Bin(Tu)xCl3n: a novel sensitizer and its enhancement of BiOCl nanosheets' photocatalytic activity

Bismuth complexes, Bi-n(Tu)(x)Cl-3n, were found to be photosensitizers for the first time. BiOCl nanosheets with inner Bi-n(Tu)(x)Cl-3n were synthesized and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, UV-vis diffuse reflectance, Fourier transform infrared spectrometry, thermogravimetric analyses and photoluminescence. The as-synthesized BiOCl displayed high visible light (lambda >= 420 nm) photocatalytic activity which was 112 and 13 times higher than P25 and BiOCl without Bi-n(Tu)(x)Cl-3n, for degrading RhB, respectively. The investigation of the photocatalytic mechanism demonstrated that Bi-n(Tu)(x)Cl-3n sensitized the BiOCl and resulted in unusually high visible light photocatalytic activity. The superoxide radical was the main active species in the photodegradation process. Furthermore, the concentration of the superoxide radical was quantized by the molecular probe nitroblue tetrazolium.