Non-centrosymmetric Hollow BiOCl Nanocaps with Tailored Openings for the Photocatalytic Degradation of Rhodamine B

Micelles of surfactants have been employed as a powerful tool for the synthesis of hollow nanostructures. Nonetheless, it is still challenging to use micelles to direct the growth of hollow nanostructures with open interiors, especially for crystalline materials. Herein, we report a versatile method to precisely synthesize non-centrosymmetric hollow BiOCl nanocaps with open interiors for the first time. The growth mechanism of the hollow BiOCl nanocaps is elucidated, and the openings of BiOCl nanocaps can be precisely controlled by fine tuning their growth conditions. The non-centrosymmetric BiOCl nanocaps yield a pseudo -first-order degradation kinetic rate constant of up to 0.1217 min^-1 in the photodegradation of rhodamine-B, 7.8 times higher than that of common BiOCl nanoplates. This suggests that BiOCl nanocaps show excellent photocatalytic performance to degrade colored rhodamine B. Furthermore, the BiOCl nanocaps can be also extended in the photodegradation of colorless contaminants in industrial wastewater. More importantly, the micelle-directed growth strategy can be generalized to synthesize noncentrosymmetric BiOCl_0.5Br_0.5 and BiOBr hollow nanocaps. This synthetic strategy heralds a paradigm for designing noncentrosymmetric hollow nanostructures with micelles and may open up an avenue for unique hollow nanomaterials with tailorable structures and properties.