Publication date: 6th November 2020
The morphology of semiconductor photoelectrodes and metallic electrodes significantly affects the performance of (photo)electrochemical devices. Complex anisotropic morphologies are important for overcoming performance limiting bulk transport properties of semiconductor materials or enhancing the selectivity of CO2 reduction electrodes, but are often also an unintended outcome of the fabrication process. A better understanding of morphology-induced transport limitations of (photo)electrodes is needed to better understand the kinetics, degradation, and transport limitations, and to subsequently guide mesostructured design and performance optimization. We use direct pore-level simulations for the coupled transport characterization of mesostructured (photo)electrodes. I will introduce and discuss four short examples to show the importance of local heterogeneities and reaction environment on the performance and degradation: i) stochastic, particle-based lanthanum titanium oxynitride (LTON) photoanodes for water oxidation, ii) degradation in porous photoanodes made of compound semiconductors, iii) structured, inverse opal silver electrodes for CO2 reduction, and iv) CO2 reduction in gas diffusion electrodes.