Design of TiO₂-Based Materials for Photocatalytic Biomass Valorization

Recently, reliance on nonrenewable fossil fuels has raised sustainability concerns, prompting interest in lignocellulosic biomass as a renewable resource. Furfural stands out as a key compound, with its selective reduction to furfuryl alcohol being of industrial significance. Traditional hydrogenation methods are harsh. Photocatalysis, utilizing semiconductor materials like TiO₂, works under mild conditions by harnessing light as the energy source. These materials, however, face efficiency issues due to rapid charge recombination that reduces their efficiency. This study explored the effect of calcination temperature on TiO₂ catalysts synthesized via solution combustion synthesis (SCS), using varying temperatures from 400 to 550 °C. Characterization via XRD, BET, ATR-FTIR, TGA, and DRS confirmed the anatase phase, with increased crystallite size and decreased surface area at higher temperatures due to sintering. Optimal catalytic performance for furfural photoreduction to furfuryl alcohol was observed at 470 °C, balancing carbon removal and sintering effects. The optimised catalyst was further tested to evaluate how some key parameters, such as catalyst loading, substrate concentration, and irradiation time, affect performance. Comparison with a commercial benchmark clearly demonstrated the superior performance of the optimised catalyst, showing up to 60% higher conversion under standard experimental conditions. Reusability tests demonstrated the catalyst's stability across multiple cycles, showcasing the potential of SCS-derived TiO₂ in advancing photocatalytic technologies as viable alternatives to conventional methods.