Improving the catalytic activity of bentonite-based bismuth ferrites composite via mechanical activation for photo-Fenton process

A bentonite-based bismuth ferrites (BiFe/Bent) composite has been fabricated by a sol-gel process in our previous study. To further improve the catalytic activity of BiFe/Bent in photo-Fenton reaction, the activation of BiFe/Bent by mechanical activation process was studied in this work. The effects of on the catalytic activity and physicochemical change of activated composite (A-BiFe/Bent) were investigated. The optimum conditions for activation of BiFe/Bent were as follows: filling ratio of grinding medium 30%, Phi(10) balls as grinding medium, rotation speed of planet carrier 600 rpm, milling time 30 min, and mass of composite activated 5 g L-1 (per unit volume of milling chamber). After mechanical activation, besides the improvement from the activity components of BiFeO3 and Bi2Fe4O9, the changes in the microstructure of activated composite, including enhanced specific surface area, improved pore structure, high defectiveness in structure, and small size of activity components, were the main reasons for the improved catalytic activity of A-BiFe/Bent. Compared with that of BiFe/Bent, the catalytic activity of A-BiFe/Bent was improved about by 1-fold, and the A-BiFe/Bent exhibited good stability and low Fe leaching. It was advisable to implement mechanical activation as a strategy to promote the catalytic efficiency of BiFe/Bent.

Automated summary

The study focused on activating BiFe/Bent composite through mechanical activation, leading to improved catalytic activity and changes in physicochemical properties. The main reasons for enhanced catalytic activity of the activated composite were attributed to changes in microstructure. Mechanical activation was identified as a strategy to promote catalytic efficiency of the composite material.