This study concerns SnFe2O4 spinel (SFO) photocatalytic CO2 reduction properties both alone and in combination with other materials, its synthesis compared to methods presented in literature, and how the products are influenced by pH in wet methods syntheses. Many well-known photocatalytic materials exhibit too wide band gaps limiting the absorption spectra to ultraviolet range which forms only a small fraction of solar radiation, or have too weak reductive power due to not sufficiently high level of the conduction band. These shortcomings can be alleviated by combining two materials, one being oxidative photocatalyst and one reductive photocatalyst forming the so called Z-Scheme. In such a system at the expense of absorption of two photons of lower energy (visible range which is the main component of solar spectrum) an electron, at high enough potentials to reduce CO2, can be obtained along with a hole which can oxidize for example water. Such a system could be realized with for example SFO which is a p-type semiconductor, and is reported to have a high energy conduction band, with an n-type material. Here the analysis and deliberations of earlier mentioned systems will be presented.
Acknowledgements: The authors would like to acknowledge the financial support of this work from the National Centre for Science through grant no. NCN 2018/30/Q/ST5/00776 (SHENG-1).
 Y. Jia Et al., Chem. Eng. Jour., 2020, 383, 123172, https://doi.org/10.1016/j.cej.2019.123172