Tuning the photocatalytic activity of carbohydrate-derived humins via ball milling: Insights by experimental and chemometrics approach

This work demonstrates a facile ball milling modification approach for photocatalytic humins derived from H2SO4-dehydrated glucose-fructose syrup. The photocatalytic performance of the as-obtained materials was evaluated through degradation of Malachite Green (MG) as a model pollutant under visible light irradiation. Results clearly indicate that the prolonged milling (up to 120 min) enhances the photocatalytic activity of humins. Furthermore, the physicochemical characteristics of the milled humins were studied using a variety of imaging and spectroscopic techniques. The specific links between photocatalytic activity and the physicochemical features of the as-prepared samples were revealed via intelligent data analysis (chemometrics). The first 30 min of milling proved to be a very significant factor for advancing the photocatalytic ability of humins. Additionally, it was demonstrated that the textural characteristics, adsorption capacity and the presence of oxygen and sulfur functionalities in humins are mainly responsible for the successful ball milling preparation of an efficient bio-based photocatalyst.