A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources

Cannabis sativa L., a low-cost, fast-growing herbaceous plant, is seeing a resurgence in widespread cultivation as a result of new policies and product drive. Its biodegradable and environmentally benign nature coupled with its high specific surface area and three-dimensional hierarchal structure makes it an excellent candidate for use as a biomass-derived carbon material for electrochemical power sources. It is proposed that this ‘wonder crop’ could have an important role in the energy transition by providing high-functioning carbon-based materials for electrochemistry. In this article, all instances of C. sativa usage in batteries, fuel cells and supercapacitors are discussed with a focus on highlighting the high capacity, rate capability, capacitance, current density and half-wave potential that can be achieved with its utilisation in the field

Meat Quality Assessment by Electronic Nose (Machine Olfaction Technology)

Over the last twenty years, newly developed chemical sensor systems (so called “electronic noses”) have made odor analyses possible. These systems involve various types of electronic chemical gas sensors with partial specificity, as well as suitable statistical methods enabling the recognition of complex odors. As commercial instruments have become available, a substantial increase in research into the application of electronic noses in the evaluation of volatile compounds in food, cosmetic and other items of everyday life is observed. At present, the commercial gas sensor technologies comprise metal oxide semiconductors, metal oxide semiconductor field effect transistors, organic conducting polymers, and piezoelectric crystal sensors. Further sensors based on fibreoptic, electrochemical and bi-metal principles are still in the developmental stage. Statistical analysis techniques range from simple graphical evaluation to multivariate analysis such as artificial neural network and radial basis function. The introduction of electronic noses into the area of food is envisaged for quality control, process monitoring, freshness evaluation, shelf-life investigation and authenticity assessment. Considerable work has already been carried out on meat, grains, coffee, mushrooms, cheese, sugar, fish, beer and other beverages, as well as on the odor quality evaluation of food packaging material. This paper describes the applications of these systems for meat quality assessment, where fast detection methods are essential for appropriate product management. The results suggest the possibility of using this new technology in meat handling

Interpreting signals from an array of non-specific piezoelectric chemical sensors

Pattern recognition methods were tested using a gas sensor array consisting of eight interchangeable quartz crystals coated with different sorbent layers. The system is designed in such a way as to allow headspace sampling from a jar or vial. Using a two-sample t-test the two sampling methods were found to be significantly different at the 95% confidence level. It was found that the application of principal component analysis, multivariate analysis of variance and discriminant function analysis to the gradient of the initial responses and over-all response magnitudes allowed hexane, o-xylene, toluene, dodecane and tetradecane to be distinguished

Transition Metal Doped Cannabis Catalysts for the Oxygen Reduction Reaction in Hydrogen Fuel Cells

The global climate crisis demands a rapid uptake of alternatives to fossil fuels to alleviate further damage to the planet. To this end, supercapacitors, batteries and fuel cells have been identified as critical enabling technologies to overhaul the current energy system. As the demand for these energy storage and conversion devices increases, so does the need to produce sustainable, low-cost and high-performing components for them. Currently, platinum is used to catalyse the sluggish oxygen reduction reaction (ORR) in hydrogen fuel cells. It is generally deposited on a carbon support and forms an electrode that is vital in determining electrochemical performance (namely activity and durability); however, this presents a two-pronged challenge. Traditionally, the carbon used is synthesised via energy-intensive and time-consuming processes involving the incomplete combustion of heavy petroleum products or coal. Secondly, platinum scarcity lends to issues of high cost, which is often ascribed to being the largest hindrance in large-scale commercialisation of this technology. To mitigate these issues, an electrocatalyst based on transition metals and a biomass precursor can be effectively used instead.1 A very promising biomass precursor is hemp. Also known as industrial hemp, it is one of two strains of the cannabis plant. It is one of the oldest domesticated crops in the world, known for its sustainability, high yield and ability to grow on marginal land with low water and pesticide requirements. It is carbon-negative, low-cost and biodegradable - making it the ideal choice in the current climate crisis. Through thermal carbonisation and activation, it yields 3-dimensional hierarchical structures with high conductivity, surface area and porosity.2 Here we report on using nitrogen, iron and cobalt together with cannabis-derived carbon to produce a high functioning and low-cost electrocatalyst to replace Pt/C at the cathode, as shown by a suite of characterisation and electrochemical techniques. With a uniform mesoporous texture and good distribution of metal species, the material displays properties beneficial to catalysing the ORR with a much lower environmental and monetary cost than traditional Pt/C. This forms an excellent basis for further work in this field to achieve the overarching goals of high performance coupled with environmental sustainability. Borghei M., Lehtonen J., Liu L. and Rojas O. J. 2018 Advanced Biomass-Derived Electrocatalysts for the Oxygen Reduction Reaction. Adv. Mater. 30 1703691 Rana Z. I., Shah A. R., Llewellyn A. V., Mazloomian K., McAlernon P., Miller T. S., Cullen P. L., Shearing P.R. and Brett D. J. L. B. 2022 A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources. Curr. Opin. Electrochem. 31 100860 </jats:p

A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources

Cannabis sativa L., a low-cost, fast-growing herbaceous plant, is seeing a resurgence in widespread cultivation as a result of new policies and product drive. Its biodegradable and environmentally benign nature coupled with its high specific surface area and three-dimensional hierarchal structure makes it an excellent candidate for use as a biomass-derived carbon material for electrochemical power sources. It is proposed that this ‘wonder crop’ could have an important role in the energy transition by providing high-functioning carbon-based materials for electrochemistry. In this article, all instances of C. sativa usage in batteries, fuel cells and supercapacitors are discussed with a focus on highlighting the high capacity, rate capability, capacitance, current density and half-wave potential that can be achieved with its utilisation in the field

A novel SON2-based similarity index and its application for the rationalization of river water quality monitoring network

In this paper, a novel self-organizing network (SON) based similarity index and its application for the optimization of sampling locations in an existing river water quality monitoring network (WQMN) is presented. A rationalization of the River Danube WQMN on its stretch through Serbia was performed using the proposed SON2-based similarity index. A high-dimensional dataset was used, which is composed of 18 water quality parameters that were collected during the period 2002-2010 at 17 monitoring locations. The SON-based seasonal classification that divides 12months into the cold, moderate, and warm seasons was employed, whereas its second application on each seasonal class yielded subclasses that were used to compare the monitoring locations. The obtained SON2-based similarity index can be utilized for analysing seasonal variations, as well as overall similarities among neighbouring sites. Based on the calculated similarities of locations and characteristics of the River Danube basin a rationalized WQMN, which uses 30% less monitoring sites, has been proposed