Combining data-driven and quantum chemical calculations to optimize the spectral matching and activity regulation of organic photocatalysts

In response to the problems of insufficient visible light response (spectral mismatch) and high carrier recombination rate (limited activity) of organic photocatalysts, this study constructed a data set based on the Material Project database, covering the multi-dimensional feature information of 12, 000 organic photocatalyst molecules. Subsequently, the XGBoost algorithm is used to mine and analyze this dataset to identify candidate materials with suitable band gaps (1.5-3.0 eV). After screening out suitable candidate materials, quantum chemical calculation technology is further introduced to optimize the spectral response and catalytic activity of these materials. Specifically, the B3LYP/6-311G(d,p) basis set is used to optimize the ground state of density functional theory (DFT), and then the time-dependent density functional theory (TDDFT) is used to simulate the π→π* and n→π* electronic transition processes, and the structure-activity relationship between the spectral response range and the oscillator strength is quantitatively analyzed. To reduce the carrier recombination rate and improve the activity of the catalyst, a 3D graph convolutional network (3D-GCN) model based on the attention mechanism is also developed. Through atomic polarization tensor (APT) and Fukui function analysis, the complex relationship between substituent effect, conjugation length, and hole-electron separation efficiency is explored, and a quantitative mapping model is constructed based on this. After optimization, the average oscillator strength is 0.721, the absorption edge redshift error is reduced, and the spectral response is matched with the solar spectrum with high precision. At the same time, the carrier recombination rate is also greatly reduced. This study provides important theoretical support and practical guidance for promoting the application of photocatalytic technology in the fields of environmental protection and clean energy.