Novel CoAl-LDH Nanosheets/BiPO4 nanorods composites for boosting photocatalytic degradation of phenol

Layered double hydroxide (LDH) with special layered structure has been proved to have excellent hole transport capacity and good stability. Herein, we report a high efficient composite photocatalyst of CoAl-LDH and BiPO4 prepared by hydrothermal and chemical adsorption (denoted as CoAl-LDH/BiPO4). Phenol can be entirely degraded by 1% CoAl-LDH/BiPO4 under 30 min ultraviolet (UV) light irradiation, and the degradation rate constants k are 3 times and 39 times higher than that of pure BiPO4 and CoAl-LDH, respectively. The enhanced photocatalytic activity can be attributed to effective holes transfer from BiPO4 to CoAl-LDH, which hinders the recombination of photogenerated charge carriers. In addition, the combination of BiPO4 and CoAl-LDH avoids the agglomeration of BiPO4 and improves the stability of BiPO4. Active species capture experiments indicate that superoxide radicals (·O2−) are the main active species responsible for the degradation of phenol. This work provides technical approaches and research ideas for solving the photogenerated charge carrier recombination problem of photocatalyst.