A novel computational screening study of single transition metal (TM), TM-doped, and dual TMs-doped on CdS (110) surfaces via DFT calculations is presented, focusing on their stability and catalytic activity, searching for efficient photocatalysts for hydrogen production. Criteria based on key performance descriptors allowed to fine-tune the selection. Results indicate that TM dopants can reduce the energy band gap and enhance impurity d-states. Pt, Rh, and Pd were found to be the best dopants in TM-doped CdS, since their $$\left| {\Delta G_H} \right|$$
Δ
G
H
is 80% smaller compared to the pristine CdS surface. Moreover, TM1-TM2-co-doped CdS catalysts show better performance for the hydrogen evolution reaction (HER) due to synergistic effects of the two TMs, where Co-Pt, Pd-Pt and Co-Rh co-doping CdS significantly reduced $$\left| {\Delta G_H} \right|$$
Δ
G
H
to less than 0.1 eV. Results point out four promising novel co-catalysts (i.e., Co, Co-Pt, Co-Rh, Rh-Ag) with very good performance in HER, to be further explored in experimental studies.