Photocatalysis Enhanced by 3D Multi-Scale Structured Supraparticles (SPs)

Photocatalysis Enhanced by 3D Multi-Scale Structured Supraparticles (SPs)
Joint Doctorate
1st supervisor and 1st promotor: Prof. Alfons van Blaaderen (UU)
2nd supervisor and 2nd promotor: Prof. Rob Lammertink (UT)
Affiliation: Utrecht University and University of Twente
Research theme: Smart Biomass Conversion

Structuring heterogeneous catalysts at multiple length scales to enhance performance at multiple levels is at the heart of the MCEC consortium. Here we want to make several micrometer sized particles build up from two kinds of smaller nano-particles, one being composed of titanium dioxide (spheres and rods) and the other being silica or a noble metal particle (e.g Pt). By having these small nanoparticles self-assemble inside drying droplets, micron-sized ‘supraparticles’ will be made in which light can by multiple scattering form so-called Mie Whispering Gallery resonances.

Recently we have shown that this enhancement can lead to supraparticles that support lasing! With these resonances light can be made to interact stronger with the catalyst within the supraparticle, thus enhancing photocatalysis (e.g. water splitting). Moreover, by structuring of the two nanoparticle components within the SP on catalyst length scale (e.g. patches of catalytic material next to non-catalytic surface area) we want to improve the catalysis by creating local convection currents to enhance transport.

The proof of concept of this enhanced convective transport on structures titania catalysts has been demonstrated in 2D and will be extended into 3D catalytic assemblies guided by calculations and simulations.

Keywords:

• Self-assembly
• Photo-catalysis
• Enhanced convection
• Colloids
• Confocal microscopy