Solar fuels
Decarbonizing energy and mitigating the effects of carbon intensive processes represent critical steps towards a sustainable future. Catalytic processes will be heavily involved to reach these objectives, ideally using efficient and low-cost photocatalysts able to exploit visible light instead of precious metal-based catalysts. This work involves cross-disciplinary expertise in polymer chemistry, porous materials and electrocatalysis. Its distinguishing feature resides in the creation of new materials with large surface areas and finely adjusted electronic properties, to catalyse energy-related reactions such as water splitting (hydrogen evolution) or CO2 reduction.
Smart materials and composites
Advanced materials are key to technological developments in multiple fields such as health diagnostics, soft robotics, gas capture, industrial processes, renewable energies, or composite engineering. In particular, materials designed to respond or adapt to external stimuli represent an attractive class of compounds commercially demonstrated in windows that opacify at the flick of a switch, or in smart packaging that monitors the condition of packaged food. Although a large body of research in light-responsive materials exists, applications are often hampered by the very limited understanding of the correlation between nanoscale structure and resulting bulk properties. The research carried out in our lab addresses this crucial aspect. Light as a stimulus possesses unique properties that make it greatly appealing, including: 1) spatiotemporal control (where light goes, and when it goes there), 2) easy control over the amount (intensity) and the energy (wavelength) of light, and 3) the ability to pass through many solid or soft materials. Numerous materials undergoing reversible light-induced transformations have been investigated in recent years, and have generated attention owing to their many potential applications (high-density optical storage devices, molecular switches or wires, logic gates, optical or electronic devices, sensors). However, transformations in the solid state are hampered by large energy penalties arising from steric constraints. As a consequence, making useful devices based on such materials remains a challenge, and investigations of the impact of photoinduced transformations on the macroscopic properties of materials are almost completely non-existent. Here we investigate materials and composites with macroscopic properties (porosity, permeability, electrical conductivity and mechanical properties) that can be modified using light as an external stimulus. Understanding how transformations at the molecular level translate across scales truly sets this research apart, and will enable the bottom-up engineering of materials possessing emergent functionalities at the macro-scale.
Hydrogen storage
A modern view is that hydrogen ultimately derived from renewable sources, and used in applications such as fuel cell vehicles and the storage of intermittent renewable electricity, might be a competitive option in a sustainable energy future in the UK and internationally. As well as remaining an important industrial gas, for example in crude oil processing and ammonia synthesis, hydrogen in energy applications could lead to a reduction in use of limited fossil fuel reserves and, as a result, improved air quality, increased security and flexibility of energy supply, greater energy diversity and the support of existing and new industries. But most significantly, hydrogen could be important in the raft of emerging energy technologies leading to reduced emissions to the atmosphere of greenhouse gases, principally carbon dioxide from the combustion of fossil fuels, and hence to the mitigation of global climate emergency. Of all the technical challenges identified in delivering future energy technologies using hydrogen, fuel storage is considered to be the most difficult (even solid H2 is only about 10 % of the density of liquid water). While liquefied hydrogen (below 33 K) has been considered as an option, current state-of-the-art storage especially for future, commercial motor vehicles using hydrogen as a fuel, is based on pressurised gas to 700 bar at ambient temperature. High-pressure storage requires considerable materials and energy investment to achieve and maintain storage conditions, plus there are safety considerations and the lack of conformability options in tank design. The heavy and bulky systems that result are a particular problem in mobile applications. Alternative methods that may operate in less demanding conditions, and hence may lead to lighter, smaller, safer and more conformable systems, are based mainly on storing hydrogen either as H2 in nanoporous solids or as atoms or ions in chemical systems.
A widely-held view is that physical H2 storage in materials is attractive for energy applications as it potentially leads to to lower operating pressure and/or increased capacity. The aim of this research is to develop new adsorbents possessing a high surface area and finely-tuned pores such as to maximise their hydrogen storage capacity, or other desirable properties for gas storage or separation applications.