Comparative study of Ti-alkaline biochar and Ti-acidic biochar photo catalysts for degradation of methyl orange,

Abstract The biochar was produced from wood waste via pyrolysis. The biochar with pH 9.7 was comprised of titanium species named Ti-WB9. After acidification, the acidic biochar with pH 3.66 was also comprised of titanium species named Ti-WB3. Using XRD, the particle sizes of anatase TiO2 were 7 and 8 nm in Ti-WB9 and Ti-WB3, respectively; these were then synthesized via the solvothermal method at low temperature. The degradation efficiencies of methyl orange were 93.5 and 95.1% in 120 min with Ti-WB9 and Ti-WB3, respectively. During degradation, the by-products were barely observed in the solution when Ti-WB3 was used as a photocatalyst under UV light. However, the by-products exited in another solution that used Ti-WB9 as a photocatalyst for degradation according to the results of UV-Vis and FTIR. Via XPS, the formation of C-Ti in Ti-WB3 played an important role in the enhanced and complete degradation of methyl orange without by-products.