Density Functional Theory-Guided Synthesis of Cu-N-TiO₂ for Overall Water Splitting by Breaking the Scaling Relationship

For solar-driven overall pure water splitting, a superior photocatalyst with reasonable atomic and electronic structure is needed to be suitable for both half-reactions, HER and OER. TiO2 has showcased remarkable catalytic efficiency in the field of HER but it still encounters obstacles in accomplishing proficient overall water splitting. Within this work, following a sequential screening based on element type, stability, electronic structure, and adsorption energy, we designed a TiO2-based catalyst screening workflow for solar-driven overall water splitting. This DFT-based workflow significantly reduced both the time and trial-and-error costs associated with a traditional experimental design. It precisely guided the synthesis of highly dispersed Cu-loaded/N-doped TiO2, which facilitated sacrificial-agent-free solar-driven overall water splitting, resulting in a solar to fuel efficiency of 0.2% and an H2 yield of 1027.7 μmol/h/g. Advanced DFT calculations revealed that the d–p orbital coupling between Cu and N broke the scaling relationship of the O-based intermediates. This work holds promise for extension to other catalytic reactions, offering valuable insights into catalyst design endeavors.