Exploring efficient TiO2 integration onto eucalyptus pulp-derived cellulose nanocrystals: a comparative investigation of synthesis methods and photocatalytic performance

Abstract

This study explored the facile synthesis of TiO₂ nanoparticles on cellulose nanocrystals (CNCs) derived from eucalyptus pulp through an in situ hydrolysis process conducted at low temperatures. A comparative analysis was performed to evaluate the properties of materials synthesized via three distinct methods: one-pot reaction, double reaction, and physical mixing. The one-pot reaction yielded CNCs with a notably high crystallinity index of 88.5%, whereas the double reaction resulted in decreased crystallinity from 84.9% to 60.8%. Notably, the anatase phase of TiO₂ formed on the CNC surface in both one-pot and double reactions without subsequent calcination. Additionally, these synthesis routes produced a hierarchical raspberry-like morphology in the TiO₂-CNC nanocomposites. The photocatalytic degradation of rhodamine B (RhB) was investigated using TiO₂-CNC catalysts under both UV and visible light irradiation, with assessment of dye removal efficiency and catalyst reusability over three consecutive cycles. TiO₂-CNC composites synthesized via one-pot and double reactions demonstrated comparable photocatalytic activity, achieving approximately 77–84% removal efficiency under both UV and visible light. In contrast, the mixing method exhibited high efficiency (95%) under UV light but yielded less than 60% dye removal under visible light after 150 min of irradiation. Furthermore, the one-pot reaction produced the highest catalyst recovery rate, exceeding 80%. These findings demonstrate that TiO₂-CNC nanocomposites prepared via the one-pot reaction offer significant advantages, including synthetic simplicity, reduced chemical consumption, and enhanced catalyst stability for sustainable photocatalytic applications.

Graphical abstract