Platinum-free photoelectrochromic devices working with copper-based electrolytes for ultrastable smart windows

Photoelectrochromic systems are devices designed for large-scale manufacturing of smart windows, capable of changing their transmittance according to external environmental conditions. This communication proposes the replacement of the two most critical photoelectrochemical device components studied so far, namely the counter electrode and the redox mediator. Regarding the first, graphene nanoplatelets are used to replace platinum, maintaining both its optical and electrocatalytic properties, and at the same time reducing the device cost. Secondly, a copper-based redox pair was chosen to solve the corrosion problems typically encountered with the iodine-based mediator. The combination of the above components led to devices with high performance (coloration speeds in the order of seconds, with a maximum contrast ratio of 10.4 : 1), as well as the achievement of a long-term stability record (over 400 days) for these photoelectrochromic systems.

Automated summary

A new photoelectrochromic system has been proposed in this study, with improved device performance achieved by replacing key components, including using graphene nanoplatelets to replace platinum for the counter electrode, and choosing a copper-based redox pair to replace the iodine-based mediator. Compared to traditional designs, this system exhibits higher performance and long-term stability.