Fabrication of Ag/TiO2 membrane on Ti substrate with integral structure for catalytic reduction of 4-nitrophenol

In this work, Ag/TiO2 monolithic membrane catalyst was successfully fabricated on alpha-titanium plate by using a facile two-step method. Firstly, a layer of anatase TiO2 film with nanosheet morphology was formed by the hydrothermal reaction in combination with calcination. After photo-deposition in AgNO3 solution under the ultraviolet irradiation, Ag nanoparticles in metallic state were then deposited on the surface of the as-prepared Ti-based TiO2 film. The catalytic performance of the Ag/TiO2 membrane in the presence of NaBH4 was evaluated by taking p-nitrophenol (4-NP) as a pollutant model. The results indicated that the Ag/TiO2 as a monolithic membrane catalyst exhibited excellent catalytic ability and high stability towards 4-NP degradation. During six consecutive recycling runs, the degradation rates of 4-NP were maintained above 73%, with slight difference. This study shows that the monolithic membrane catalyst Ag/TiO2 is a promising material for the degradation of 4-NP owe to its high activity and easy recovery.