There are also challenges facing future computational development of 2D conjugated polymers for photocatalysis. (1) Although HSE06 is currently a compromised option to reproduce the band structures of 2D polymers, a more accurate and less expensive theory need to be developed to well describe the electronic and optical properties. The kinetics of solar-driven HER and OER on 2D polymers need to be studied in depth and the pH conditions should be fully considered to obtain a comprehensive understanding of the real water splitting processes. (3) An integrated and comprehensive material library of 2D polymers and their building units need to be complemented to provide a data base for the future design and screen of 2DCPs for photocatalysis and photovoltaics, which requires the combination of artificial intelligence technologies (e.g. high throughput computation and machine learning).