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Nymphaea-like BiOCl with oxygen vacancies (OVs) was successfully prepared by adjusting the pH of the precursor and using aspartic acid as a surfactant. The as-fabricated samples were investigated by the XRD, SEM, TEM, BET, DRS, PL and SPV techniques. The results reveal that the morphology of the as-prepared samples was self-assembled by thinner nanosheets. Moreover, the sample prepared at pH = 4 can remove 80% of tetracycline hydrochloride (TC, 10 mg L−1) in 1 h. This outstanding photocatalytic performance is attributed to the shorter migration distance of photo-induced carriers due to the thinner nanosheets and the high separation efficiency of photo-generated electron–hole pairs induced by OVs. Furthermore, the dominant free radicals in the present system were identified by trapping experiments and ESR methods. This work provides a new ideal to augment the photocatalytic activity of BiOCl through morphology control and defect engineering. [ABSTRACT FROM AUTHOR]

A feathery-shaped form of BiOCl (BOC-M) with a high concentration of oxygen vacancies was successfully synthesized using the ultrasound method at room temperature with maltitol as a surfactant. BOC-M was found to exhibit excellent visible-light photocatalytic activities for the degradations of the antibiotic tetracycline hydrochloride (TC-HCl) and rhodamine B (RhB), whose reaction rate was found to be approximately 3 times higher than that using bulk BiOCl (BOC). The enhanced visible photocatalytic performance of BOC-M was ascribed to its high concentration of oxygen vacancies, large specific surface area and strong hydrophilicity. Moreover, the photocatalytic reaction mechanism was further revealed by performing radical- and hole-trapping experiments and electron spin resonance spectroscopy (ESR). The results suggested that ṖO2− was the main active species during the degradation process. This work provided a facile and scalable method to synthesize maltitol-assisted Bi-based photocatalysts and shed light on the highly efficient catalysis offered by BiOCl resulting from the oxygen vacancies produced by the new synthetic route we developed. [ABSTRACT FROM AUTHOR]