Photocatalytic reduction for graphene oxide by PbTiO with high polarizability and its electrocatalytic application in pyrrole detection.

Quick recombination of photogenerated electrons and holes in photocatalytic process remains a huge challenge. And the routine efforts are concentrated on heterojunction, metal decoration and surface defect strategies. PbTiO as a typical perovskite ferroelectrics is with a strong built-inelectric field as self-junction caused by internal spontaneous polarization, facilitating the charge separation in the photocatalytic process. Here, under UV irradiation, L-shaped PbTiO with active (1 1 0) facet as a photocatalyst was applied to photo-reduce graphene oxide (GO), where a specific reduced graphene oxide (rGO)/PbTiO composite was synthesized in presence of isopropanol, a hole-trapping agent. According to the linear optical properties, the polarizability of PbTiO is calculated to 1.01 × 10 cm (2.68 times that of P25 (TiO)), inducing the photo-excited charge separation by PbTiO. Based on XPS characterization, a TiOC chemical bond is identified on the interface between rGO and PbTiO. The response peak current for an electrochemical sensor based on rGO/PbTiO was proportional to the concentration of pyrrole (6.6 × 10-3.1 × 10 M, R = 0.999), and an extremely low limit reaches to 2.38 × 10 M. In addition, polypyrrole during the pyrrole detection was realized by the multi-cycle oxidation process. And also, the electrochemical detection has been successfully applied for the pyrrole quantification in real samples.