Separate-free BiPO4/graphene aerogel with 3D network structure for efficient photocatalytic mineralization by adsorption enrichment and photocatalytic degradation

The energy-saving and thorough purification of industrial phenol, methylene blue (MB) and formaldehyde at room temperature causes great attention in the environment field. This manuscript aims to combine adsorptionenrichment and photocatalytic degradation pollutants using three-dimensional network structure BiPO4/graphene aerogel (GA), which is synthesized by one-step hydrothermal method. BiPO4 nanorods are distributed and anchored uniformly into the three-dimensional porous GA structure. In the static experiment, 70%-BiPO4/GA composites could degrade 50.67% phenol, which is greater than that of pure BiPO4 powder (31.99%). In the dynamic system, the degradation content of MB for 70%-BiPO4/GA composites is 96.23% and the degradation rate is 2.03 times of that of pure BiPO4 powder. Degradation content of gas phase formaldehyde is 26.4% in 2 h, which is 1.66 times than that of pure BiPO4, owing to the adsorption enrichment-synergistic photocatalytic degradation. High aspect ratio BiPO4 with thinnest graphene layers (about 4 layers) favors to lower the valence band maximum and enhances the oxidation ability. The mainly active species are superoxide and holes demonstrated by trapping experiment. Construction of BiPO4/GA composites solves the problem of GA adsorption saturation and poor photocatalytic activity of BiPO4. The results would serve as a theoretical basis and technical support for the pollutant purification field.

Automated summary

This study focuses on the energy-saving and thorough purification of industrial phenol, methylene blue (MB) and formaldehyde using a BiPO4/graphene aerogel composite. The results demonstrate that the composite material has excellent degradation efficiency both in static and dynamic experiments, showing promise for pollutant purification applications.