Facile construction of BiOBr/Bi2O2CO3 p-n heterojunction by precipitation conversion at ambient temperature for charge transfer and photocatalytic activity

In this study, an effective BiOBr/Bi2O2CO3 p-n heterojunction was established via a precipitation conversion method at ambient temperature. The light response of the hybrid was broadened for 16 nm compared with that of Bi2O2CO3. More importantly, the charge transfer in BiOBr/Bi2O2CO3 heterojunction was greatly promoted as evidenced by photocurrent, ESI and PL results. So the photocatalytic ability of BiOBr/Bi2O2CO3 was greatly improved towards degradation of organic pollutants. The sample of Br amount of 0.094 wt% showed the optimal photoactivity for RhB degradation, with a rate constant k of 14.8 times as much as that of Bi2O2CO3. The reason is ascribed to the established built-in electrical field and resulted band matching between BiOBr and Bi2O2CO3. Based on the results, the migration mechanism of photoinduced charges at the interface of the heterojunction was put forward. This work provides a useful perspective in design and fabrication of Bi(III)-based heterostructure with an enhanced photocatalytic activity.