Factors affecting the catalytic activity of multi-walled carbon nanotube for ozonation of oxalic acid

► Initial pH values significantly influence the activity of MWCNT in ozonation. ► Lower activity of MWCNT is found at higher initial pH. ► A higher initial pH value is unfavorable to the adsorption of oxalic acid on MWCNT. ► Less adsorption of oxalic acid on MWCNT leads to the weakness of surface reactions.