Synthesis, characterization, photocatalytic activity of visible-light-responsive photocatalysts BiOxCly/BiOmBrn by controlled hydrothermal method

• This is the first report that a series of BiOxCly/BiOmBrn heterojunctions.
• The compositions of BiOxCly/BiOmBrn could be controlled by adjusting growth parameters.
• DR spectra show the BiOxCly/BiOmBrn to be indirect semiconductors with an bandgap of 2.87–2.15 eV.
• The photocatalytic efficiencies were evaluated with the CV dye.
• Intermediates were separated using HPLC-MS to propose the possible mechanism.

Bismuth oxyhalide and its composite belong to a new family of visible light driven photocatalysts and attract more and more attention because of their interesting structures dependent on the photocatalytic performance arisen from their layered structures interleaved with [Bi2O2] slabs and double halogen atoms slabs. An effective and simple strategy to improve the photocatalytic activity of a photocatalyst is the construction of a heterostructure, as the heterojunction has great potential in tuning the desired electronic properties of the composite photocatalysts and efficiently separating the photogenerated electron–hole pairs. This is the first report that a series of BiOxCly/BiOmBrn heterojunctions are prepared using controlled hydrothermal methods. The compositions and morphologies of BiOxCly/BiOmBrn could be controlled by adjusting some growth parameters, including reaction pH, time, and temperature. The products are characterized by XRD, SEM-EDS, HR-TEM, DR-UV, BET, CL, and HR-XPS.

The increased photocatalytic activities of BiOxCly/BiOmBrn could be attributed to the formation of the heterojunction between BiOxCly and BiOmBrn, which effectively suppresses the recombination of photoinduced electron–hole pairs. Both the photocatalytic process and the photosensitized process would work concurrently. OH and O2− are two main active species in the whole process.Figure optionsDownload high-quality image (88 K)Download as PowerPoint slide