New article published: In situ X-ray absorption spectroscopy to study redox dynamics in Ni and Cu co-catalysts on porous TiO2 photocatalyst films during H2 evolution

Dr. Marco Altomare [PCS], Marco Pinna [University of Insubria], and MemetTursun Abudukade [PCS] published a paper in Applied Catalysis A: General titled In situ X-ray absorption spectroscopy to study redox dynamics in Ni and Cu co-catalysts on porous TiO2 photocatalyst films during H2 evolution

This article looks a how in-situ X-ray Absorption Spectroscopy (XAS) at ID26 of the ESRF is used to investigate how Ni, Cu, and bimetallic NiCu co-catalysts behave during photocatalytic hydrogen evolution on porous TiO₂ films.

While NiCu systems are often reported to outperform their monometallic counterparts, the origin of this synergy has remained debated. By monitoring the oxidation state of the co-catalysts under operating conditions, we observed that the two metals play distinct and complementary roles:

- Cu acts as an efficient electron sink, promoting hydrogen evolution.
- Ni behaves as a dynamic hole buffer, undergoing reversible oxidation processes that help improve charge separation and suppress deactivation pathways.

These findings highlight the importance of studying photocatalysts while they are working, as ex situ characterization alone may miss key dynamic processes occurring under reaction conditions.

You can read the article here: https://www.sciencedirect.com/science/article/pii/S0926860X26002991?via%3Dihub