Highly efficient TiO2 nanotube photocatalyst for simultaneous hydrogen production and copper removal from water

1-D mesoporous TiO2 nanotube (TNT) with large BET surface area was successfully synthesized by a hydrothermal-calcination process, and employed for simultaneous photocatalytic H2 production and Cu2+ removal from water. Cu2+, across a wide concentration range of 8–800 ppm, was removed rapidly from water under irradiation. The removed Cu2+ then combined with TNT to produce efficient Cu incorporated TNT (Cu-TNT) photocatalyst for H2 production. Average H2 generation rate recorded across a 4 h reaction was between 15.7 and 40.2 mmol h−1 g−1catalyst, depending on initial Cu2+/Ti ratio in solution, which was optimized at 10 atom%. In addition, reduction process of Cu2+ was also a critical factor in governing H2 evolution. In comparison with P25, its large surface area and 1-D tubular structure endowed TNT with higher photocatalytic activity in both Cu2+ removal and H2 production.

► Simultaneous H2 production and Cu2+ removal were achieved over TiO2 nanotube.
► TiO2 nanotube possessed greater photocatalytic activity than P25.
► Average H2 evolution rate depended on initial Cu2+/Ti ratio in solution.
► H2 evolution during photocatalytic reaction was governed by Cu2+ reduction process.