NordCO2 PI Sascha Ott and postdoctoral fellow Maxime Laurans have prepared a new manuscript which has been accepted for publication. Congratulations to both!
Photoelectrochemical CO2 reduction is a promising approach for renewable fuel generation and to reduce greenhouse gas emissions. Owing to their synthetic tunability, molecular catalysts for the CO2 reduction reaction can give rise to high product selectivity. In this context, a RuII complex [Ru(HO-tpy)(6-mbpy)(NCCH3)]2+ (HOtpy = 4’-hydroxy-2,2’:6’,2’’-terpyridyne; 6-mbpy = 6-methyl-2,2’-bipyridine) was immobilized on a thin SiOx layer of a p-Si electrode that was decorated with a bromide-terminated molecular layer. Following characterisation of the assembled photocathodes by X-ray photoelectron spectroscopy and ellipsometry, PEC experiments demonstrate electron transfer from the p-Si to the Ru complex through the native oxide layer under illumination and a cathodic bias. A state-of-the-art photovoltage of 570 mV was determined by comparison with an analogous n-type Si assembly. While the photovoltage of the modified photocathode is promising for future photoelectrochemical CO2 reduction and the p-Si/SiOx junction seems to be unchanged during the PEC experiments, a fast desorption of the molecular Ru complex was observed. An in-depth investigation of the cathode degradation in comparison with reference materials highlights the role of the hydroxyl functionality of the Ru complex to ensure its grafting on the substrate. In contrast, an essential role of the bromide function on the Si substrate designed to engage with the hydroxyl group of the Ru complex in an SN2-type reaction could not be established.
You can find a list of publications by NordCO2 on our Publications page.