The structural, electronic and photocatalytic properties of five vacancy-containing 2D BiI₃ monolayers are investigated by the first-principle calculations. The electronic structures show that the five structures are stable and have comparable binding energies to that of the pristine BiI₃ monolayer, and the defects can tune the band gaps. Optical spectra indicate that the five structures retain high absorption capacity for visible light. The spin-orbit coupling (SOC) effect is found to play an important role in the band edge of defective structures, and the V_Bi and V_Bi-I3 defective BiI₃ monolayers can make absolute band edges straddle water redox potentials more easily.

通过第一性原理计算研究了五个含空位的2D BiI ₃单层的结构，电子和光催化性能。电子结构表明这五个结构是稳定的，并且具有与原始BiI ₃单层相当的结合能，并且缺陷可以调节带隙。光谱表明，这五个结构保留了对可见光的高吸收能力。发现自旋轨道耦合（SOC）效应在缺陷结构的能带边缘中起重要作用，而V _Bi和V _Bi-I3缺陷的BiI ₃单层可以使绝对能带边缘更容易跨越水氧化还原电势。