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It is demonstrated that the incorporation of graphene materials into oxide-based photoanodes can greatly increase the photoelectrochemical devices' performances. In this work, reduced graphene oxide (rGO) has been incorporated into P25-TiO 2 nanoparticle (NP) based photoanodes for fiber-shaped dye-sensitized solar cells (FDSSCs). Results showed that the rGO nanosheets have been uniformly dispersed within P25 nanoparticle layers, and, as expected, the incorporation of rGO increased the FDSSCs' short current density from 8.344 to 12.935 mA cm −2 , open circuit voltage from 0.775 to 0.798 V, resulting into their power conversion efficiency (PCE) from 3.940% to 5.364%. This large increasement in PCE could be due to two aspects, i.e. the improved electron transport properties via rGO and the enhanced separation of photogenerated hole-electron pairs via rGO-TiO 2 heterojunction. Furthermore, the incorporation of rGO can also make the FDSSCs have good mechanical properties, which is very crucial for their future applications in smart wearable electronics. In addition, based on our analysis, a possible rGO/multi-NP coupling enhancement mechanism was proposed.

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Ordered array structures will greatly reduce the stress formation in wearable electric devices during dynamic bending operation. In this work, highly flexible TiN-based fiber counter electrodes (FCEs) were designed via a post-ammonization treatment on the hydrothermally grown TiO2 nanowire arrays. Results show that the obtained TiN nanorod arrays (NRAs) are well aligned with a diameter of 200–320 nm and a length of several hundred nanometers to ∼1 μm. Moreover, fiber-shaped dye-sensitized solar cells assembled using TiN FCEs showed the maximum photoelectric conversion efficiency (PCE) of 5.69%, which is 16.3% higher than that of the ones based on Pt FCEs. Analysis indicated that this enhancement in PCE could be mainly due to the better electrochemical catalytic activity of TiN NRAs. Furthermore, the optimizations of the nanoscale morphologies of TiN NRAs suggest that both small diameters and large lengths can benefit the PCE and the dynamic bending stability, while the diameters show a major influence on them. The optimal FCEs show an ultralow decay rate of 0.017‰ per bending cycle.