Ana has been awarded a Royal Society Grant (RGS\R1\201283) to develop 3D Printed Electrodes for Energy Conversion and Storage Technologies! Below the abstract of her project.
Sustainable energy production at an acceptable cost is key for its widespread application. At present, noble metals and metal oxides are the most widely used for electrocatalysis, but they suffer from low selectivity, poor durability and scarcity. The search for new materials and structures that use non noble metals is of paramount importance. 3D printing has received increasing attention in recent years, due to its flexibility and ability to design electrodes, which can incorporate electrocatalytic functional materials. This method enabled excellent control and tuneability of geometries and sizes at the micrometre scales while maintaining the characteristic advantages of their components. Another advantage of 3D printing technologies has to do with the ability to produce single parts consisting of multiple materials, even with printed gradients, which leads to highly tailored materials. However, the application of 3D printed electrodes in electrocatalysis is relatively new, only gaining momentum in the last years. Here I propose to use 3D printing to explore new electrode composites consisting of nanostructured graphene / transition metal electrocatalytic species for application in energy storage and conversion technologies. This research will lead to the development of a variety of electroactive composites, with different geometries and microstructures, and high electrocatalytic performance for batteries, fuel cells and water electrolyser systems. This research has the potential to truly transform the field of electrode design and expand the use of 3D printing techniques for the processing of new electrocatalytic architectures.
Monitoring Hydrogen Evolution Reaction Intermediates of Transition Metal Dichalcogenides via Operando Raman Spectroscopy
Adv. Funct. Mater. 2020, 2003035
A deeper understanding of the water‐splitting hydrogen evolution reaction (HER) mechanism during photocatalytic processes is crucial for the rational design of efficient photocatalysts. In particular, the HER mechanism promoted by multielement hybrid structures remains extremely challenging and elusive. Herein, an in situ photoelectrochemical/Raman measurement system is employed to monitor the HER mechanism of hybrid nanostructures under realistic working conditions via operando Raman spectra and linear‐sweep voltammetry curves. As a proof of concept, tunable composition transition metal dichalcogenides MoS2xSe2(1−x) nanosheets are used as a model photocatalyst to unveil the corresponding photocatalytic mechanism. The spectroscopic studies reveal that hydrogen atoms can be adsorbed to active sulfur and selenium atoms via intermediate species formed during the photocatalytic process. More importantly, the studies demonstrate that an exponential relationship exists between the number of reactive electrons and the Raman intensity of intermediate species, which can serve as a guideline to directly evaluate the HER performance in photocatalysts by comparing the Raman intensities of the intermediate species. As a simple, intuitive, and general analytical method, the designed operando Raman measurement approach provides a new tool for elucidating catalytic reaction mechanisms in a realistic and complex environment; and strategically improving H2 production performance of multielement photocatalysts.
Adv. Energy Mater. 2020, 2001575
Insufficient light absorption and low carrier separation/transfer efficiency constitute two key issues that hinder the development of efficient photocatalytic hydrogen production. Here, multishell ZnS/CoS2 bisulfide microspheres with gradient distribution of Zn based on the heat diffusion theory are designed. The Zn distribution can be adjusted by regulating the heating rate and manipulating the diffusion coefficients of the different elements conforming the multishell photocatalyst. Because of the unique structure, a gradient energy level is created from the core to the exterior of the multishell microspheres, which effectively facilitates the exciton separation and electron transfer. In addition, stronger light absorption and larger specific surface area have been achieved in the multishell ZnS/CoS2 photocatalysts. As a result, the multishell ZnS/CoS2 microspheres with gradient distribution of Zn exhibit a remarkable hydrogen production rate of 8001 µmol g−1 h−1, which is 3.5 times higher than that of the normal multishell ZnS/CoS2 particles with well‐distributed Zn and 11.3 times higher than that of the mixed nonshell ZnS and CoS2 particles. This work demonstrates for the first time that controlling the diffusion rate of the different elements in the semiconductor is an effective route to simultaneously regulate morphology and structure to design highly efficient photocatalysts.
Congratulations Carlos! Well done!
We had a great UK Redox Flow Battery Meeting yesterday, with lots of interesting talks and posters. Kathryn Toghill and the rest of the committee did an amazing job organising the event! I enjoyed listening to so much good research on flow batteries in the UK and abroad. Also, our Gengyu gave his first talk on Solar Flow Cells and got lots of interesting questions from the rest of participants. Well done Gengyu! Looking forward to the next meeting!
Pavel has been awarded a Best Presentation Award at the 2020 Russell Binions Research Symposium taken place online. Congratulations Pavel! Well done! 🙂
Qian has passed today her 30 month viva, which was done online. Well done Qian! Not much longer for your PhD thesis now!
Another Group Meeting held virtually. Nice to see everyone. I hope we can have these face-to-face soon!
Carbon Dots in Solar-to-Hydrogen Conversion
H. Luo, Q. Guo, P. Szilagyi, A. Belen Jorge, M. Titirici, Trends in Chemistry 2020.
Solar hydrogen production from catalytic water splitting is one of the many options available to help generate clean power and alleviate the threatening environmental concerns stemming from the use of fossil fuels. During the past decade, carbon dots (CDs) have shown great potential in their application for solar-driven hydrogen production owing to their exceptional photophysical and electrical properties derived from their sp2/sp3 hybridized core structure and rich surface functionality. In this review, we correlate the structural features of CDs with their optical and electronic properties and evaluate key properties for efficient solar energy-conversion applications with an emphasis on photocatalysis and photoelectrocatalysis, to shed some light on designing high performance CD-based photosystems.
Congratulations to Gengyu who has recently passes his 18 month viva! Well done!