copper from Cu(II)-EDTA complexes in waste streams, which originated from electroless plating of printed circuit boards (PCB), is optimized with respect to the consumption of electrical energy required for the separation process. To narrate the sequence of arguments which result in this minimization of energy exp...

In this article experimentation to establish the feasibility of a chemical reaction between free radical chlorine dioxide ClO2 and chelated complexes of Co2+, Ni2+ and Cu2+ with citric acid (C6H8O7) and ethylenediaminetetraacetic acid (EDTA, C10H16N2O8) as ligands, leading to the stoichiometric recovery of the metallic ions, is described. The proce...

This short narrative focuses on the essence of the electrochemical potential E h vs. pH relationships of the simplest plutonium species in aquatic environments. Of the many oxidation states reported of plutonium, only those with potentials within the limits of stability of water are expected to be thermodynamically stable. More importantly, the sol...

The electrochemical synthesis of glycerol carbonate from glycerol and potassium carbonate enables utilizing electrical power under mild reaction conditions to upgrade the glycerol waste into valuable glycerol carbonate while consuming carbon dioxide. To further scale up the bench-scale process for industrial application, understanding the reaction...

With the increasing drive towards renewable energy sources, the need for further development in electrical energy storage is apparent. As it stands, the temporal misalignment between energy generation and electrical use or demand gives rise to grid-scale issues that can only be addressed by the de-coupling of energy generation and energy demand [1]...

Introduction: The recent development of anion exchange membranes (AEM) has renewed interest in alkaline water electrolysis for large-scale production of hydrogen gas. These systems can achieve current densities comparable to PEM-based systems while enabling the use of non-PGMs as catalyst materials. New electrocatalysts are required to interface wi...

Traditional alkaline water electrolysis has been successful industrially because of the use of low cost, stable, nickel based materials as electrocatalysts. The major drawback to these systems is that they use aqueous KOH as the electrolyte which is not desirable from a corrosion and packaging perspective. The use of novel anion exchange membranes...

An amorphous alloy Ni74.2Co5Nb12.5Y8.3 was synthesized using cryogenic mechanical alloying and evaluated as a catalyst for the oxygen evolution reaction (OER) in alkaline media using cyclic voltammetry and Tafel measurements. Electrochemical testing showed that the amorphous alloy possessed a lower Tafel slope and enhanced kinetics for the OER comp...

Proton-conducting polymer electrolytes consisting of borotungstic acid (BWA) and polyacrylamide (PAM) were developed. The addition of BWA to PAM progressively improved the electrolyte conductivity. The as-fabricated BWA-PAM electrolyte exhibited a high ionic conductivity of ca. 27 mS cm⁻¹, but suffered from low shelf life due to poor water retentio...

This study investigates biochar supercapacitor electrodes made several times larger than those in commercial application, using both thick monolithic and powder thin film structures. Slow-pyrolysis of wood precursors produces carbonized biochar monoliths which retain the internal structures of biomass. While this natural network of transportation c...

Porous SiC ceramics were synthesized for its potential electromagnetic interference (EMI) shielding application, with the utilization of a biomass material as the porous template and carbon precursor. A silicon infiltration process was conducted in the temperature range of 1400–1600 °C with the absence of any catalyst to produce the porous SiC cera...

Electrochemical double-layer capacitors are promising energy storage devices with high power density, moderate energy density, rapid charging rates, and high cycle life. In order to maximize energy density, highly porous carbon materials are often incorporated in the electrodes. The structure of the porous carbon network is critical to ensure high...

Porous carbon is a common electrode material used in electrochemical double-layer capacitors, in which energy is stored by physical adsorption of electrolyte ions on the carbon’s surface forming an electrical double layer (EDL). However, due to the complex nanoporous network of carbon materials, it is difficult to characterize the EDL structure. Th...

A novel label-free impedimetric immunosensor for the quantitative detection of aflatoxin B1 (AFB1) was developed based on orientated staphylococcus protein A (SPA) modified gold three dimensional nanotube ensembles (3DTNEEs) which consisted of gold nanotubes fabricated by combining the technologies of template synthesis and controlled chemical etch...

The parallel plate electrolyzer is of interest in electrochemical applications. However, the modelling of an electrolyzer often involves numerical integration or use of infinite series that is computationally expensive. Using some simplifying assumptions, a novel analytical solution to the governing equation could be obtained using a similarity tra...

Supercapacitors are an upcoming, high power density energy storage technology. Unlike in batteries, energy is stored physically through the adsorption of oppositely charged ions to a surface. Electrode materials that facilitate this process have high conductivity, extensive porosity, and high specific surface area. Porous carbon powders are used co...

Introduction Alkaline electrolysis with anionic exchange membranes has been shown to be a highly promising technology to produce hydrogen gas. This zero gap system does not require a liquid electrolyte and can utilize non-precious metal electrocatalyst materials. As such, it is possible to produce a low cost and energy efficient water electrolyzer...

The growing biodiesel industry leads to an excess production of glycerol by-product which is of low value but costly to store or dispose because glycerol is not suitable as fuel due to its sooty flame while its discharge to water leads to eutrophication. On the other hand, industrial carbon dioxide could be readily captured by scrubbing with potass...

Bulk metallic glasses (BMGs) contain a unique combination of enhanced mechanical and chemical properties due to the absence of crystalline features, but their machining processes are still being developed. Electrochemical micromachining (ECMM) with microtool electrodes is a promising technique for microshaping BMGs without the use of elevated tempe...

Monolithic biochar is explored as electrode material in supercapacitor – a fast-charging, long-lasting energy storage device. Electrical conductivity of electrode is critical to supercapacitor's performance. Traditionally, biochar is used as a solid fuel for combustion where electrical conductivity is largely irrelevant and ignored. This work explo...

One strategy to improve the energy density of electrochemical double-layer capacitors is to maximize the capacitance per unit surface area. However, due to the intercoupled relationship between surface area and pore size distribution, the effect of pore size on capacitance remains unclear. In this study, two samples prepared from the same raw mater...

Increasing research effort has been made aiming at developing electromagnetic (EM) wave absorbing materials with high absorption performance. An ideal EM absorber should be relatively light-weight, thermally stable, capable of absorbing wide EM frequency, and cost effective. As a dielectric material, silicon carbide (SiC) has great potential with r...

Stainless steel with chromium carbide coating is an ideal candidate for bipolar plates. However, the coating still cannot resist the corrosion of a proton exchange membrane fuel cell (PEMFC) environment. In this work, the corrosion kinetics of 316L stainless steel with chromium carbide is investigated in simulated PEMFC cathodic environment by comb...

SnO2-Sb2O5 coated Ti anodes can be used in the anodic oxidation of organic compounds for wastewater treatment. In this work, different SnO2-Sb2O5 anode compositions were fabricated using various techniques, such that the composition of the coating was varied from a SnO2-based to a Sb2O5 based material. These anodes were tested for the activity in t...

Electrochemical double-layer capacitors (EDLCs) store energy at the interface of the electrode and electrolyte, known as the electrical double layer. One of the challenges facing EDLC technology is their moderate energy density compared to batteries and fuel cells. Therefore, improving EDLC performance requires identification of the key electrode a...

The technical field generally relates to CO2 capture and utilization to produce chemical compounds, such as glycerol carbonate.

Porous silicon carbide (SiC) material was synthesized by a novel technique, which incorporates the natural porous structure of a fruit, in particular apple. Its characteristic morphological structure has been difficult to synthesize with traditional materials. The novel porous SiC structure was characterized by scanning electron microscopy, X-ray d...

Arc melting and suction casting was used to prepare (Zr57Ni20Al15Cu8)100 − xNbx bulk metallic glass alloys with Nb concentration ranging from 1.9 to 4.3 at.%. The glass forming ability and crystallization behavior of these alloys were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimet...

The Ti/SnO 2 -Sb 2 O 5 anode is a promising material for the anodic oxidation of organic compounds for the application of wastewater treatment. The material consists of a thin film of Sb-doped SnO 2 on the titanium substrate. The influence of Sb doping on the conductivity of SnO 2 thin films has been well documented, but its effect on the catalysis...

Electrochemical double-layer capacitors (EDLCs) use physical ion adsorption in the capacitive electrical double layer of high specific surface area (SSA) materials to store electrical energy. Previous work shows that the SSA-normalized capacitance increases when pore diameters are less than 1 nm. However, there still remains uncertainty about the c...

The successful fabrication of bulk metallic glasses (BMG) through suction casting based on the existing literature is a difficult task due to the sensitivity of glass-forming ability (GFA) to small changes in processing variables. We report processing challenges and process modifications required in the successful and consistent production of Zr-Cu...

A zinc-air fuel cell, utilizing zinc and atmospheric oxygen as fuel, offers a cheap, environmentally-friendly yet effective alternative for energy storage and production. However, previous studies observed the formation of hydrogen, a source of fire hazard during cell recharge, yet it was unknown whether the hydrogen evolution was significant enoug...

Bulk metallic glasses are a relatively new class of amorphous metal alloy which possess unique mechanical and magnetic properties. The specific concentrations and combinations of alloy elements needed to prevent crystallization during melt quenching remains poorly understood. A correlation between atomic properties that can explain some of the prev...

Electrochemical double-layer capacitors (EDLCs) are emerging energy storage devices that provide high power density and rapid charging rates, with higher energy density than conventional capacitors. Extensive research efforts have been devoted to develop novel, high performing electrode materials to improve device performance, particularly to incre...

A data analysis method was developed for the interpretation of the electrochemical impedance spectra of electrodes with a layered structure. This method was successfully applied to the study of a layered titanium-supported antimony-tin oxide anode material which had an artificial passive layer. The time constant spectrum showed a distribution of re...

An ultrasensitive label free impedimetric immunosensor for AFB1 detection was fabricated based on Poly(o-phenylenediamine) (PoPD) electropolymerized film modified gold three dimensional nanoelectrode ensembles (3DNEEs). The nanoelectrode ensembles were fabricated by template synthesis in track etched polycarbonate (PC) membranes. Scanning electron...

Electrochemical impedance spectroscopy (EIS) is a useful method for characterizing the interfacial characteristics of materials such as a passive layer underneath the surface of a titanium-based metal-oxide anode. Conventionally EIS data were interpreted by fitting them with electrically equivalent circuit. However, this method requires the initial...

This study aims to investigate the effect of microwave heating versus conventional heating for the alkaline hydrolysis of xylan from birch wood to understand the effect of the heating process on the dissolution of wood, the yield of xylan, and the degree of polymerization of the isolated xylan. The results indicate that the rate of wood dissolution...

The in-depth chemistry of a Ti/SnO2-Sb2O5 anode was investigated by X-ray photoelectron spectroscopy combined with ion etching. The coating was found to be composed of multiple layers of tin and titanium oxides and composition gradients at both the oxide-air and oxide-metal interfaces. The existence of such an extensive titanium oxide layer may be...

Alkaline exchange membrane fuel cells (AEMFCs) possesses several important advantages, including facile kinetics at the cathode, using non-precious metal catalyst, wide choice of fuel, and has begun to attract a lot of attention. In this paper, the characteristic of different non-platinum catalysts are introduced. Based on the analysis, binary and...

In order to evaluate the effect of temperature on the performance of supercapacitor using coconut shell activated carbon (AC)/carbon nanotubes (CNTs) as nano-composite electrodes, the supercapacitor's properties were tested in 4mol L-1 KOH solution at 35°C∼60°C. The results indicated, when temperature increased from 35°C to 60°C, the resistance dec...

In order to improve the properties of electrodes based on carbon nanotubes (CNTs), nanocomposite electrodes of CNTs/activated carbon (AC) are prepared. The effect of CNT loadings on the performance of the nanocomposite electrodes is evaluated by electrochemical methods. Scanning electron microscopy images show the CNTs are well dispersed, entwine w...

Antimony-doped tin oxide anodes were fabricated from the thermal decomposition of tin chloride and antimony chloride. The surface and in-depth distribution of elemental compositions were analyzed using photoelectron spectroscopy. The results suggested that during the thermal treatment of the anodes, antimony preferentially was lost by evaporation,...

Introduction The Ti/SnO 2 -Sb 2 O 5 anode was found to be suitable for the electro-oxidation of organics in municipal wastewater, due to its low cost, high efficiency and strong oxidation power ¹ . Similar to other anodes of metal-oxides on titanium, it can be prepared by the thermal decomposition of metal chlorides on a titanium substrate, but thi...

It is increasingly recognized that a significant component of apparent self-discharge in supercapacitors is, in fact, due to charge redistribution. This charge redistribution is due to the limited mobility and hence high resistance of ions moving in the smallest pores of the carbon electrodes. A simple two-branch equivalent circuit has been used to...

A nitroso compound (R-NO) known as a "spin trap" was used to study the production of hydroxyl radicals (OH·) on a Ti/SnO 2-Sb2O5 anode. A linear voltammetry study was conducted on this anode in the presence of this compound, using the rotating disk electrode technique. The results showed that the electrode started to produce (OH·) at 0.7V vs. Ag/Ag...

In response to global environmental challenges, Elementa Group Inc. (Elementa) has developed a pure steam reforming process for Municipal Solid Waste (MSW) and other waste feedstock materials to produce clean and efficient renewable energy. The Elementa technology is a novel patented Waste-to-Gas conversion technology and is based on a unique pure...

Porous activated carbon is an important electrode material for devices such as supercapacitors, batteries and fuel cells. Despite the research and commercialization work that has been carried out, there is still a need to understand some of the fundamental characteristics of the role of activated carbon and the electrolyte in charge storage and ion...

Selenate (SeO42-) is a toxic soluble compound and its presence in the environment should be minimized. Reduction of selenate ions by elemental iron is a promising approach for treating contaminated waters. However, uncertainty exists regarding both the favorable conditions required and the associated mechanisms. In this study, the kinetics and mech...

Supercapacitors are energy storage devices that have the ability to be charged and discharged much faster than batteries but suffer from low energy density. In researching the influence of pore dimensions of activated carbon to increase energy storage, we reported earlier that there can be a significant fraction of charge held in activated carbon t...

A mixed metal-oxide anode material, Ti/SnO2-Sb2O 5, is a candidate electrode for the electro-oxidation of organic compounds for treatment of wastewater. The catalytic efficiency of this material is dependent on both its surface morphology and surface chemistry. The surface chemistry was studied by photoelectron spectroscopy, and correlated with the...

The removal of toxic arsenic species from contaminated waters by zero-valent iron (ZVI) has drawn considerable attention in recent years. In this approach, arsenic ions are mainly removed by adsorption to the iron corrosion products. Reduction to zero-valent arsenic on the ZVI surface is possible in the absence of competing oxidants and can reduce...

This work addresses the discrepancy in the literature regarding the effects of sulfuric acid (H(2)SO(4)) on elemental Hg uptake by activated carbon (AC). H(2)SO(4) in AC substantially increased Hg uptake by absorption particularly in the presence of oxygen. Hg uptake increased with acid amount and temperature exceeding 500 mg-Hg/g-AC after 3 days a...