Jose C Conesa

Title : Enzyme-sulphide coupling for light-induced water splitting and CO2 reduction

Abstract:

Many sulphide semiconductors are photocatalytically active in significant ranges of the visible spectrum; our group has shown this, specifically, for In₂S₃ and SnS₂. Furthermore, by including V in these sulphides we have shown how their photocatalytic activities can be further extended to even the NIR range. Here we will show how coupling these sulphides with enzymes of hydrogenase or laccase types allow photoevolving H₂ or O₂.
First, we could show that combining In₂S₃ with a hydrogenase it was possible to generate photocatalytically H₂ in presence of a sacrificial agent. Then, we showed that combining In₂S₃ with a laccase it was possible to generate O₂ photoelectrochemically, this being the first time that such enzyme-sulphide combination allowed photoevolution of O₂. A similar photoelectochemical generation of O₂ could be shown by combining SnS₂ with a laccase enzyme.

Some of us carried out recently work which coupled an electrode with a formate dehydrogenase enzyme, including W as active species, so that it was possible to reduce electrocatalytically CO₂ to formate. Ongoing work will be shown here in which combining this latter enzyme with In₂S₃ nanoparticles allows to perform the same task photocatalytically.

Audience take away:

• How to use In₂S₃ and SnS₂ for HCOOH degradation and how to extend their range by doping with V
• How to couple these materials with enzymes to achieve photo-splitting of water
• How to drive as well, in preliminary work, the coupling of In₂S₃ with a formate dehydrogenase enzyme to achieve CO₂ reduction.

Biography:

J.C. Conesa entered the permanent staff of ICP in 1979. He was ICP Vicedirector, then ICP Director, being now ICP Ad Honorem Professor. He was first in Spain using SR techniques to study heterogeneous catalysis, and first in CSIC to use quantum calculations to understand them. He is expert in XPS and FTIR (including operando), EPR and UV-Vis-NIR. He analyzed CeO₂-supported metals and oxides, firstly for car depollution and later for H₂ production technologies. He keeps continued interest in photocatalysis and photoactive solids. He belongs to the Steering Committee of AMPEA, a Joint Programme of the European EERA devoted to sustainable energy. His more than 200 articles and book chapters have received more than 9900 citations.