Anion-exchange-mediated internal electric field for boosting photogenerated carrier separation and utilization

Heterojunctions modulated internal electric field (IEF) usually result in suboptimal efficiencies in carrier separation and utilization because of the narrow IEF distribution and long migration paths of photocarriers. In this work, we report distinctive bismuth oxyhydroxide compound nanorods (denoted as BOH NRs) featuring surface-exposed open channels and a simple chemical composition; by simply modifying the bulk anion layers to overcome the limitations of heterojunctions, the bulk IEF could be readily modulated. Benefiting from the unique crystal structure and the localization of valence electrons, the bulk IEF intensity increases with the atomic number of introduced halide anions. Therefore, A low exchange ratio (similar to 10%) with halide anions (I-, Br-, Cl-) gives rise to a prominent elevation in carrier separation efficiency and better photocatalytic performance for benzylamine coupling oxidation. Here, our work offers new insights into the design and optimization of semiconductor photocatalysts.

Automated summary

Modulating the internal electric field can enhance carrier separation and utilization efficiency; introducing halide anions can increase the bulk IEF intensity and improve photocatalytic performance, offering new insights into the design and optimization of semiconductor photocatalysts.