Photothermal reduction of 4-nitrophenol to 4-aminophenol using silver/polydopamine catalysts

4-Nitrophenol (4-NP) is one of the most difficult treated water pollutants in industrial wastewater. Herein, the silver nanoparticle/polydopamine (Ag-PDA/PDMS) composite is successfully prepared by in situ reducing Ag catalyst on PDA surface. The Ag-PDA/PDMS catalytic layer possesses an excellent light-to-heat conversion ability and stability under light irradiation. The degradation rate of 4-NP to 4-aminophenol (4-AP) under light irradiation is significantly higher than that of non-irradiation, resulting from both the temperature rise in the catalytic layer, and hot electrons produced by Ag nanoparticles. The temperature rise caused by the photothermal conversion of light-irradiated catalytic layer dominates the performance improvement. The degradation rate of 4-NP reaches 95 % under light irradiation, demonstrating an efficient pathway to design the robust catalyst composites with high-performance photothermal conversion efficiency. • Ag-PDA catalytic layer exhibits an excellent photothermal conversion efficiency. • The conversion efficiency under light irradiation is significantly higher than that of non-irradiation. • The temperature increasing makes a major contribution to the catalytic performance.