Superior photocatalytic activity of Cu doped NiWO4 for efficient degradation of benzene in air even under visible radiation

We effectively used Cu dopant to improve photocatalytic performance of NiWO4 to remove benzene in air. The obtained experimental result indicated that photocatalytic performance of the prepared Cu-NiWO4 materials were greater than that of the pure NiWO4. This was because Cu effectively acted as novel dopant, which not only affected valence band (VB) top and conduction band (CB) bottom of NiWO4 but also formed a medium energy level between CB and VB of the NiWO4 to decrease its energy band gap and electron-hole recombination rate. Hence, the photocatalyst produced large available charge amounts (electron and hole) initiating photocatalysis for degradation of gaseous benzene. The optimized Cu/Ni mole ratio for maximum improving photocatalytic performance of NiWO4 was 3%. The maximum benzene removal efficiency and its mineralization via visible light photocatalysis of the 3Cu-NiWO4 were 93.7 and 96.5%, respectively. The synthesized Cu-NiWO4 photocatalyst also presented great stability in benzene removal processes.