Design of two kinds of branched TiO2 nano array photoanodes and their comparison of photoelectrochemical performances

- Rutile TiO2 nanorods grown rutile(BTNRs) and anatase (ATNRs) branches are designed.
- Photoelectrochemical (PEC) performances of BTNRs and ATNRs are comparably evaluated.
- ATNRs show a higher PEC activity than BTNRs due to a lower intrinsic resistance.
- Heterophase branched structure of anatase and rutile is proven to be more effective.

Two kinds of branched TiO2 nanorods arrays (TNRs), i.e. rutile nanorod covered with rutile branches (BTNRs) and rutile nanorod covered with anatase branches (ATNRs), were synthesized on FTO films as photoanodes. Photoelectrochemical (PEC) performances of the both photoanodes were comparably evaluated. The PEC hydrogen production rate of ATNRs photoanode is 4.2 and 2.7 times those of the TNRs and BTNRs photoanodes, respectively. The ATNRs showed a highly PEC response because of a lower intrinsic resistance and a heterophase structure between rutile nanorod and anatase branches. The study explicitly ascertains a kind of more effective structure for photoelectrical materials and gives new insight into intrinsic resistance based on PEC analyses.

174Rutile TiO2 nanorods grown anatase branches show a higher photoelectrochemical activity than grown rutile ones because of a lower intrinsic resistance and a heterophase structure between anatase branches and rutile trunks.