In the process of photocatalytic degradation of plastics, the surface interaction between the plastic material and the photocatalyst results crucial. The present work focuses on using a specific TiO2 photocatalytic semiconductor whose hierarchical structure favours the interaction with low density polyethylene (LDPE), a key component in plastics. An exhaustive study of the nature of this interaction is conducted, analysing the influence of the atmosphere and radiation. The results obtained indicate that the observed interaction can be modulated by controlling the atmosphere, evolving into a degradation process whose mechanism also depends on the absence or the presence of light. This point is particularly relevant as it highlights the dual nature of TiO2 as both photocatalyst and catalyst

The authors acknowledge the Project TED2021-132779B-I00 funded by MICIU/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR.