CdSxSe1−x nanowhiskers sensitized Nitrogen-doped TiO2: 3D-branched photoelectrode and its photoelectrochemical properties

•3D branched nanostructure photoelectrode was fabricated.•PEC cell was assembled according to the three-key-aspects for efficient PEC devices.•Synergistic effect of CdSxSe1−x and N dopant are attributed to the enhanced PEC performance of the assembled cells.

Light absorption, appropriate interfacial redox reaction, and photogenerated charge carriers separation are the three-key-aspect of efficient photoelectrochemical (PEC) devices. 3D-branched nanostructure photoelectrode was prepared by growing CdSxSe1−x nanowhiskers around the head of Nitrogen-doped TiO2 nanorods (NRs). PEC cells were assembled according to the aforesaid three-key-aspect. Synergistic effect of CdSxSe1−x sensitization and substituted N dopants was confirmed on the improved photocurrent properties of CdSxSe1−x/N-TiO2 photoelectrode. Meanwhile, the inferred type II band edge alignment in it facilitated the separation of photogenerated charge carriers. Moreover, 3D hierarchical nanostructure of CdSxSe1−x/N-TiO2 provided higher specific surface area and the result of more active sites for PEC reaction. Our work would be of some benefits to design and manufacture high performance photoelectrodes and assemble efficient PEC cells for solar energy conversion.

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