Promoting hands-on science learning globally with low-cost lab kits through Women Supporting Women in the Sciences.

Women Supporting Women in the Sciences (WS2)-ws2global.org-is an international initiative unifying and supporting graduate- and professional-level women and allies in science, technology, engineering, and mathematics (STEM), while providing outreach to elementary- and secondary-level students. WS2 has been involved in the development of professional development workshops intended to empower university women and promote STEM careers. In their most recent venture, WS2 distributed low-cost physics and materials science lab kits that were designed virtually by international teams. These kits are relevant to elementary and secondary school students across the world, with initial focus on local schools in eastern Africa. In this Backstory, part of the WS2 leadership team (Dr. Joyce Elisadiki, Dr. Cecilia Rolence China, and Dr. Jill Wenderott) discusses how the Lab Kit Initiative came together and highlights outcomes and lessons learned from this project.

Adsorption-capacitive deionization hybrid system with activated carbon of modified potential of zero charge.

In this study water solutions are desalinated with carbon electrodes of modified surface charges. The idea is to endow the electrodes with the ability to physically adsorb salt ions without applying potential so as to save energy. The modification enhanced to decrease the energy consumption of a newly invented adsorption-CDI hybrid system by 19%, since modified activated carbon cell consumed 0.620 (relative error 3.00%) kWh/m3 compared to pristine activated carbon cell which consumed 0.746 (relative error 1.20%) kWh/m3. Further analysis revealed high adsorption capacity of the modified activated carbon electrode cell which exhibited 9.0 (relative error 2.22%) compared to activated carbon cell with 5.3 (relative error 5.66%) mg g-1. These results show the potential of surface modification in adding value to low cost activated carbons for application in CDI.

Towards attaining SDG 6: The opportunities available for capacitive deionization technology to provide clean water to the African population.

The unavailability of clean water caused by population growth, increased industrial activities, and global climate change is a major challenge in many communities. A number of desalination technologies including distillation, reverse osmosis and electrodialysis, have been used to supplement the available water resources. However, these technologies are energy intensive and demand a significant financial commitment. Capacitive deionization (CDI) is an emerging desalination technology which is promising to provide water at a reasonable cost, especially in societies with limited incomes such as those in Africa. The opportunities for CDI to provide clean water to the African population are discussed in this paper. These opportunities include electrosorption at low potential, low energy consumption, large quantities of agricultural wastes for the production of electrode materials, high sunshine irradiation throughout the year, suitability for disinfection and defluoridation and its applications in the removal of heavy metals and emerging pollutants. Due to the existence of numerous enabling conditions, the analysis from this paper demonstrates that CDI can be a dependable method to provide clean water in Africa.

Processing-properties-performance triad relationship in a Washingtonia robusta mesoporous carbon materials-based supercapacitor device.

Two-electrode electrochemical tests provide a close performance approximation to that of an actual supercapacitor device. This study presents mesoporous carbon materials successfully derived from Washingtonia robusta bark (Mexican fan palm) and their electrical performance in a 2-electrode supercapacitor device. The triad relationship among carbon materials "processing, properties, and performance" was comprehensively investigated. X-ray diffraction reveal that amorphousness increases with activating KOH ratio and decreases with both activation time and temperature. Raman spectroscopy shows an increase in structural defects and degree of graphitization with an increase in KOH ratio, temperature and time while transmission electron microscopy shows conversion of aggregated particles to materials with interconnected porosity and subsequent destruction of porosity with an increase in KOH ratio. A nitrogen-sorption study reveals varying trends between BET, micro and mesopore surface areas, however, pore size and volume and hysteresis loop size decreases with KOH ratio and temperature. Electrochemical studies on the other hand reveal that both the specific capacitance and charge-discharge time increase with KOH ratio, temperature and time while both charge transfer and Warburg resistances decrease and the phase angles increases towards the ideal -90° with an increase in KOH ratio, temperature and time. The device fabricated with the HHPB sample prepared at 700 °C, KOH ratio 3 for 60 min attained a specific capacitance of 179.3 and 169 F g-1 at a scan rate of 5 mV s-1 and current density of 0.5 A g-1, respectively, good cycling stability with 95% capacitance retention and 100% coulombic efficiency when cycled 5000 times at a current density of 2 A g-1. HHPB electrodes reveal perfect EDLC behavior with an energy density of 20 W h kg-1 and power density of 2000 W kg-1 when used in a symmetric coin supercapacitor cell with 6 M KOH solution. These findings show the potential of fan palm bark as electrode materials with good stability and high-rate capability for supercapacitor application.