Enhancing the hydrogen evolution reaction by group IIIA-VIA elements doping in SnS2 basal plane

Tin disulfide (SnS2) − a post-transition metal dichalcogenide − is a promising non-precious metal catalyst for the hydrogen evolution reaction (HER). However, the practical application of SnS2 for electrocatalytic HER is hampered by its poor electrical conductivity and catalytic performance at the basal plane. Herein, by doping 14 main-group elements on the S-defective SnS2 monolayer, the most promising SnS2-based catalysts for the HER are screened through density functional theory (DFT) calculations. Interestingly, the Sb/Ga atoms anchored on the S-defective SnS2 basal plane are judged to possess excellent HER performance, yielding almost nearly zero Δ GH (Δ GH = −0.07 and −0.178 eV, respectively), which is even better than that of platinum (Pt) catalysts. Based on the density of states (DOS), the improved catalytic performance is attributed to the introduction of Sb/Ga atoms, which enhance the conductivity of the pristine SnS2 surface and provide unoccupied states near the Fermi energy level, effectively reducing the energy barrier for charge transfer between the H radical and the M@ SnS2 surface. It has also been confirmed by an investigation of the electronic properties resulting in the HER activity improvement, including the crystal orbital Hamiltonian population (COHP), the Bader charge, and the charge difference density (CDD). This work reveals a promising strategy to activate the SnS2 basal plane for HER.