Reuse and Valorization of Vanadium and Tungsten from Waste V2O5-WO3/TiO2 SCR Catalyst

The catalytic removal of NOx technologies must pay attention to waste selective catalytic reduction (SCR) catalysts, which are the traditional commercial V2O5-WO3/TiO2 catalysts. Our work focuses on the progress in green reclamation and green chemistry for dealing with the spent SCR catalysts with sustainability perspectives. The problem outlined deals largely with the study of a feasible preparation way for visible-light-sensitive BiVO4/Bi2WO6 heterojunction photocatalyst, which was synthesized via a hydrothermal process through waste SCR catalysts. In this paper, the simulated waste SCR catalyst dissolved by sodium hydroxide (NaOH) solution was proposed. V2O5 and WO3 were dissolved heavily while TiO2 was rarely dissolved by sodium hydroxide. Afterword, the dissolved vanadium and tungsten in leaching solution were used to produce BiVO4/Bi2WO6 heterojunction through a hydrothermal process at 160 A degrees C, which can be used as photocatalyst. The photocatalytic performance of the BiVO4/Bi2WO6 sample was evaluated by degradation of methylene blue in aqueous solution under visible light irradiation, which attributed to the improved separation efficiency of photogenerated hole-electron pairs generated by the heterojunction between Bi2WO6 and BiVO4.