Preparation and photocatalytic degradation kinetics of La–BiOCl/LDHs composites

An La–BiOCl/layered double hydroxide (LDH) composite photocatalyst was prepared with a hydrothermal method by using Bi(NO3)3·5H2O and La(NO3)3·6H2O as precursors and LDHs as a support. The photocatalytic performance of the materials was evaluated by taking tetracycline (TC) hydrochloride as the target pollutant. The results show that La3+ enters the BiOCl lattice and replaces Bi3+ to form an La–O–Bi bond after loading La–BiOCl onto the hydrotalcite. The surface area of the material is 42.5733 ​m2/g, the average particle size is 13.5371 ​nm, the optical absorption threshold is increased from 374.6 ​nm to 472.9 ​nm, and the bandgap width is 2.62 ​eV. Under irradiation by a visible light source, the rate of removal of TC hydrochloride is increased from 49.6% to 79.8% within 2 ​h. The photocatalytic degradation process is governed by a first-order kinetic model. [Display omitted] •La-BiOCl /LDHs photocatalyst was prepared by hydrothermal method, and its photocatalytic effect on TC was further evaluated.•The width of the band gap is reduced from 3.31 ​eV to 2.62 ​eV.•Under the optimal conditions, the removal rate of TC is 79.8%, and the reuse performance is good.