Structural properties of CuO/TiO2 nanorod in relation to their catalytic activity for simultaneous hydrogen production under solar light

•CuO/TiO2 nanorod exhibits an excellent photocatalytic activity.•A lower CuO content leads to a higher hydrogen generation rate.•H2 evolution rate from sacrificial methanol is higher than that from pure water.•XRD and XAS show Cu solid solution (CuxT1−xO2) in the lattice of TiO2 nanorods.

CuO was introduced into porous TiO2 nanorod through impregnation method. Before the impregnation step, TiO2 nanorod was hydrothermally synthesized from TiO2 powder in aqueous NaOH solution and followed by thermal treatment at 450 °C. The structures and properties of impregnated samples were characterized using various techniques, including XRD, BET, XAS, TEM, and UV-DRS. Their photocatalytic performance on simultaneous hydrogen production from pure water and aqueous methanol solution was also investigated under solar light. It was found that CuO/TiO2 nanorod possessed a high surface area, good photocatalytic property and excellent hydrogen generation activity. Incorporation of Cu ions into the lattice framework of anatase TiO2 nanorod enhanced the efficiency in visible region at 438–730 nm. Moreover, the XAS results showed that some Cu ions formed solid solution in the TiO2 nanorod (CuxT1−xO2). However, the excessive incorporation of Cu ions did not improve any ability of anatase TiO2 nanorod for production of hydrogen from pure water splitting. This could be due to the excessive CuO agglomeration at outside-pores which blocked the sensitization of TiO2 nanorod. Only 1% Cu/TiO2 nanorod was found to be a remarkable and an efficient photocatalyst for hydrogen production under solar light from both pure water and sacrificial methanol splitting. The highest rate of hydrogen production of 139.03 μmol h−1 gcatalyst−1 was found in sacrificial methanol which was 3.24% higher than in pure water.

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