g-C3N4@TiO2 photoanodes for high-efficiency QDSSCs: improved electron transfer and photochemical stability

Abstract

In QDSSCs, a photoanode is an important part of connecting the external circuit, providing support for the transmission of photogenerated carriers to the external circuit, and also providing an attachment site for QDs. In this study, we prepared a g-C₃N₄@TiO₂ composite for the photoanode by a two-step process. The results show that the use of g-C₃N₄@TiO₂ greatly increases the specific surface area of the material, effectively inhibits the “electron–hole” recombination, and optimizes the stability and catalytic performance of the photoanode. Among them, the cell equipped with the g-C₃N₄@TiO₂ photoanode has improved performance: J_sc = 26.5 mA cm⁻², PCE = 8.2%, V_oc = 0.62 eV, and FF = 0.50. Based on the research in this paper, it can be seen that the g-C₃N₄@TiO₂ composite applied to the photoanode can effectively improve the cell performance and provide a feasible idea for optimizing QDSSCs.