Synthesis and photocatalytic activity of TiO_2 nanowires in the degradation of p-aminobenzoic acid: A comparative study with a commercial catalyst

摘要

The photocatalytic degradation of p-aminobenzoic acid was studied using TiO_2 nanowires as the catalyst synthesized through a hydrothermal procedure. The as-synthesized TiO_2 nanowires were fully characterized by SEM, TEM, XRD and Raman with a very high surface area of 512 m~2 g~(-1). The photocatalytic degradation of p-aminobenzoic acid was carried out under 180 min of constant radiation and the results were compared with P25 as commercial catalyst. Optimal experimental conditions were determined for TiO_2 nanowires with a catalyst dosage of 1.0 g L~(-1) under acidic conditions with a 20 μM p-aminobenzoic acid solution obtaining 95% of degradation. Under similar experimental conditions comparative studies were performed obtaining 98% of degradation when P25 is employed. In both systems, a pseudo first order reaction was found to provide the best correlations, with constant rates of 2.0 × 10~(-2) min~(-1) and 2.4 × 10~(-2) min~(-1) for TiO_2 nanowires and P25, respectively.