Integrated photosystem II with MXene QDs/TiO2 inverse opal bioelectrode for mimic biophotovoltaic applications

Abstract

Photosystem II protein (PSII) plays an important role in hybrid artificial photosynthetic systems. The conversion efficiency of these hybrid bioelectrodes is influenced by several factors, including electron transfer, the loading capacity of PSII, and the absorption and conversion of solar energy. In this work, a bioinspired artificial photo-anode system was designed by integrating the PSII protein onto MXene quantum dots (QDs) modified photonic crystal electrodes. The TiO₂ inverse opal hybrid photonic crystal (TIO), which mimics the stacked structure of thylakoids, not only provides a larger surface area for protein loading but also enhances the conversion and absorption efficiency of solar energy. Consequently, the TIO/MXene QDs/PSII composite exhibits a higher photocurrent response and improved stability compared to TIO/PSII. Furthermore, the incorporation of MXene QDs facilitates the transfer of photogenerated electrons from the photosynthetic protein to the surface of the electrode. Additionally, the mediated electron transfer (MET) photocurrent response demonstrates outstanding intensity (18.95 μA·cm⁻²). This work provides a strategy for the construction of a hybrid solar energy conversion system based on a photosystem complex.