Facet engineering for improved carrier separation and transport in CuFeO2 photocathodes

The development of CuFeO 2 photocathodes is hindered by challenges associated with low carrier separation and transport efficiency. In recent years, facet engineering has emerged as a promising solution to overcome these limitations. In this study, CuFeO 2 samples with varying crystal facets and morphology were successfully synthesized through precise control of hydrothermal reaction time, ultrasonic time, and the introduction of a surfactant . Among the synthesized samples, the nanosheet CuFeO 2 exhibited an impressive 83.36% exposure ratio of (001) facets and demonstrated the highest photocurrent density of 5.3 μA/cm 2 when compared to both cubic CuFeO 2 with (012) facets and octahedral CuFeO 2 with (001) facets. The exceptional photoelectrochemical performance of the nanosheet CuFeO 2 can be attributed to the polar nature of the (001) crystal plane, which induces a surface polarization effect. This effect significantly enhances the separation efficiency of photoexcited electron-hole pairs. Additionally, the nanoscale dimensions of the CuFeO 2 nanosheets minimize carrier diffusion distances, leading to improved carrier transport efficiency. Overall, this study highlights the feasibility and immense potential of employing facet engineering as a strategic approach for enhancing the photoelectrochemical performance of CuFeO 2 photocathodes. The successful synthesis of CuFeO 2 samples with optimized crystal facets opens up new avenues for advancing the development of efficient photoelectrochemical devices.