2026-10-12T18:56:07Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34003136 2026-09-26T14:17:31Z category_146 category_14 category_21 category_873 category_734 category_135 portal_63 item_type_2 month_year_09_2026

Direct Observation of Tantalum Nitride Photoelectrode Degradation by Environmental Transmission Electron Microscopy Annett Th⌀gersen (25114580) Shima Kadkhodazadeh (1367082) Michael Stanislaus Seifner (25114583) Monia Runge Nielsen (21020393) Ingvild J. T. Jensen (10708882) Martin Fleissner Sunding (2132467) Ingeborg-Helene Svenum (1452526) Mathieu Grandcolas (16864741) Øystein Dahl (16864735) Murat Nulati Yesibolati (11682503) Thomas Willum Hansen (11858071) Athanasios Chatzitakis (7256564) Space Science Molecular Biology Biotechnology Chemical Sciences not elsewhere classified Biological Sciences not elsewhere classified Computational Biology solar fuel production providing concrete targets photocorrosion often leads macroscopic device degradation insulating amorphous tao customized optical add commercially available chip relevant operating conditions rapid performance degradation probing dynamic processes amorphous surface layers functional energy materials 5 </ sub 3 </ sub x </ situ </ surface interphases processes lead performance loss work establishes widely recognized time atomic structural evolution stabilization strategies scale imaging results demonstrate propagating amorphization photocurrent stability operating photoanodes electrical biasing directly capture directly associated direct observation critical challenge combined stimuli broader potential atomic level Stability under realistic operating conditions remains a critical challenge for photoelectrochemical (PEC) materials in solar fuel production, where photocorrosion often leads to rapid performance degradation. In particular, the formation of insulating amorphous TaO_<i>x</i>/Ta(O,N)_<i>x</i> surface interphases is widely recognized as a key factor limiting charge transfer and photocurrent stability in Ta₃N₅ photoanodes. Addressing this challenge requires experimental approaches capable of probing dynamic processes at the atomic level under relevant operating conditions. Here, we develop an <i>in situ</i> environmental transmission electron microscopy (ETEM) platform that integrates simultaneous light illumination, electrical biasing, and controlled water vapor exposure within a commercially available chip, supplemented with a customized optical add-on. This multistimulus configuration enables real-time atomic-scale imaging of PEC materials under conditions closely resembling operation. Applying this platform to Ta₃N₅, we directly capture its structural evolution under combined stimuli and reveal a previously unresolved degradation pathway involving nanocrystal detachment, migration, and inward-propagating amorphization. These processes lead to the growth of amorphous surface layers that are directly associated with performance loss in operating photoanodes. More broadly, this work establishes a mechanistic framework linking nanoscale structural transformations to macroscopic device degradation, providing concrete targets for stabilization strategies in Ta₃N₅ and related metastable PEC materials. In addition, the results demonstrate the broader potential of multistimulus ETEM for investigating complex degradation phenomena in functional energy materials. 2026-09-26T00:00:00Z Dataset Media 10.1021/acsnanoscienceau.6c00123.s001 https://figshare.com/articles/media/Direct_Observation_of_Tantalum_Nitride_Photoelectrode_Degradation_by_Environmental_Transmission_Electron_Microscopy/34003136 CC BY-NC 4.0