“…The binding energy formula is as follows: , E b = E normalTM @ normalHfS 2 − E TM − E normalHfS 2 where E TM@HfS2 , E TM , and E HfS2 represent the energies of the TM-decorated HfS 2 monolayer, a TM(Co/Rh/Ir) atom, and an HfS 2 monolayer, respectively. The adsorption energy is used to represent the adsorption strength of different gases on the substrate, so the adsorption energy formula is as follows: , E a = E normalgas / normalsubstrate − E gas − E substrate where E gas/substrate , E gas , and E substrate represent the energy of the substrate with adsorbed gas molecules, gas molecules, and substrate, respectively. The substrates here include a Co@HfS 2 monolayer, Rh@HfS 2 monolayer, and Ir-HfS 2 monolayer, respectively.…”